纳米Al_2O_3-硬质合金复合材料试验研究

Experimental Research on the Composite Material of Nano-Al_2O_3/Cemented Carbide

基于在WC-Co基体中加入纳米Al2O3强化硬质合金性能的设想,对几种配方的纳米Al2O3-硬质合金复合材料进行了力学性能测试、耐磨耐冲击试验和微观组织结构的分析研究。结果表明,加入适量的纳米Al2O3不但可细化合金晶粒,使材料组织结构更加均匀,耐磨性能提高,而且增强了WC晶界的强度,使得材料的断裂形式由沿晶断裂转向穿晶断裂,起到增强补韧的作用。同时,加入稀土也提高了材料的综合性能。将纳米复合材料制成钻齿并装配成钻头进行了现场试验,与硬质合金齿钻头相比,其破岩效率提高20%,使用寿命提高80%。

Adding nano-Al2O3 into WC-Co substrate may be useful to enhance the performance of cemented carbides.Based on the above view,the mechanical properties,wear and shock resistance,and microstructure of the composite material of nano-Al2O3/cemented carbide with different formula were investigated.The results show that adding proper nano-Al2O3 not only refines alloy grains,and improves microstructure uniformity and wear resistance of the composite material,but also enhances the strength of WC grain boundary,which plays a role of strengthening and toughening and results in fracture form shift from intergranular fracture to transgranular fracture of the composite material.Meanwhile,adding rare earth also improves the comprehensive performance of the composite material.Drill teeth made with the nano-composite materials are assembled into a drill bit that is then tested in situ.Compared with the drill bit assembled with cemented carbide drill teeth,the above drill bit is of 20% higher rock breaking efficiency and 80% longer service life.