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Comparative Analysis of Different WEDM Strategies Applied to Cut WC-Co Cemented Carbides

Poroś Dariusz

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 4

126--135

EN

Cemented carbides WC-Co feature high mechanical properties and outstanding wear resistance. Traditional grinding of such hard workpiece features low material removal rate and diminished tool life. Notwithstanding that, even if, proper cooling fluid is applied; abrasive machining of cemented carbides characterizes poor efficiency. The aim of this study was to investigate the issue of WEDM of the cemented carbides WC-Co with two alternative materials of the wire electrodes applied. The presented experimental surface layer geometry measurements was carried out on a modern profilometer MITUTOYO SV 3200. Especially, WEDM results with wire flushing and in immersion were compared. Investigated were the effects of such input parameters as the pulse width and the time between two pulses on the output parameters such as area cutting efficiency, workpiece surface roughness in 2D and 3D. Analysing SEM microphotographs the surface layer defects after WEDM, cobalt depletion and pitting was discoursed. The analysed results provided WEDM of WC-Co cemented carbides with molybdenum wire electrode as seventy one percent less efficient and higher roughness was obtained for the same number of passes. The lowest height of the roughness on the surface after cutting with molybdenum wire amounted to Ra and Sa = 3.5 μm. Such roughness involves a 25 μm deep undesirable heat affected zone. WEDM with equal number of passes and brass wire resulted in roughness Ra and Sa =0,9 μm. In further research, an endeavour should be directed to examine different water and hydrocarbons derivative dielectrics impact on the surface layer structure and chemical composition of the machined WC-Co carbides.

2

Comparative analysis of WEDM with different wire electrodes applied to cut titanium Ti6Al4V

Poros Dariusz, Wisniewska Magdalena, Zaborski Stanislaw

Journal of Machine Engineering

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2020

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Vol. 20, No. 4

116--125

EN

The machining of titanium alloys by traditional methods causes many disadvantages of both technical and economic nature. These materials are characterized by very low thermal conductivity and belong to hard to machine materials. When machining these materials with conventional methods, there is a problem of chips thermal softening and increased tool wear. During machining, e.g. milling despite intensive cooling, the performance achieved is low. Although traditional processes of titanium alloys treatment pose many problems, the use of this strong and lightweight materials is still evolving. The aim of this article was to present the issue of wire electrical discharge machining of Titanium alloy Ti6Al4V. In particular, the comparison of brass wire and non-consumable molybdenum electrode and flushing techniques were analyzed. The relationship between the overheating of the machined surface layer and the magnitude of stresses and the formation of micro cracks on the machined surface was discussed. Based on its own research and the presented analysis of the literature on the subject, future directions of further research were indicated. An attempt should be made to investigate how flushing efficiency affects the machined shape, structural changes and chemical composition of the titanium alloy’s surface layer.

3

Effect of process parameters on the condition of the wire electrode in WEDM of Ti6Al4V

Zaborski S., Poroś D.

Journal of Machine Engineering

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2008

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Vol. 8, No. 2

52--64

EN

Conventional machining of titanium alloy Ti6Al4V cause high temperature and rapid wear of tool which makes him hardly suitable for machining by machine cutting. The presented experimental study was carried out on a modern wire EDM Sodick AQ327L. Three types of the wire were used. Investigated were the effects of such input parameters as the pulse width and the time between two pulses on the output parameters such as area cutting efficiency, workpiece surface roughness and wear rate of the electrode. The resulting relationships were determined using the conventional regression analysis and neural networks. The results were checked for goodness of fit.