Microstructure and Mechanical Property of a Multi-Scale Carbide Reinforced Co–Cr–W Matrix Composites

Abstract

In order to meet the demand for high wear-resistant Co-based material used in fields such as aerospace, energy, medical, etc., this study attempts to improve the comprehensive performance of this material by adding some reinforced phases and adjusting the sintering temperature. Results indicate the pure Co–Cr–W alloy is composed of γ-Co, M29C, and M6C (Ni3W3C), and the Co–Cr–W matrix composites are composed of γ-Co, M29C, M6C (Co2W4C), M23C6, and WC. With increasing the hot-pressing sintering temperature, the element diffusion in the material becomes sufficient, and the microstructure of Co–Cr–W alloy and composites materials becomes denser. When the sintering temperature is over 1150 °C, the bending strength and the toughness of the Co–Cr–W matrix composites are higher than that of the pure Co–Cr–W alloys. The added reinforced phases help the composites to gain a multi-scale strengthening effect, which makes the composites have a more comprehensive performance. Our results emphasize the importance of added reinforced phases and help to optimize the preparing process in preparing the Co–Cr–W alloys.

Keywords

• Co–Cr–W alloy
• multi-scale carbide reinforcing
• powder metallurgy
• microstructure
• bending strength
• toughness