This study systematically investigated the effects of electric current aging treatment (EAT) temperature (800–950°C) and duration (1–20 min) on the microstructural evolution and mechanical properties of Co-Cr-Mo alloys. Microstructural analysis revealed that the EAT at 800–950°C for 5 min promotes the precipitation of the ε-Co phase and the growth of carbides (M 23 C 6 and M 6 C). At 950°C, the carbide size and volume fraction increased significantly, reaching 8.9 μ m and 6.8 vol.%, respectively. Notably, a lamellar microstructure comprising ε-Co and M 23 C 6 carbides started to form at 850°C, and the prolonged durations (1 − 20 min) led to a progressive increase in the carbide size and volume fraction. Additionally, the formation of carbides increased the strength of alloys, but it was not conducive to plasticity. The samples treated at 850°C for 1 min exhibited exceptional ultimate tensile strength (830 MPa) and ductility (12.9%), significantly exceeding the performance of some alloys treated by conventional aging methods. These findings demonstrate that EAT is a rapid and effective approach for optimizing the microstructure and mechanical properties of Co-Cr-Mo alloys.
Cheng et al. (Thu,) studied this question.