WC/W2CP表面改性对WC/W2CP-NiCrBSi/耐热钢复合材料磨损性能的影响

Effect of Surface-Modified WC/W2CP on Wear Behavior of WC/W2CP-NiCrBSi/Refractory Steel Composite

摘要:

以铸造碳化钨（WC/W2CP）为增强颗粒，利用真空熔烧工艺制备了一种结构增韧的金属基复合材料。利用SEM，EDS，显微硬度测试和图像分析等手段研究了WC/W2CP表面改性前、后复合材料中颗粒增强区域（WC/W2CP-NiCrBSi）的微观组织结构和性能；利用环-盘式磨损试验机研究了WC/W2CP表面改性对复合材料在室温和600 ℃时的磨料磨损性能的影响。结果表明，经表面改性后WC/W2CP在NiCrBSi基体中的分解得到了有效抑制，颗粒内部WC/W2C共晶组织的含量与未改性的颗粒相比提高了1.6倍。以表面改性的WC/W2CP为增强颗粒能显著降低复合材料在室温和高温时的磨损率。在600 ℃时磨损表面形成了层状结构的保护膜，致使复合材料的磨损率低于室温时的磨损率。

Abstract:

A structurally toughened metal matrix composite reinforced by cast tungsten carbide particles (WC/W2CP) was fabricated by vacuum fusion sintering. Microstructure and properties of the particle-reinforced regions (WC/W2CP-NiCrBSi) in the composite reinforced by primary and modified WC/W2CP were investigated by SEM, EDS, microhardness testing and image analyzing. Effects of the surface-modified WC/W2CP on the wear behavior of the composite were estimated on a ring-disc wear tester at room temperature and 600 °C. The results show that the dissolution of surface-modified WC/W2CP is effectively restrained and the content of the residual WC/W2C eutectic in particle is 2.6 times of the primary WC/W2CP. The wear rate of the composite reinforced by modified WC/W2CP decreases significantly compared with the composite reinforced by primary WC/W2CP at room temperature and 600 °C. The laminated structure self-protecting layers are formed on the worn surface of the composite at 600 °C, resulting in a lower wear rate than that at room temperature.