Metal Injection Molding of Nickel-Base Superalloy CM247LC: Influence of Heat Treatment on the Microstructure and Mechanical Properties

摘要

Metal Injection Molding (MIM) offers a cost effective near-net-shape production technology for small to medium sized parts with high geometrical complexity. High temperature applications like aero engines or turbochargers require high strength superalloys as materials which have not been a major subject of MIM so far. The present study concerns the microstructure and high temperature mechanical properties of nickel-base superalloy CM247LC after MIM processing. It is found that CM247LC can be sintered to a relative density of more than 98%. The pick-up of impurities like carbon can be kept low if suitable binders and clean furnace conditions are employed. The fine grain size of as sintered parts results in good room temperature mechanical properties, but the creep strength at high temperatures is relatively poor. By heat treatments designed to promote grain growth the creep strength could be considerably increased.