Wei Pengfei
Zhuzhou Zhike Institute of Science and Technology Service Co., Ltd.
Abstract：
To address the contradiction between surface wear resistance and overall toughness of traditional integral roller rings in heavy-load rolling and industrial friction working conditions, a WC cemented carbide outer ring/ferrous powder core composite roller ring was fabricated via integrated powder metallurgy forming technology in this study. The integrated forming process of layered powder filling, pre-compaction integral molding and vacuum liquid-phase sintering was adopted to realize one-step composite preparation of hard outer layer and tough inner core without subsequent welding and assembly procedures. The microstructure evolution, elemental diffusion behavior, interfacial phase composition and mechanical bonding properties of the composite interface were systematically characterized and analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and mechanical performance tests. The results show that under optimized sintering parameters (sintering temperature of 1280 ℃, holding time of 40 min and vacuum degree of 8×10-3 Pa), a dense and defect-free metallurgical bonding interface is formed between WC cemented carbide and ferrous matrix. A uniform interfacial transition layer with a thickness of 8–12 μm is generated through the interdiffusion of W, C, Fe and Co elements, and new interfacial reinforcement phases such as Fe2W3C are uniformly precipitated, which effectively eliminates interface voids and crack defects. Mechanical test results indicate that the interfacial shear bonding strength reaches 386 MPa, and the composite roller ring integrates the high hardness (1480 HV) and excellent wear resistance of WC cemented carbide outer ring with the high toughness and impact resistance of ferrous core material. This integrated powder metallurgy forming technology avoids interface failure risks caused by traditional secondary processing, and provides a low-cost, high-integrity preparation method for high-performance composite roller ring components, which has broad application prospects in metallurgical rolling, mechanical transmission and heavy-duty equipment fields.
Key Words：
powder metallurgy integrated forming; WC cemented carbide; ferrous powder core; composite roller ring; interfacial bonding characteristics; elemental diffusion
