Author : R.G.Deshpande 1
Date of Publication :17th May 2017
Abstract: Productivity of cutting tool inserts in machining high strength and high temperature resistance alloys is an issue of concern. This drawback persists in case of Sintered carbides also, that have machining capabilities comparable with HSS and Cast Steel alloys. Many innovative methods have been implemented in this regard, out of which cryogenic treatment appears to be a promising technique. In this technique tool inserts are soaked in a controlled atmosphere at beyond -150 0C for predetermined time and brought back to room temperature. This treatment normally leads to contraction of metal structure increasing hardness and related properties. In the present work untreated Tungsten carbide tool inserts have been subjected to Cryogenic treatment at -193 0C followed by tempering cycle to relieve stresses formed during cooling. The treated samples showed improved hardness and tool life when subjected to machining tests at different cutting velocities. The microstructure study showed the formation of complex carbide phases and further studies revealed the increased population of carbides and cobalt binder which have contributed towards improvement in properties.
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