采用等离子球磨技术制得W-C-10Co-0.9VC-0.3Cr3C2纳米复合粉体,并利用单向模压成型法将其压制成生坯,再经低压烧结一步法制备成硬质合金.研究表明,等离子球磨3 h所获得的复合粉体呈片层状形貌,并且成分分布均匀.在1 380 ℃及1 400 ℃烧结时,由于等离子球磨的特殊作用,VC、Cr3C2对WC晶粒长大抑制作用突显.1 380 ℃烧结制备的硬质合金,致密度为99.2％,WC平均晶粒尺寸为250 nm,硬度和横向断裂强度分别为92.3HRA和2 443 MPa,具有最佳的WC晶粒尺寸与致密度配合,以及最佳的综合力学性能.%W-C-10Co-0.9VC-0.3Cr3C2 nano composite powders were prepared by plasma milling(P-milling),and subsequently compressed into green compacts with a uniaxial pressure,then the green compacts were carbonized and sintered in a one-step me-thod by low pressure sintering technology.The analysis results indicate that the homogeneous and lamellar structure composite powder is achieved by P-milling for 3 h.Due to the special effect of P-milling,VC and Cr3C2 begin to play a role of inhibition to WC grain size at the temperature of 1 380 ℃ and 1 400 ℃.Among them,the hard metals that sintered at 1 380 ℃ exhibit the optimum combination of WC grain size and relative density,and the best mechanical performance simultaneously.The density of hard metal is 99.2％with 250 nm of mean WC grain size,and the hardness and transverse rupture strength reach up to 92.3HRA and 2 443 MPa,respectively.
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