钴含量对粗晶硬质合金磨损性能的影响

Effect of cobalt content on wear behavior of coarse-grained hardmetals

粗晶WC-Co硬质合金作为新型矿用工具材料,在不同工况条件下的耐磨性能与失效行为对其工业应用具有重要影响。本研究以Si C颗粒为磨料,采用MLD-10型动载磨粒磨损试验机,研究钴含量对WC晶粒度为5μm的粗晶硬质合金冲击磨粒磨损性能的影响。实验结果表明：钴的质量分数在6%~14%范围内增加时,硬质合金的磨损系数K均呈线性增加,耐冲击磨粒磨损性能则呈线性降低。粗晶硬质合金的耐冲击磨粒磨损机制为：表面层的钴粘结相先被Si C颗粒磨损,然后合金的耐磨性主要取决于凸出WC颗粒的失效行为。因此,硬质合金的磨损系数K与WC硬质相的体积含量呈正比。

Coarse-grained WC-Co cemented carbides are used as a new type materials of mining tool and its wear property need to be understood. The effect of cobalt content on wear behavior of coarse grain cemented carbides, whose WC grain size was around 5gm, was investigated by MLD-10-type dynamic load abrasive wear testing machine. The testing results show that with the cobalt mass fraction increasing from 6% to 14%, the wear coefficient K of coarse grain cemented carbides increases linearly and the wear resistance decreases linearly. The impact-abrasion mechanism of coarse grain cemented carbides is that the surface cobalt binder is abrased by SiC abrasives and then the wear resistance of hardmetal mainly undertaken by prominent WC grains, so the wear coefficient K of cemented carbides is directly proportional to the volume fraction of the WC hard phase.