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Sulima I.,Pedagogical University of Cracow | Klimczyk P.,Institute of Advanced Manufacturing Technology | Malczewski P.,Pedagogical University of Cracow
Acta Metallurgica Sinica (English Letters) | Year: 2014

The AISI316L stainless steel composites reinforced with 2, 4, 6, and 8 vol% titanium diboride (TiB2) particles were sintered by the high pressure-high temperature method. Ball-on-disk method was carried out to study wear behavior of the composites. Tests were carried out at room temperature. The TiB2particles improved the hardness and tribological properties of the composites. The friction coefficient of the composites decreased with the increasing content of TiB2. The reduction of the wear rate with the increasing of the content of TiB2particles in the steel matrix was also observed. It is demonstrated that the friction coefficient of composites with the same content of TiB2particles depend on the sintering conditions. © The Chinese Society for Metals and Springer-Verlag Berlin Heidelberg 2014.


Kozak J.,Institute of Advanced Manufacturing Technology | Skrabalak G.,Institute of Advanced Manufacturing Technology
Lecture Notes in Engineering and Computer Science | Year: 2014

This paper reports the development of the mathematical modeling of an abrasive electrochemical grinding (AECG) process. In AECG a metal-bonded grinding wheel is used instead of a graphite or metal wheel-electrode used in electrochemical grinding (ECG). Therefore, the mechanical abrasion is combined with the electrochemical dissolution. Significant improvements in material removal rates have been observed with AECG of advanced materials, such as superalloys, sintered carbides and metal matrix composites. The interaction of the abrasion and electrochemical dissolution in AECG is analyzed on the basis of computer simulation of the material removal process. The effects of main machining parameters such as feed rate, voltage and grit protrusion is studied.


Gogo J.,Institute of Advanced Manufacturing Technology
11th IMEKO TC14 Symposium on Laser Metrology for Precision Measurement and Inspection in Industry, LMPMI 2014 | Year: 2014

Thermal issues are relatively well developed and described in machine tools and their development is quite rapid in recent decades. This is related to increased awareness of the impact of thermal conditions on the accuracy and efficiency of their work and the increased requirements of users (up to 75% of the overall geometrical errors of machined workpieces can be induced by the effects of temperatures). There is a large stock of published research and case studies aimed at compensation and reduction of thermal error of machine tools. Branch of coordinate measuring machine (CMM) is strongly associated with the machine tool industry. There are a lot of convergence in approach to this theme in both subject groups. Both in the construction of machine tools and measuring machines as the key point of interest is the influence of various physical phenomena on the behavior of the executive point, in the case of measuring machines is the end of the measuring head, in the case of machine tools is a tool centre point (TCP). Considerable amount of research on the effects of thermal phenomena in the case of machine tools is carried out without taking into account the cutting forces, which also conforms research approach in both concerned areas. An important difference, however, is the fact that the compensation of thermal deformation in machine tools must be made immediately during work, if we want to improve the geometric parameters of the workpiece, which involves the introduction of some actuators, or correction of the trajectory in real time. While the result of work of the measurement machine are stored data that can be corrected or processed after the process of measuring and correction does not make any material actuator. Order of magnitude of precision in the case of machine tools and CMM is also different. Thermal phenomena associated with measuring machines are relatively well developed in the case of steady thermal state, and the uniform temperature gradient. Mathematical models are described, compensation systems have been developed. There are publications concerned with selected aspects of the measuring machine work, or selected components that generate heat inside or outside of the machine structure. However problem of modeling of the whole machine and studies of thermal effects, and timevarying or locally occurring phenomenon,based on numerical methods is relatively poorly studied. This probably results from the fact that both numerical methods and hardware have developed enough to address this issue only in recent decades. Important here is the economic aspect (the cost of computing hardware and software), and the performance parameters, which allow the calculation of the real-time close to the real-time or made in acceptable period of time post factum.


Skrabalak G.,Institute of Advanced Manufacturing Technology | Kozak J.,Institute of Advanced Manufacturing Technology | Zybura M.,Institute of Advanced Manufacturing Technology
Procedia CIRP | Year: 2013

Electrodischarge machining in gaseous media is one of the fastest growing branches among institutions involved in the research and development of EDM as green manufacturing process. The paper presents results of the studies in the area of dry electrodischarge machining. There are presented performance characteristics of the process, using various gases and their mixtures as dielectric medium. The main comparison coefficients are tool wear ratio, material removal rate and machining accuracy / quality. Important aspect of dry EDM milling is also the way that gas is supplied to the interelectrode gap. The paper covers comparison, and influence on machining performance, of gas supply method: through electrode and from outside of the electrode. Influence of gas pressure, flow rate and rotational speed of the electrode are also discussed resulting in finding optimal conditions for machining, depending on the optimization criteria. © 2013 The Authors.


Skrabalak G.,Institute of Advanced Manufacturing Technology | Kozak J.,Institute of Advanced Manufacturing Technology
WCE 2010 - World Congress on Engineering 2010 | Year: 2010

In the paper are presented results of simulation and mathematical modelling of the material removal rate of electrodischarge milling process with compressed air as dielectric. There are also presented basic characteristic of the DEDM milling process and comparison of this green machining method with kerosene based EDM milling. Presented results refer to the experiments of micro machining with thick walled electrodes. There are described advantages and drawbacks of this machining method, especially in the field of micro-machining.


Kozak J.,Institute of Advanced Manufacturing Technology | Kozak J.,Polish Institute of Aviation | Zybura-Skrabalak M.,Institute of Advanced Manufacturing Technology
Procedia CIRP | Year: 2016

Electrochemical Machining (ECM) provides an economical and effective method for machining high strength, heat-resistant materials into complex shapes such. ECM is performed without physical contact between the tool and the workpiece in contrast to the mechanical machining. Therefore, surface layer formed during ECM process characterizes with no mechanical distortion, compressive stresses, cracks or thermal distortions. This paper presents some features of ECM processes, such as the effect of heterogeneous structure of material workpiece and the influence hydrodynamic instability of anode boundary layer on the surface roughness. A mathematical model was developed to simulate the evolution of surface profiles during electrochemical machining of alloys with the heterogeneous structure. Results of computer simulation and an analysis of the effects of various ECM factors and the structure of the workpiece material, on the of surface roughness and its parameters is done. The experimental investigations confirmed the effect of hydrodynamic instability of boundary layer on micro topography of machined surface done. © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.


Kozak J.,Institute of Advanced Manufacturing Technology | Zybura-Skrabalak M.,Institute of Advanced Manufacturing Technology | Skrabalak G.,Institute of Advanced Manufacturing Technology
Procedia CIRP | Year: 2016

The paper reports the development of a new Abrasive Electrical Discharge Grinding (AEDG) system and investigations of performance characteristic of machining difficult-to-cut materials. Developed machining system allows to perform following machining processes: conventional grinding, AEDG process and conventional grinding with in-situ EDM grinding wheel dressing. The first section of this paper describes thermal model to analyze the self-dressing phenomenon in AEDG. In the second part, the modular abrasive-electro-discharge grinding machine with adaptive control system is presented. There are also presented basic performance characteristics of the machining system achieved during machining of cutting tools made of PCD compacts sintered on WC base. Presented machining system MESO 25 CNC allows performance of all operations needed for production or regeneration of cutting tools with complex geometries. It is worth to notice that operations of rough and finishing machining can be performed with the machining system using single clamping. © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.


Skrabalak G.,Institute of Advanced Manufacturing Technology | Stwora A.,Institute of Advanced Manufacturing Technology
Procedia CIRP | Year: 2016

According to the rapid development of new materials, and requirements of the industrial sector towards effective and efficient machining of holes with diameters smaller than 1 mm, recent researches in the field of machining processes are aimed at investigations and optimization machining processes using multiple tools, multi-electrodes. Effective methods of machining difficult to cut materials are non-contact machining methods of electrochemical (ECM), electrodischarge (EDM) and hybrid electrochemical-discharge machining (ECDM). Both processes incorporating electrochemical dissolution, characterise with high material removal rates. They also do not induce high electrode wear ratios. In this paper, the results of experiments in the field of ECM, EDM and ECDM machining processes using batch electrodes will be presented. Batch electrodes used in the presented study consist of 9 square working tips of 2x2 mm, enabling flushing of the electrolyte through the electrode tip. Electrodes are prepared using additive manufacturing method - Selective Laser Sintering (SLS). The paper focuses on performance characteristics of machining processes for various materials used in the aircraft and plastic industry. There is also discussed (basing on the experimental results) influence of the working media supply method to the machining area (submerged or flushing) on the: machining accuracy, material removal rate and influence of stray currents on the surface of machined material. In the paper there is also presented comparison of results of various methods of contactless machining with tool electrodes prepared of using subtractive and additive manufacturing method. The comparison concerns machining time, machining accuracy and time necessary for manufacturing of tool electrodes. © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.


Skrabalak G.,Institute of Advanced Manufacturing Technology | Kozak J.,Institute of Advanced Manufacturing Technology
AIP Conference Proceedings | Year: 2011

Paper presents mathematical modeling and practical application of Dry Electrical Discharge Milling (DEDM) process using compressed air as dielectric. A comparison of this machining method with kerosene - based EDM milling is presented. The reported results refer to the experiments on micro - machining with thick - walled electrodes. The advantages and drawbacks of this machining method, within the field of micro-machining are described and discussed. © 2011 American Institute of Physics.


Spadlo S.,Kielce University of Technology | Kozak J.,Institute of Advanced Manufacturing Technology | Mlynarczy P.,Kielce University of Technology
Procedia CIRP | Year: 2013

In the paper, a comprehensive study of the electro-discharge mechanical alloying with using brush electrode is presented. This kind of a novel method is denoted as BEDMA (Brush Electro-Discharge Mechanical Alloying) and it combines features of electrical discharge machining with thermo-mechanical treatment. Electrode is being made of material which is to be alloyed on the part surface. A mathematical modelling of the thermal processes and mechanical action during the interaction of a single filament on the machined surface have been developed and used to estimation of the material transfer rate. © 2013 The Authors.

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