(04)Influence of Heat Treatment on Microstructure and Mechanical Properties of IN713LC Fabricated by Metal Injection Molding (MIM)

摘要

Metal injection molding (MIM) is a promising new production technology for small to medium sized parts for aeroengine applications. This study is focused on Ni-based Inconel 713 low carbon (IN 713LC). "As sintered" as well as "as sintered and heat treated" MIM IN 713LC is characterized by carbide precipitates outlining prior particle boundaries (PPBs), distributed y' precipitations in the grain interior and some minor residual porosity. The carbon content is significantly higher than in the starting powder, but still within the range of the IN 713C specification. In this study two different heat treatments are investigated in order to optimize the microstructure and the mechanical performance of MIM IN 713LC. Appropriate temperatures for the heat treatments are derived from the evaluation of differential scanning calorimetry (DSC) measurements. Homogenization and significant refinement of the y' precipitations can be realized by appropriate heat treatment. Accordingly, tensile strength of the heat treated material is superior.