Effect of Deep Cryogenic Treatment on Machinability of NiTi Shape Memory Alloys in Electro Discharge Machining

Abstract:

NiTi shape memory alloys usually consist of binary alloys of nickel and titanium concentrations near the equiatomic composition. Due to high hardness of NiTi alloys, the traditional machining processes are not able to machine these alloys. Nontraditional processes like electro discharge machining (EDM) ; due to their unique mechanism of material removal are useful alternatives in such case.The overall machining performance of electro discharge machining process depends on the electrical, thermal properties of both tool and workpiece materials. Cryogenic treatment has a history of improving mechanical, electrical, and thermal properties of materials. Recently, very few researchers applied cryogenic cooling and treatment of workpiece and tool in conventional EDM and found notable improvement in machining performance. In this study, NiTi shape memory alloys was subjected to around-185C for cryogenic treatment and the effects of cryogenic treatments on the machiniability of NiTi shape memory alloys workpieces in electro discharge machining have been investigated. The electrical conductivity of workpiece exceptionally improved. Experimental results showed about 19% increase in material removal rate of cryogenic treated workpieces. Variations in tool wear rate was found to be marginal.

• Periodical: Applied Mechanics and Materials (Volumes 592-594)
• Pages: 197-201
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.592-594.197
• Online since: July 2014
• Authors: Vijaykumar S. Jatti*, T.P. Singh
• Keywords: Deep Cryogenic Treatment, Material Removal Rate (MRR), NiTi Shape Memory Alloys, Tool Wear Rate

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