Characterization of the MC Carbides and Mechanical Properties in a TiC Particles-Strengthened Cobalt-Based Alloy through HIP, Solid-Solution and Aging Treatments

Abstract

In previous studies, we mixed and added different amounts of TiC powders (0, 10, 15 and 20 mass%) to the cobalt-based alloy powders. The results showed that adding 15 mass% TiC powder to the cobalt-based alloy and sintering at 1280°C for 1 h was the optimal process. The aim of this paper is continue exploring a series of HIPing processes and various heat treatments for T0 and T15 composite materials, and examining the effects on the microstructure and mechanical properties of TiC particles-strengthened cobalt-based alloy. The experimental results showed that the highest TRS value of 1566.7 MPa was obtained by the 15 mass% TiC additive powders, which was sintered at 1280°C for 1 h, followed by HIP plus solid-solution heat treatment. The experiment proved that the closed pores can be effectively eliminated (1.34% → 0.69%) by HIP treatment. In addition, the more uniform precipitation of M₆C carbides appeared in the grain-boundary and matrix after aging treatment. Moreover, the added amounts of TiC powder play an important role in improving the mechanical properties of cobalt-based alloy.