Investigation of the effects of engagement movements and feeds on tool wear when milling of titanium alloys with female

It is known that the Ti6Al4V alloy has poor machinability properties but it is widely used in aircraft, biomedical, chemical, and marine and food industry because of their good yield strength to density ratio and high thermal, corrosion strength. The aim of the present study is to obtain optimum cutting parameters of Ti6Al4V alloy by investigating effects of engagement movement type and feed rate on tool wear when pocket milling. In the research, first two different heat treatment was applied to test specimens in shuttle kiln to obtain effects of the β-phase ratio in microstructure to machinability of Ti6Al4V alloy. The test specimens in first group heat threatened at 955°C for one hour and water quenched than heat threatened at 550°C for four hours and air-cooling was performed. The specimens in second group heat threatened at 955°Cfor four hour and then cooled in furnace. CNC router was used to perform machinability tests with three different engage movement type as helical, plunge and ramp on part and three different feed rate as 366, 732 and 1095 mmpmin. AlTiCrN coated Ø4mm micro grain solid carbide milling tools were used for tests. Surface roughness and tool wear were determined as performance criteria. The test results showed that increasing β-phase in microstructure increases the both hardness and machinability, increasing feed rate increases the surface roughness and decreases the tool life, plunge engagement movement type gives the optimum results for all condition when the helical gives best results using low feed rates.