© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

SURFACE TREATMENT FOR IMPROVEMENT OF COEFFICIENT OF FRICTION ON SLIDING SURFACES

Ikuo TANABE¹, Ye Htut SOE², Tetsuro IYAMA^3
1Nagaoka University of Technology, Dept. of Mechanical Engineering
²Nagaoka University of Technology, Dept. of Information Science and Control Engineering
³Nagaoka University of Technology, Educational Affairs Section, Mechanics and Machinery Group

Abstract

Recently, many micro structure products are used for compact, high precision and others functions in the field of measuring instruments, medical instruments, information processing devices and so on. However, in the small sliding parts of these products, the surface contact pressure becomes lowered and then, higher adhesive force occurs, resulting larger coefficient of friction. On the other hand, in the field of machine tools, lubrication free sliding parts are also demanded for eco-friendly. In this study, the surface treatment for improvement of coefficient of friction for both light load and heavy load applications are investigated. When laser ray is applied on stainless steel surface, CrO2 layer with small concaves like dimple is generated. This CrO2 layer is used in light load applications. Next, TiAlN and DLC coating are being used on cutting tools for reducing coefficient of friction and cutting heat. Therefore, these coating materials are used for heavy load and oil free applications. The improvement of coefficient of friction and life of coating are investigated by experiments. It was concluded from the results that; (1) Coefficient of friction for light load application can be reduced by coating CrO2 layer. (2) Coefficients of friction for heavy load application were reduced by coating TiAlN and DLC layer. (3) Life of both CrO2 and DLC layers are sufficiently long for practical applications at light load and heavy load respectively.

Author Keywords :

tribology, friction, micro-machine, laser machining, surface treatment,DLC, stable behavior

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

SURFACE INTEGRITY OF HARD TURNED PARTS MODIFIED BY BALL BURNISHING

Wit GRZESIK¹, Krzysztof ZAK¹, Mariusz PRAZNOWSKI^1
1Faculty of Mechanical Engineering, Opole University of Technology, Poland

Abstract

The purpose of this research is to test the applicability of ball burnishing for improving surface integrity produced in hard machining on parts made of high-strength, low alloy 41Cr4 steel with hardness of about 57 HRC. Machined surfaces were characterized using 2D and 3D scanning techniques. Moreover, the distribution of microhardness beneath the surface was determined and the microstucture of the sublayer was examined using SEM/EDS technique. This investigation confirms that ball burnishing allows producing surfaces with acceptable surface roughness and better service properties. The main conclusion is that this sequential technology can partly eliminate grinding operations when hard machining is not enough to produce the desired surface integrity.

Author Keywords :

hard turning, CBN tool,burnishing, surface roughness, surface integrity

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

LAPPING SYSTEM FOR IMPROVEMENT OF GEOMETRICAL ACCURACY USING LATHE MACHINE

Ye Htut SOE¹, Ikuo TANABE², Tetsuro IYAMA³, Junior Raimundo DA CRUZ^2
1Nagaoka University of Technology, Dept. of Information Science and Control Engineering
²Nagaoka University of Technology, Dept. of Mechanical Engineering
³Nagaoka University of Technology, Educational Affairs Section, Mechanics and Machinery Group

Abstract

The geometrical accuracy of the products are essential for high quality and interchangeability. Lapping processing is mostly using for final improvement of geometrical accuracy. Geometrical accuracy includes cylindricity, circularity and straightness. In this paper, lapping processin using a normal lathe was investigated for improvement of geometrical accuracy. Firstly, normal turning process is taken and then, the lapping process is performed using the same lathe. The lapping tool consists of a lapping head made of polypropylene (PP), a coil spring for supplying lapping pressure and holder for fitting on tool post. Lapping slurry is composed by mixing water, PEO (Polyethylene Oxide) and diamond grain. This lapping slurry is supplied between the work piece and the lapping head during lapping processing. The lapping head is made to contact and leave from work piece in regular intervals for catching new grains and removing chips. The optimum lapping condition was invesigated for high productivity and high accuracy by experiments. It is concluded from the results that; (1) The geometrical accuracy were improved by using developed lapping system with ordinary lathe machine. (2) The optimum lapping condition was revealed experimentally. (3) The surface roughness and dimensional accuracy are also improved using this developed lapping system.

Author Keywords :

lapping, lathe, deviation of form, high quality

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

CHARACTERIZATION OF BAND SAWING BASED ON CUTTING FORCES

Tilen THALER¹, Ivan BRIC¹,Rudi BRIC¹, Primoz POTOCNIK²,Peter MUZIC²,Edvard GOVEKAR^2
1PE-TRA Machines, Ljubljana, Slovenia
²University of Ljubljana, Faculty of Mechanical Engineering, Slovenia

Abstract

Band sawing is one of the most efficient methods for which in general it is known that uneven tool wear, chatter and cutting blade defects can affect cutting performance significantly. A data acquisition system was arranged on an industrial band saw machine in order to characterize the band sawing process based on measurements of forces. In this paper, the cutting force signals are analyzed in order to demonstrate important relations to workpiece and cutting blade properties.It is shown that cutting forces contain information about inhomogeneity of a cut workpiece. Signals of cutting forces also reveal important properties of blade geometry that is related to uneven blade wear. Discontinuities such as blade welding are clearly evident in force signals and it is shown that unevenness of blade backing geometry can cause a significant variation in forces due to wedging between the workpiece and a blade support. An original method for blade shape extraction from force signals is presented in detail. Paper also reports on chatter phenomena observed at specific cutting conditions. Possible solutions to the addressed problems and phenomena are discussed in the conclusion.

Author Keywords :

band sawing, cutting forces, condition monitoring, tool wear, chatter

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

COGNITIVE FAILURE CLUSTER ENHANCING THE EFFICIENCY AND THE PRECISION OF THE SELF-OPTIMIZING PROCESS MODEL FOR BEVEL GEAR CONTACT PATTERNS

Robert SCHMITT¹, Christian NIGGEMANN¹,Matthis LAASS^1
1Laboratory for Machine Tools and Production Engineering, RWTH Aachen University, Germany

Abstract

The contact patterns of bevel gear sets are an important indicator for the acoustic quality of rear axle drives. The contact patterns are the result of complex interactions in the production process. This is due to many process steps, numerous influencing factors and interdependencies. In general, their effect on product variations is not fully comprehended. This impedes the design and control of the production process based on a holistic analytical model for new variants fulfilling the acoustic requirements. The approach with self-optimization is possible but can take a long time for the training of the artificial neural networks and the necessary iterations until a satisfying precision for the predicted process parameters is achieved. Also it can occur that the algorithm is not converging and therefore no satisfactory result is turned out at all. In this paper an approach is presented combining the flexibility of self-optimizing systems with the higher precision of delimited solution finders called the Cognitive Failure Cluster (CFC). The improvements provided by the clustering of the optimization program are evaluated regarding the training time and the precision of the result for a production lot of bevel gear sets.

Author Keywords :

cognition, classification, self-optimization,gear testing, contact pattern

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

DEVELOPMENT OF LAPPING TOOLS FOR MIRROR-LIKE SURFACE PROCESSING OF CEMENTED CARBIDE DIE

Ye Htut SOE¹, Ikuo TANABE²,Tetsuro IYAMA³,Shinji NISHIYAMA^2
1Nagaoka University of Technology, Dept. of Information Science and Control Engineering
²Nagaoka University of Technology, Dept. of Mechanical Engineering
³Nagaoka University of Technology, Educational Affairs Section, Mechanics and Machinery Group

Abstract

Recently, cemented carbide dies are used for many industrial products, due to their high stiffness and long life. Electric discharge machining is conventionally used and then, hand lapping is finally undergoes for mirror-like finishing of these products. In privious research, a simple lapping system for only plane surfaces of cemented carbide die was developed. In this study, several lapping tools for lapping of side, edge and corner were developed and evaluated by experiments. The system consists of a lapping tool, lapping vessel and conventional NC milling machine. The lapping vessel is placed on the table of the NC machine and the lapping tool is fitted with the spindle of the NC machine. Cemented carbide work piece is sunk and fitted in the lapping slurry and lapping processing is taken using the developed tools. Each lapping tool consists of a coil spring for supplying lapping pressure and the NC program was made possible to move the lapping head to contact and leave the work surface regularly for catching new grains and dressing. These lapping tools were finaly evaluated by experiments. It is concluded from the results that the developed lapping tools were capable of lapping side, edge and corner of the cemennted carbide work pieces for mirror-like surface finishing.

Author Keywords :

lapping, die, cemented carbide, mirror-like surface, finishing

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

ESTIMATION TOOL FOR OPTIMUM CUTTING CONDITION OF DIFFICULT TO CUT MATERIALS

Ye Htut SOE¹,Ikuo TANAB²,Tetsuro IYAMA³,Junior Raimundo DA CRUZ^1
1Nagaoka University of Technology, Dept. of Information Science and Control Engineering
²Nagaoka University of Technology, Dept. of Mechanical Engineering
³Nagaoka University of Technology, Educational Affairs Section, Mechanics and Machinery Group

Abstract

Titanium alloy and nickel alloy are mainly used for several aeronautical parts due to their high strength and durability at high temperature. However, thermal conductivity of these materials are very low and most of the heat generated during cutting are concentrately conducted into the cutting tool. Therefore, the tool become extremely high temperature resulting shorter tool life. In this paper, a method for calculating the optimum cutting condition for cutting low thermal conductivity materials such as titanium alloy and nickel alloy is developed and evaluated. The temperatures on the cutting tool tip for various combination of tools and work piece materials were calculated by dynamic FEM simulation and the estimation tool for optimum cutting condition is created based on these results. The amount of heat flow and the temperature on the cutting tool were calculated based on cutting theory. Then, optimum cutting conditions for those materials were estimated by newly developed program. The method was finally evaluated by several experiments. It is concluded from the results that (1) The developed program is applicable for estimation of optimum cutting conditions regarding titanium alloy and nickel alloy. (2) Titanium alloy (Ti6Al4V) can be machined with longer tool life using estimated optimum cutting condition.

Author Keywords :

titanium alloy, nickel alloy, cutting machining and calculation model

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

TOWARDS THE DEVELOPMENT OF FEATURE - BASED ONTOLOGY FOR INSPECTION PLANING SYSTEM ON CMM

Slavenko M. STOJADINOVIC¹, Vidosav D. MAJSTOROVIC^1
1University of Belgrade, Faculty of Mechanical Engineering, Serbia

Abstract

The paper define the basic geometrical primitives as classes of Engineering Ontology in order to develop feature - based ontology for Inspection Planning System for CMM. The process of acquisition the properties of individuals and properties of classes is proposed, as one of the main components of Engineering Ontology suitable for implementation in the software for development the ontology - Protégé. The proposed method describes derived geometrical characteristics or characteristics that are measured on the mechanical part. The results indicat that further development of methodology for Engineering Ontology is justified in the field of production metrology and implementation in the appropriate software.

Author Keywords :

engineering ontology, basic geometrical primitives,CMM, protégé

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

RELATION OF PROCESS AND CONDITION MONITORING AT DEEP HOLE DRILLING

Uwe HEISEL¹, Florin SABOU^1
1Institut fuer Werkzeugmaschinen, Universitaet Stuttgart, Germany

Abstract

Process monitoring and condition monitoring are closely related. The basic structure of the tasks is the same. In some cases the may even use the same set of raw data. Monitoring of a process is also influenced by the machine's state. Therefore, the state has to be monitored also. In most cases wear causes a divergence of the intended from the actual state. The paper presents the principles of monitoring the condition of a main spindle as well as monitoring the process of deep hole drilling.

Author Keywords :

process, condition monitorin, deep hole drilling, main spindle

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

ANALYSIS OF SURFACE ROUGHNESS ON BEARING STEEL PARTS AFTER CUTTING, SUPERFINISHING AND BURNISHING OPERATIONS

Miroslaw NESLUSAN¹, Wit GRZESIK², Krzysztof ZAK^2
1Faculty of Mechanical Engineering, University of Zilina, Slovak Republic
²Faculty of Mechanical Engineering, Opole University of Technology, Poland

Abstract

The different technological operation can form the variety of surface with the different functionality. In this paper the surface texture produced by hard turning of a quenched 100Cr6 steel of 62-64 HRC hardness using mixed ceramic (MC) tools and subsequent superfinishing and multipass burnishing operations is characterized by means of a number of roughness parameters. Both conventional and wiper MC cutting tool inserts were employed. The main objective of this study is to improve service properties of the turned surfaces of bearing parts by additional removal and non-removal treatments in order to obtain smoother surfaces with lower surface roughness and better bearing characteristics.

Author Keywords :

hard turning, CBN tool burnishing, superfinishing, surface roughness

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

A MODEL OF PLANT DEVELOPMENTS UNDER CHANGEABILITY ASPECTS

Markus HARTKOPF¹, Engelbert WESTKAEMPER^2
1GSaME, Universität Stuttgart, Bosch Rexroth AG,
²GSaME, Universität Stuttgart, Fraunhofer IPA, IFF, Germany

Abstract

High flexibility and strategic adaptability are two of the major challenges for manufacturing companies, who have to survive in a turbulent environment. They have to recognise the need for change and innovation on all company levels at an early stage in order to be in the position to implement necessar changes of production structures in a timely manner. In order to make necessary investments in a timely manner, producing companies have to adjust direct and indirect object, structures and processes of the system of performance according to the wishes of customers. Early planning calls for a detailed understanding of the existing processes, structures of resources and the experiences which led to their development. An analysis of the past developments is the necessary foundation fo a long term planning of future plant developments. In this paper, a method is proposed for a systematic analysis of past developments of the production structures that consider the specific needs of a plant. The method is the foundation for strategic planning of manufacturing structures and provides the architecture to consider future changes of markets, products and technologies within forecasts and scenarios.

Author Keywords :

plant developments,changeability,manufacturing

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

ELECTROCHEMICAL MICROPROCESSING ASSISTED BY DIODE PUMPED SOLID STATE ND:YAG PULSE LASER

Dominik WYSZYNSKI¹, Sebastian SKOCZYPIEC¹, Marcin GRABOWSKI¹,Adam RUSZAJ¹,Piotr LIPIEC^1
1Cracow University of Technology, Faculty of Mechanical Engineering

Abstract

The use of hybrid machining methods for parts and devices production become more and more attractive nowadays. The paper presents results of modelling use of DPSS (Diode Pumped Solid State) pulse laser for intensification of electrochemical processes in machine part production. Application of DPSS pulse laser enables possibility to reach high level of localization in both machining and growth processes. Laser beam energy accelerates electrochemical processing, improves process localization and prevents other than the machined surface passivation. These conditions should improve electrochemical micro part precision of manufacturing by means of shape and dimensional accuracy in both machining and growth ECM processing.

Author Keywords :

electrochemical machining,laser beam machining, micromachining

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

TECHNICAL ASPECTS OF COAL DISINTEGRATION USING HIGH PRESSURE WATER JET

Przemyslaw BORKOWSKI¹, Jozef BORKOWSKI¹, Michal BIELECKI^1
1Institute of Unconventional HydroJetting Technologies, Koszalin University of Technology, Poland

Abstract

The high-pressure water jet comminution of coal is presents in the paper. For such procedure a special prototype of hydrojetting apparatus have been developed. Three different types of coal were examined: hard-, brown-, and charcoal. Obtained results point out that high-pressure water jet usage for such a purpose is very effective. Brown coal is slightl for charcoal. Such micronization effect gives even over 100,000 times increase Moreover charcoal susceptibility for intensive hydro-comminution causes that one can get the most comminuted structure what is a good prognosis for its modification into bio-fuels.

Author Keywords :

high-pressure water jet, coal, disintegration

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

MATHEMATICAL MODELLING OF THE LASER MACHINING PROCESS OF SAPPHIRE CRYSTAL Al2O3

Dominik WYSZYNSKI¹, Sebastian SKOCZYPIEC¹, Karolina FURYK^1
1Cracow University of Technology, Faculty of Mechanical Engineering, Poland

Abstract

The paper presents theoretical aspects concerning use of pulse laser source for precise machining of Al2O3 crystals for medical applications. The scheme of laser beam manipulation and the test stand has been presented. Application of the mathematical model enabled determination of values of basic sapphire machining parameters. Presented results give rough information about dynamics of the process and can be used for the test stand designing as well as determination of machining precision.

Author Keywords :

laser beam machining micromachining, sapphire

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

THICKNESS EVALUATION OF THE CARBON COATINGS MANUFACTURED ON MAGNESIUM ALLOYS USING OPTICAL PROFILER

Marcin GOLABCZAK¹, Philippe JACQUET^2
1Technical University of Lodz, Poland
²École Catholique d'Arts et Métiers, Lyon, France

Abstract

One of the problems in identification of carbon nanocoatings is measurement of their thickness. There are a lot of methods which allow for determination of thickness i.e. SEM analysis of cross section of sample with manufactured coating, nanoindentation analysis with using DSP (Digital Signal Processing) method, roughness analysis with using different kind of profilers. In this paper the technology of manufacturing of carbon coatings on AZ31 magnesium light alloy has been depicted and optical profiler has been used for thickness evaluation of these coating. Obtained results allowed for precise estimation of manufactured carbon coatings thickness. In this way it was also possible to compare obtained thickness results with thickness evaluated by other methods.

Author Keywords :

AZ31 magnesium alloy, PACVD technology,carbon coating, optical profiler, roughness parameters

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

PROPERTIES OF PVD COATINGS MANUFACTURED ON X38CrMoV5-1 STEEL FOR PLASTIC MOULDING APPLICATIONS

Marcin GOLABCZAK¹, Wojciech PAWLAK¹, Witold SZYMANSKI¹,Philippe JACQUET²,Romain FLITI^3
1Technical University of Lodz, Poland
²École Catholique d'Arts et Métiers, Lyon, France
³Centre Arts et Métiers, Cluny, France

Abstract

In plastics moulding industry a lot of parts sustain in relative movement: ejectors, slides, dies, etc. Some seizing or micro-welding may appear, especially when lubrication is not used. In this paper, PVD coatings have been obtained thanks to hybrid Cathodic Arc Evaporation system. Several properties of the coatings have been investigated such as chemical composition, microstructure, friction coefficient at ambient and high temperature conditions, nanohardness and their modulus of elasticity.

Author Keywords :

X38CrMoV5-1 steel, PVD technology, TiC+a-C:H coating, MoS2TiW coating, friction coefficient, nanohardness

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

TRIBOLOGICAL ASPECTS OF SOME MATERIALS ABRASIVE-WATER JET CUTTING

Henryk HOLKA ¹, Maciej MATUSZEWSKI ¹, Janusz MUSIAL ¹,Michal STYP-REKOWSKI^1
1Faculty of Mechanical Engineering, University of Technology and Life Sciences in Bydgoszcz, Poland

Abstract

This article presents results of comparative studies into the roughness (very significant tribological factor) of surfaces cut using the AWJM method. Cutting was performed on samples made of quenched and tampered alloy steel (1.2080), plastic (polyamide PA6) and mineral material (syenite). Variable parameters in the cutting process included: jet pressure and feed. As a result of measurements involving selected roughness parameters (Ra, Rz and Rq), it was discovered that the majority of variable factors had a significant effect on the cut surface roughness. It was also demonstrated that the contact method measurements cannot be performed with regard to plastics because the results are characterised by a very great scatter of results values, making them unreliable.

Author Keywords :

abrasive-water jet machining,cutting, roughness parameters, steel, plastics, syenite

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

SOME OPERATIONAL FEATURES OF COATING OBTAINED WITH PACVD METHOD

Monika MADEJ¹, Dariusz OZIMINA¹, Krzysztof KURZYDLOWSKI²,Tomasz PLOCINSKI²,Piotr WIECINSKI², Michal STYP-REKOWSKI^3
1Kielce Technology University, Poland
²Warsaw University of Technology, Poland
³Faculty of Mechanical Engineering, University of Technology and Life Sciences in Bydgoszcz, Poland

Abstract

The main aim of presented work was the commencing the tests and analysis of the DLC type a:C:H coatings obtained with PACVD technique on the elements from Co-Cr-Mo alloys., among others: monitoring of structure changes, hardness measurement, estimation of the surface geometrical structure and tribologic tests. The analysis of surface structure and its elementary composition were estimated with the application of scanning SEM microscope, as well as TEM transmission microscope. The hardness of the elements with and without the coating was measured with the Matsuzawa micro hardness testing tester. Tribologic test of materials wear resistance was done with using T-01M apparatus ball-on-disc type, within a set of Al2O3 ball - disk from Co-Cr-Mo alloys with DLC coating, in technologically dry friction condition as well as with Ringer solution lubrication. Friction tests were conducted with using tester T-17, working in association: polymer pin made of high-molecular polyethylene PE - UHMW - plate from Co-Cr-Mo alloys with DLC coating with Ringer solution lubrication.The results obtained during mentioned above tests showed that the application of DLC coatings greatly enhances the operating features of the coated surfaces.

Author Keywords :

amorphous carbon film, DLC coating friction, wear

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

EFFECT OF GRANULARITY OF REINFORCING PARTICLES Al2O3 ON EDM PROCESS OF ALUMINIUM MATRIX COMPOSITES

Jan PERONCZYK¹,
¹University of Ecology and Management, Warszawa, Poland

Abstract

The study discusses issues related to the process of electro-discharge machining (EDM) composites based on Al + 20% Si + 5% Fe + 3% Cu + 1% Mg matrix manufactured using a powder metallurgy method. Ten percent by volume of Al2O3 grains of 3, 9, 23 and 53?m sizes with irregular sharp edges represented the reinforcing phase. EDM was performed with a machine equipped with a RLC generator using different (computational) discharge energies varied in steps within the 0.044 - 2.268mJ range. The tests measured volumetric productivity of EDM (Vw) and roughness (Ra) of the machined surface. In addition, the researchers provided selected SEM images of ED-machined surfaces with some results of X-ray microanalyses of chemical composition performed in cavities and on the surfaces of irregularities. They also provided SEM images of Al2O3 grains adhering to the machined surface of the composite, showing the mechanism of erosion of dielectric particles in EDM conditions. They demonstrated that the energy of single discharges (Ei) was the main parameter effecting the process and results of EDM. The volumetric productivity of the process (Vw) and roughness of the machined surface (Ra) increase with growth of energy (Ei) and, at the same time, surface integrity (SI) changes.

Author Keywords :

aluminium composites, reinforcing phase, electro-discharge machining

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

ABLATIVE LASER CLEANING OF LACQUER COATING

Wojciech NAPADLEK¹, Izabela KALMAN^1
1Military University of Technology, Mechanical Faculty, Warszawa, Poland.

Abstract

The paper presents the selected results of tests on ablational laser removal of polymer lacquer coating with metallic filler (aluminium plates). The fibre laser with the Galvo head of the following parameters: the radiation wavelength ? = 1064nm, the exposition time of the laser impulse ? = 25ns, and the repetition frequency 30-500kHz was used. By changing the power thickness, repetition frequency, and scanning speed various effects of varnish, coating removal were obtained. The melting of the colourless lacquer coat was observed when small power thickness was applied. Multiple scanning with the laser beam of higher power thickness resulted in sequential removal of several to tens of micrometers of the lacquer coating. This technology brings very good perspectives for the renovation of lacquer coating systems in present vehicles (bodies, frames).

Author Keywords :

laser ablation cleaning, lacquer coats

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

RESEARCH OF ELECTROLYTE LOW LOSS IN TYPICAL ECM GAPS

Tomasz PACZKOWSKI¹, Jaroslaw ZDROJEWSKI², Slawomir BUJNOWSKI²,Daniel JANICKI^1
1The Faculty of Mechanical Engineering, University of Technology and Life Sciences in Bydgoszcz, Poland
²The Faculty of Telecommunications and Electrical Engineering, University of Technology and Life Sciences in Bydgoszcz, Poland

Abstract

This paper presents the results of research of hydraulic loss during electrolyte flow through gaps typical for ECM machining. The research was conducted on a test station where inducing an oscillatory movement of electrodes was possible. Appropriately prepared electrodes with curvilinear outlines were placed in a machining unit which allowed for measuring the pressure of the electrolyte flow in eight points on the electrode surface and also interelectrode gap inlet and outlet. Additionally, the results of pressure measurements were compared with results obtained from a computer simulation.

Author Keywords :

ECM, electrolyte flow loss, curvilinear electrode surfaces

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

SURFACE MODIFICATION OF TITANIUM USING THE COMPLEX TECHNOLOGIES

Yurij SHALAPKO¹, Natalia MASHOVETS¹, Norbert RADEK²,Tomasz KALACZYNSKI^3
1Khmelnitsky National University, Ukraine
²Kielce Technology University, Poland
³Faculty of Mechanical Engineering, University of Technology and Life Sciences in Bydgoszcz, Poland

Abstract

In this paper the results of experimental research of microhardness, thickness, phase composition and wear resistance of pure titanium surface layer after laser treatment with different regimes and next nitriding in a glow discharge in hydrogen-free medium were presented.

Author Keywords :

laser treatment, nitriding, titanium, wear resistance, microhardness,phase composition

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

INVESTIGATION OF THE SHAPE ACCURACY OF CYLINDRICAL HOLES MACHINED BY EDM PROCESS

Slawomir SPADLO¹, Dominik DUDEK^1
1Kielce University of Technology, Faculty of Mechatronics and Machine Building, Poland

Abstract

The paper deals with the investigations of influence parameters of electrodischarge machining (EDM) on the shape accuracy of holes machined by EDM process. BP-95. machine with electronic generator type was used to perform EDM process. Kerosene was used as a dielectric. During EDM process the parameters of current were permanent. The shape of electrode and way of passing dielectric were changed. The following parameters were determined: productivity of EDM proces and shape accuracy of the drilling holes. The accuracy of bored cylindrical holes, is highest in case of hollowing out with the tubular electrode and for sucking out working liquid by her inner life. In the case of hollowing out with the electrode tubular, sinking the tube with pumping liquid by the inner life is the most favourable method causing the smallest mistakes of outlines of the cylindrically shape. The time of boring the arterial hole is shortest in case of hollowing out with the electrode tubular and for pumping working liquid by inside.

Author Keywords :

electrical discharge machining, hole drilling, shape accuracy.

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

IDEA OF THE EXPERIMENTAL STAND FOR MICRO-ELECTRICAL DISCHARGE MACHINING USING CARBON FIBRES AS THE TOOL ELECTRODES

Anna TRYCH¹, Szymon MARKIEWICZ^1
1Faculty of Mechatronics, Warsaw University of Technology, Poland

Abstract

The paper deals with the idea and design solutions for a special experimental stand and consequently a preliminary study of the future machine tool for micro-electrical discharge machining with carbon fibre as tool electrodes. The main requirements are introduced and, particularly for such purpose unusual conditions that must be assured are presented. Solutions that were used as well as some initial concepts are discussed and assessed. The paper is enriched with an extensive illustrative material of designed solutions for each important part responsible for the proper functioning of the respective components. The evaluation of existing solutions as well as the further issues that must be developed are analyzed.

Author Keywords :

micro-electrical discharge machining,tool electrode, carbon fibres

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

AUTOMATION OF THIN FILM DEPOSITION PROCESS BASED ON MAGNETRON SPUTTERING

Piotr DOMANOWSKI¹, Andrzej WAWRZAK^2
1Faculty of Mechanical Engineering, University of Technology and Life Sciences in Bydgoszcz. Poland
²Department of Technical and Applied Physics, Nicolaus Copernicus University in Toruń, Poland

Abstract

This paper presents the structure of a flow processing line implemented in domestic industry and designed for thin film deposition over large surfaces in an atmosphere of argon and reactive gases. The design of the line has been developed based on original pumping cycle and magnetron sputtering control systems.

Author Keywords :

production automation, magnetron flow production line

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

DESIGN METHOD OF PRODUCTS' PROCESSES FOR GROUP TECHNOLOGY

Janusz MLECZKO^1
1University of Bielsko-Biała, Department of Industrial Engineering, Bielsko-Biała, Poland

Abstract

In contrast to the traditional manufacturing system, where the basic features are low product variety and mass production, recent manufacturing environment is characterized by shorter product life cycles, constantly diminishing batch sizes while the variety of product types and models continues to increase. In high-variety manufacturing , in spite of applying modern management techniques, setup time still plays an important part in the production cycle time. Product development teams use many methods and tools for design, test, and manufacture a new or improved product. Design for manufacturing methodologies are used to improve a product's manufacturability. For high-variety production the cumulative amount of setup time results from the number of changeovers. To shorten the production time and therefore cost the methods of group technology (GT) are used. This paper presents a method of increasing the manufacturability of elements produced in GT. The method was validated in the conditions of best practice production for high-variety production.

Author Keywords :

group technology,mass customization, costs,product family, manufacturability

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

MULTISTAGE DECISION MAKING PROCESS OF MULTICRITERIA PRODUCTION SCHEDULING

Krzysztof KALINOWSKI^1
1Silesian University of Technology, Faculty of Mechanical Engineering, Institute of Engineering Processes Automation and Integrated Manufacturing Systems, Poland

Abstract

In this paper the multicriteria optimisation problem in scheduling of discrete manufacturing systems is presented. The proposed method is an extension of work on integrated management system for variable and multiassortment production to order in small and medium-sized enterprises (SMEs) that is developed in the Institute of Automation Processes Engineering and Integrated Manufacturing Systems of Silesian University of Technology. Particular attention was paid to discuss the scheduling system operating conditions in an integrated environment - a system operating in real time. The proposed method indicates different decision-making stages to be taken in scheduling, from defining the problem, determining the structure of the production system, constraints and objective function, up to the generation and evaluation of solutions. The various approaches of decision maker participation in the process of finding the best solution are taken into account: a priori, posteriori and interactive.

Author Keywords :

scheduling, decision making, multicriteria optimisation

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

PLANNING AND SCHEDULING OF WORK IN ROBOTIC MANUFACTURING SYSTEMS WITH FLEXIBLE PRODUCTION

Adrian KAMPA^1
1Silesian University of Technology, Institute of Engineering Processes Automation and Integrated Manufacturing Systems, Poland

Abstract

Industrial robot are more and more used in industry because of their speed and accuracy. Robots can work 24 hours a day, but for best performance the robot movements must be planned in detail. In the article the problem of planning and scheduling of robotic work is described. An example of robotic system with three machines is given and analysed. Simulation model of the robotic system is also presented. On basis of the simulation model some simulation experiments have been carried out. Robots work best in determined production conditions. In experiment the influence of flexible production with variable production conditions on robotic system performance has been studied. Carried out simulations show influence of robot speed and machines work time on the system productivity. Also the bottleneck effect has been studied.

Author Keywords :

planning, scheduling,robotics, robot cycle time

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

FORMULATION OF A SEQUENCING PROBLEM IN A MIXED-MODEL PRODUCTION SYSTEM

Damian KRENCZYK¹, Marcin ZEMCZAK^1
1Silesian University of Technology, Faculty of Mechanical Engineering, Institute of Engineering Processes Automation and Integrated Manufacturing Systems, Poland

Abstract

In the paper the problem of production orders sequencing in a mixed-model production system is considered. The authors present the design of the system and production orders, manufactured in the system. Model of the system consists of an input buffer and an assembly line with a given number of stations. The system is presented in a simplified manner, which provides the ability to compare it (under certain assumptions) with a real system. A virtual model of the mixed-model production system has been created. The main objective is to verify the correct operation of the prepared simulation model and the possibility of generating of input data and acquisition of output data in a mixed-model production system. The question is whether such model can be used to simulate the operation of a mixed-model production system in a manner that represents the outcome of a real system.

Author Keywords :

sequencing, simulation, mixed-model production system

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

TOTAL PRODUCTION MAINTENANCE AND ROBUST SCHEDULING FOR A PRODUCTION SYSTEM EFFICIENCY INCREASING

Iwona PAPROCKA^1
1Silesian University of Technology, Faculty of Mechanical Engineering, Institute of Engineering Processes Automation and Integrated Manufacturing Systems, Poland

Abstract

In the paper, the proposition of application of two methodologies: the predictive scheduling and Total Productive Maintenance - TPM to increase efficiency of a production system is presented. In this paper, an example of problem of predicting a time of a bottle neck failure is presented. Using the Statistica program, histograms that show the graphical relationship of a number of observations and failure-free times of the bottle neck for historical periods are created. The fitting of the histograms to the theoretical distributions: normal, exponential, gamma and Weibull using appropriate tests (for example the Kolmogorov-Smirnov test for normal distribution) is researched. After finding distribution and setting parameters for historical periods, for the next scheduling horizon values of parameters are extrapolated using the regression method in the Statistica program. For the bottle neck various reliability characteristics are computed. Having the Mean Time To Failure (MTTF) and Mean Time of Repair (MTTR) of the bottle neck, robust schedule is generated. At the time of the predicted failure, preventive actions and technical survey of the machine are scheduled. The production system is modeled in the simulation program - Enterprise Dynamics 8.1.

Author Keywords :

total productive maintenance,robust scheduling, modeling, simulation

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

A NUMERICAL EXAMPLE OF TOTAL PRODUCTION MAINTENANCE AND ROBUST SCHEDULING APPLICATION FOR A PRODUCTION SYSTEM EFFICIENCY INCREASING

Iwona PAPROCKA¹, Dorota URBANEK^1
1Silesian University of Technology, Faculty of Mechanical Engineering, Institute of Engineering Processes Automation and Integrated Manufacturing Systems, Poland

Abstract

In the paper, the proposition of application of two methodologies: the predictive scheduling and Total Productive Maintenance - TPM to increase efficiency of a production system is presented. In this paper, an example of problem of predicting a time of a bottle neck failure is presented. Using the Statistica program, histograms that show the graphical relationship of a number of observations and failure-free times of the bottle neck for historical periods are created. The fitting of the histograms to the theoretical distributions: normal, exponential, gamma and Weibull using appropriate tests (for example the Kolmogorov-Smirnov test for normal distribution) is researched. After finding distribution and setting parameters for historical periods, for the next scheduling horizon values of parameters are extrapolated using the regression method in the Statistica program. For the bottle neck various reliability characteristics are computed. Having the Mean Time To Failure (MTTF) and Mean Time of Repair (MTTR) of the bottle neck, robust schedule is generated. At the time of the predicted failure, preventive actions and technical survey of the machine are scheduled. The production system is modeled in the simulation program - Enterprise Dynamics 8.1.

Author Keywords :

total productive maintenance,robust scheduling, modeling, simulation

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

PROJECT ORIENTED PRODUCTION OPTIMIZATION

Bozena SKOLUD¹, Bozena MARCINCZYK^1
1Silesian University Of Technology, Faculty of Mechanical Engineering, Institute Of Engineering Processes Automation And Integrated Manufacturing Systems, Gliwice, Poland

Abstract

In this paper the resource - constrained scheduling problem is discussed. The objective function is minimization of makespan under constrained resources and due time. The metaheuristic based on Ant Colony Optimization (ACO) is proposed for multi-project scheduling. The elaborated method, algorithm and example illustrating ACO application for the multi-project scheduling problem is presented.

Author Keywords :

ant algorithm, project scheduling, project oriented production management,

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

DIFFERENT STRUCTURES OF MANUFACTURING SYSTEMS IN LOW PRODUCTION DEMAND

Waldemar GRZECHCA¹,
¹Silesian University of Technology, Faculty of Automatic Control, Electronics and Computer Science, Gliwice, Poland

Abstract

Since more than 100 years ago a simple assembly line was introduced in the American Ford automotive factory. Nowadays we can find papers and books with description of different structures and different kinds of production. This article deals with the problem of low production demand which is coming from the market and considers three different manufacturing structures: single (straight) assembly line, U-line and assembly round table. The description of all above mentioned structures is given. The fundamental assumptions according to balancing problem are shown. Selected heuristics methods for solving assembly line balancing problem are described. Advantages and disadvantages of these structures are considered. Also numerical examples are calculated and final results are estimated (smoothness index, line efficiency, time of line, number of turns for rotating round table). At the end the conclusions and remarks are presented.

Author Keywords :

assembly line balancing problem, heuristic methods,final results estimation

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

GRINDING AND FINISHING SCULPTURED SURFACES USING AN INNOVATIVE MULTITOOL HEAD WITH INDEPENDENT PNEUMATIC DRIVE

Jan BARAN¹,Jaroslaw PLICHTA^1
1Koszalin University of Technology, Faculty of Mechanical Engineering, Department of Production Engineering, Poland

Abstract

The paper presents the concept and prototypes of multitool grinding and polishing head with independent pneumatic drive for grinding and finishing large free form surfaces (FFS). Such a head facilitates selection of elastic abrasive discs, grinding process parameters and conditions, as well as proper shaping of the marks of the workpiece surface geometric structure.

Author Keywords :

tribology, friction, micro-machine, grinding, polishing, interchangeable abrasive discs, sculptured surfaces

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

THE SHAPE OF ABRASIVE GRAIN GENERATING METHODS IN NUMERICAL ANALYSIS

Monika FORYSIEWICZ¹, Leon KUKIELKA^1
1Koszalin University of Technology, Department of Mechanical Engineering, Poland

Abstract

The aim of this work is to present the methods of abrasive grain numerical model geometry generation based on analysis of real grain pictures. The methodology of abrasive grain shape generation, for three different images analysis methods, was presented. Obtained an irregular geometry of abrasive grains. The possibility of implementation of irregular numerical grain models into the ANSYS program, will allow to the modeling and numerical simulation of machining process at higher accuracy of numerical results (the numerical model will have reduced simplifications in relative to the real machining process). The numerical results will be subjected to experimental verification and may provide a basis for further modeling studies in this scope.

Author Keywords :

abrasive grain, modeling, Ansys/Ls-Dyna, surface layer

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

SURFACE EVALUATION DURING THE GRINDING PROCESS USING ACOUSTIC EMISSION SIGNAL

Pawel SUTOWSKI^1
1Koszalin University of Technology, Department of Mechanical Engineering, Poland

Abstract

The hereby article presents results of experimental tests which prove the possibility of indirect evaluation of the grinded object's quality with the application of monitoring and analysis of selected acoustic emission signal (AE) registered during the machining process. As the grinding process is carried out and the grinding wheel wear progresses, the acoustic emission signal value is shaped adequately to the workpiece surface quality changes. The binding descriptor of changes of roughness profile and material residual stresses is the RMS value of the acoustic emission signal and in particular the statistical features that characterize the distribution of values contained in the signal sample in relation to the average value. The analysis results indicate that the acoustic emission signal is a convenient indicator for evaluation of stresses cumulated in the surface layer of the material and in selected surface geometrical structure parameters.

Author Keywords :

surface, roughness, grinding process,acoustic emission signal

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

EFFECT OF SUPERFINISHING METHODS KINEMATIC FEATURES ON THE MACHINED SURFACE

Wojciech KACALAK¹, Katarzyna TANDECKA^1
1Koszalin University of Technology, Division of Precision Mechanics, Poland

Abstract

The carried out research of the processes for the treatment of superfinishing with the application of microfinishing films of IMFF type with heaping the grain from the alundum with the nominal size of 15 micrometers for the different cinematic system proved that the topography of surface after smoothening depends on the cinematic features of process. It is demonstrated that the machining with oscillation can be substituted and the similar effects can be obtained as a result of the deviation from the parallelism of the directions of object feed and foil feed. This means the possibility to apply the super finisher attachments with a simpler building.

Author Keywords :

superfinishing, microfinishing film,surface topography

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

BASICS OF THE SUPERFINISHING RESULTS PROGNOSTICATION BY THE DIAMOND LAPPING FILMS

Wojciech KACALAK¹, Katarzyna TANDECKA^1
1Koszalin University of Technology, Division of Precision Mechanics, Poland

Abstract

Superfinishing with the use of diamond lapping films differs to a significant extent from other machining methods. This is finishing surface machining, one which is realized by a slow rewinding of a microfinishing film, putting it in an oscillating motion and pressing the tool to the surface being machined. The surface being machined moves with a speed which is substantially greater than that of the tool feed. A characteristic feature of the process is a one-time use of the tool, the result being a need of an optimal selection of the machining parameters. Investigations of the topography of the microfinishing film surface were conducted with the use of new parameters that describe the arrangement and the shape of the vertices of active grains. The following were used for the purpose of assessment: coefficients that had been developed that describe the features of the shape of the tool surface, such as the standardized coefficient of the flatness of vertices w^N_ki, the standardized number of vertices in relation to an area unit L^N_wi and the dissipation coefficient of te height of the location of vertices w^N_rwi. For the purpose of the assessment of the smoothening ability of diamond lapping films the smoothening potential coefficient wp was developed, which is defined as the geometric mean of the abovementioned indices.

Author Keywords :

microfinishing film, abrasive grain,superfinishing, diamond, coated abrasives

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

RESEARCH ON THE PROCESS OF SUPERFINISHING CERAMIC SURFACES OF CUTTING PLATES

Wojciech MUSIAL¹, Mariola CHOROMANSKA^1
1Koszalin University of Technology, Mechanical Department, Poland

Abstract

This paper presents initial research on the surfaces of cutting ceramic plates ground using diamond grinding wheels. Ceramic materials were ground using a piezoelectric feed-in system whose aim was to minimize the effect of brittle cracking of the ceramic material in the machining zone. Due to precise machining it is possible to smooth out the machined surface by ductile-regime grinding the material removal mechanism and, in consequence, reducing the defects on its surface and in the surface layer of the ground material.

Author Keywords :

ceramic cutting plates, superfinishing surface layer, defects

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

EVALUATION OF THE SURFACE TOPOGRAPHY AFTER PRECISION MACHINING

Robert TOMKOWSKI¹,Wojciech KACALAK¹,Dariusz LIPINSKI^1
1Koszalin University of Technology, Department of Mechanical Engineering, Poland

Abstract

Analysis of the geometric features and determination of the condition of the surfaces machined during an abrasive process is of crucial importance for evaluation of their wear properties. Numerous parameters can be used for assessing topography of technical surfaces. Many of them contain information that is general or poorly correlated with the wear features. The group of parameters used for such purpose should include those that do not cause information redundancy and provide distinct information. Evaluation of the surface geometric structure after precision machining is a difficult process due to the limited scope of unevenness heights that fit within the range of a few micrometers to a few nanometers. In this paper the synthetic indexes of the evaluation of extra smooth surfaces were created, taking into consideration numerous elementary parameters. The value of the synthetic index was determined as the geometric average of the partial indexes which, when compared to the arithmetic average, is more dependent on the data believed to be disadvantageous.

Author Keywords :

extra smooth surfaces, geometric features,surface parameters, machining

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

REVIEW OF THE ADVANCED MICROSCOPY TECHNIQUES USED FOR DIAGNOSTICS OF GRINDING WHEELS WITH CERAMIC BOND

Wojciech KAPLONEK¹, Krzysztof NADOLNY^2
1Koszalin University of Technology, Faculty of Mechanical Engineering, Department of Production Engineering, Poland ² Koszalin University of Technology, Faculty of Mechanical Engineering, Department of Production Engineering, Poland

Abstract

A wide range of abrasive tools is used in modern removal machining techniques. Their condition has significant influence on the quality of the shaped surfaces of the produced elements and the functions they perform. Abrasive tools diagnostics is in this case an essential element of the production process, connected with assessment of the abrasive tool surface condition. Such an assessment can be carried out with microscopic methods The work presents selected microscopic techniques on the cutting edge of technology such as: digital microscopy, confocal laser scanning microscopy and scanning electron microscopy. Characteristics of each of the methods and the applied devices were briefly presented. The experimental part presents exemplary results of measurements and analyses carried out using the described methods. The works were carried out on, among others, grinding wheels with ceramic bond used in internal cylindrical grinding processes. The assessed tools were characterized by a number of features such as impregnated active surface, modified bond microstructure or smearing the active surface with chips of the machined material. The obtained results confirmed the possibility of application of the above-mentioned microscopic techniques in abrasive tools diagnostics.

Author Keywords :

microscopy, abrasive tools,diagnostics

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

APPLICATION OF THE LASER SCANNING MICROSCOPY TO EVALUATION OF ABRASIVE TOOL WEAR

Dariusz LIPINSKI¹, Wojciech KACALAK¹,Robert TOMKOWSKI^1
1Koszalin University of Technology, Department of Mechanical Engineering, Poland

Abstract

Grinding is one of the basic precise machining methods. Evaluation of the abrasive tool surface is the basic criterion of forecasting the tools' durability and the process results. The applied method of laser scanning made determination of the surface coordinates and subsequently of its geometric features with micrometric accuracy possible. Using the information on the abrasive tool surface geometric structure, a methodology of evaluation of the level of changes of the tool during the machining process was developed. The developed method allowed for evaluation of the level of abrasive tools' wear, and subsequently formed foundations for assessment of the influence of the machining parameters on the durability of abrasive tools, evaluation of the influence of the parameters of the process of shaping the abrasive tools' active surfaces on their geometric characteristic and evaluation of the level of correlation between the monitored process parameters and the degree of the abrasive tools' wear.

Author Keywords :

grinding, wear, abrasive tools, surface analysis, monitoring

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2012, Poland

BEHAVIOUR OF ELASTO/VISCO-PLASTIC WORKPIECE MATERIAL DURING MACHINING

Jaroslaw CHODOR¹, Leon KUKIELKA^1
1Koszalin University of Technology, Mechanical Department, Poland

Abstract

Experimental investigations of plastic deformation and uniaxial tension of elasto/visco-plastic (E/V-P) material (41Cr4) were conducted to characterize the flow behavior of the material. Dynamic effects, constitutive damage law and contact with non-linear friction in simulations were described using updated Lagrangian formulation. That model of the process allows defining advanced simulations of tool's penetration in workpiece and chip formation. The yield stress is taken as a function of the strain and the strain rate in order to reflect realistic behavior of unsteady-state process, a material separation criterion based on the failure strain ?f were determined Finite element simulations were carried out using ANSYS code. The influence of the chosen process parameter in numerical simulations on the chip's shapes was presented. Results revealed good agreements between FEM results and experimental ones.

Author Keywords :

machining, modeling,numerical simulations, chip