硬质合金颗粒增强铁基复合材料的三体磨料磨损性能

Three-Body Abrasive Wear Behavior of Iron Matrix Composite Reinforced with Cemented Carbide Particles

以回收的钨钴钛类硬质合金为增强颗粒,采用负压铸渗工艺制备了颗粒增强高铬铸铁基复合材料,并借助于金相分析和X射线衍射等手段研究了复合材料的微观界面.由于铸渗过程中增强颗粒的部分熔解及W、C、Co和Fe等元素的扩散,在界面处产生了Fe3W3C、Co3W3C等化合物,形成了明显的过渡层,从而确保了增强颗粒与基体之间为冶金结合.利用三体磨料磨损试验机研究了复合材料的磨损性能,结果表明:磨损过程分为4个阶段,复合材料的体积磨损量随着磨损试验的进行先下降后上升,其中在第3阶段达到最低值;复合材料的体积磨损量随着磨料粒度增大而逐渐增加.将制备的复合材料同工程中常用的热处理态高铬铸铁以及WC颗粒增强高铬铸铁基复合材料进行了耐磨性对比,发现其体积磨损量显著低于高铬铸铁,而与WC颗粒增强高铬铸铁基复合材料差别不大,显示出优异的性能价格比.

The high-Cr white cast iron （WCI） matrix composite reinforced with recovered cemented carbide （CC） particles was prepared by the vacuum infiltration casting process. The interracial structure between CC particle and the iron matrix was analyzed with optical microscope and X-ray diffraction （XRD）. Owing to partial dissolution of the CC particles and diffusion of the elements such as W, C, Co and Fe, the compounds such as Fe3W3C and Co3W3C were formed in the interface, which ensured metallurgical bonding in the interface. The wear behavior of the fabricated composite was investigated on the three-body abrasive wear tester. The results show that the test included four stages, the worn volume of the composite decreased firstly until reached the minimum at the third stage, then increased, and the worn volume increased with the increase of abrasive particle size. Compared with the heat-treated high-Cr WCI and the WC/high-Cr WCI composite, the worn volume of the fabricated composite was much lower than the former, but did not significantly differ from the later.