Metal injection moulding of nickel-based superalloy CM247LC*

Metal injection moulding (MIM) is a promising new production technology for small- to medium-sized parts with high complexity for high-temperature applications like aero engines or turbochargers. This study concerns the feasibility of manufacturing parts from nickel-based superalloy CM247LC via MIM. CM247LC poses a serious challenge for MIM processing. Because of its high aluminium content, the strength potential is very high, but the sintering capability is severely restricted. Differential scanning calorimetry and dilatometry measurements as well as ThermoCalc simulations are used to optimise the sintering step of the MIM process route. Carbon, nitrogen and oxygen contents of the powder and the as-sintered specimens are measured to evaluate the pick-up of impurities during processing. The microstructure of the as-sintered specimens is characterised with respect to residual porosity, grain size, carbide content and gamma' precipitation size and morphology. Ways to further improve the microstructure and strength will be discussed.