Turning of advanced Ni based alloys obtained via powder metallurgy route

Nickel based alloys (RR_X) manufactured via powder route are considered the next generation materials that can offer increased efficiency of gas turbine engines. Their chemistry and mechanical properties indicate even lower machinability than the current disc alloys. The paper reports on specifics when rough and finish turning these new Ni based alloys. Tool life, surface finish, workpiece surface integrity and residual stress distributions have been used as multi-objective quality criteria to assess the capability of shaping RR_X alloys. The optimised cutting parameters/route was then employed to produce surfaces in low cycle fatigue samples to demonstrate machining capability to Airworthiness Authorities.