Effects of graphite powder and Mo₂C particles on the densification behavior and mechanical properties of 10Cr15CoMoV powder sintering

To address the issue of insufficient density in 10Cr15CoMoV powder during sintering, this study systematically investigated the effects of incorporating varying amounts of graphite (0–0.9 wt%) and Mo₂C (0–6 wt%) particles into the powder on its densification behavior, microstructural evolution, and mechanical properties, based on the super-liquid-phase sintering (SLPS) method. Results indicate that graphite addition transforms the original Cr 22.23 Fe 0.77 C 6 phase into Fe 7 C 3 and Cr 7 C 3 , whilst the synergistic addition of graphite/Mo₂C promotes the precipitation of both Fe 7 C 3 , Cr 7 C 3 and Fe 2 Mo 4 C phases. Additionally, compared to the original powder, the densification temperature for the 10Cr15CoMoV powder containing 0.6 wt% graphite and 6 wt% Mo₂C has been reduced from 1450 °C to 1275 °C, representing a decrease of approximately 12 %. The hardness increased from 586 HV to 819 HV after densification, marking an enhancement of 39.8 %, with a flexural strength of 1366 MPa. Concurrently, the fracture mechanism shifted from predominantly intergranular to a quasi-cleavage-dominated mode, with supplementary intergranular features. • Reduced sintering temperature and enhanced powder densification. • Controlled carbide phase regulation and modified microstructure. • Particle addition induced transition in fracture mechanism.