Improvement of the Machinability of Ti-6Al-4V Alloy Wire Electro Discharge Machining with Cryogenic Treatment

Titanium alloys are well known with their superior properties such as corrosion resistance, specific strength; however, machining and shaping of this material are quite tricky and costly. In the present study, an attempt was made to improve the machinability of Ti-6Al-4V alloy by conducting deep and shallow cryogenic treatment. For this purpose grade, 5 in ASTM B348 titanium alloy was supplied as bar material. Cryogenic treatment was conducted to both annealed and aged state Ti-6Al-4V alloy. Machinability of different heat-treated materials was tested by using a CNC wire electro discharge machining machine. The test results were evaluated by material removal rate, surface roughness and surface hardness of the machined surface. Additionally, the electrical conductivity of different heat-treated specimens was measured. An XRD test was conducted to understand the internal changes happened with the effect of heat treatment. The results of the study show that the application of cryogenic treatment to both annealed and aged samples improved the machinability and electrical conductivity and provides better surface roughness of machined surfaces. This study suggests an alternative approach to improve the machinability of Ti-6Al-4V alloy and presents a characterization study about the effect of cryogenic treatment on Ti-6Al-4V alloy. Graphic