铝掺杂WC-Co基硬质合金的高温摩擦学性能、磨损机理及抗氧化性能研究

通过高能球磨和电火花等离子烧结，成功制备了(xAl-WC)-6Co(x=0.2，0.33)三元复合材料，并研究了铝掺杂WC-Co基硬质合金在空气环境中500、600和700 ℃下的摩擦学性能. 所制备的铝掺杂WC-Co，基体由WC和Co耦合而成，Al在烧结过程中发生氧化，基体上弥散分布细小的Cr₃C₂和Al₂O₃增强相. (0.2Al-WC-6Co)的硬度与断裂韧性明显高于WC-6Co, (0.33Al-WC)-6Co的断裂韧性较低. 脆性钨类氧化物的形成是Al-WC-Co硬质合金高温磨损的主要原因. 随着Al元素加入量的提高，硬质合金的高温抗软化性能和抗氧化性能提高，磨损表面的剥落和破碎行为减弱，材料的高温耐磨性能提高. 

Wear Mechanism,Tribological and Anti-Oxidation Properties of Al Doped WC-Co Hardmetals under High Temperature

Combining high energy ball milling and spark plasma sintering (SPS) technologies, (x%Al-WC)-6%Co (x=0.2 or 0.33, atomic fraction) ternary composites were successfully prepared. The tribological properties of Al doped WC-Co at 500, 600 and 700 ℃ in air environment were studied. The matrix of the prepared Al doped WC-Co was coupled by WC and Co, and Al oxidized during the sintering process. Numerous fine Cr₃C₂ and Al₂O₃, as hard phases, dispersed in the matrix. The hardness and fracture toughness of the (0.2Al-WC-6Co) were higher than that of WC-6Co. (0.33Al-WC)-6Co showed low fracture toughness. The formation of brittle tungsten oxides was the main reason of wear loss of Al-WC-Co at high temperature. With the increasing contents of Al, both the high temperature softening resistance and oxidation resistance of the Al-WC-Co were improved, and the spalling and breaking behaviors on the worn surface were reduced. The addition of Al could led to the improvement of the tribological properties of WC hard alloy.