Microstructures and Mechanical Properties of the TiC/CM247LC Nickel-Based Composite Fabricated by Selective Laser Melting: Effect of Heat Treatment

In this study, TiC/CM247LC nickel-based composite was successfully prepared by selective laser melting, then was heat treated at a solid solution temperature of 1260 degrees C and different aging temperature of 840 degrees C, 870 degrees C, 900 degrees C and 930 degrees C respectively. Effects of aging temperatures on the microstructures and mechanical properties were systematically studied. The results show that the microstructures of all the heat treated samples are composed of gamma matrix, carbides and gamma ' phase. The gamma grains remain a columnar shape after treatments, but the size of gamma ' phase grows up gradually with the increasing aging temperature. The composite treated at an aging temperature of 870 degrees C exhibits the best mechanical properties with the tensile strength of 1073 MPa, yield strength of 1004 MPa and elongation of 7.57%. The plastic deformation and strengthening mechanisms of heat treated composite were systematically investigated.