AlCoCrFeNi2.1粘结剂对WC-HEA硬质合金组织与性能的影响

    Effect of AlCoCrFeNi2.1 Binder on Microstructure and Properties of WC-HEA Cemented Carbide

    • 摘要: 针对WC-Co硬质合金刀具材料中Co粘结剂成本高的问题,采用放电等离子烧结技术制备了AlCoCrFeNi2.1高熵合金(high entropy alloy,HEA)粘结剂含量为5%~20%的WC-HEA硬质合金,分析了不同粘结剂含量的WC-HEA硬质合金的微观组织、物相组成、硬度和断裂韧性等力学性能,探讨了用AlCoCrFeNi2.1合金粉末代替Co粉制造WC硬质合金的可行性。结果表明:WC-HEA硬质合金组织由WC和HEA固溶体两相组成,WC相平均晶粒尺寸在0.23~0.48 μm。随着AlCoCrFeNi2.1粘结剂含量的增加,WC-HEA硬质合金的硬度、断裂韧性均呈先升高后降低的趋势。WC-15%HEA硬质合金中小于0.2 μm 的超细晶WC晶粒最多,WC平均晶粒尺寸仅为0.23 μm,强韧性匹配最好,硬度为1965 HV,断裂韧性KIC值为13.6 MPa·m1/2

       

      Abstract: Aiming at the problem of high cost of Co binder in WC-Co cemented carbide tool materials, WC-HEA cemented carbides with 5%-20% of AlCoCrFeNi2.1 high entropy alloy binder were prepared by spark plasma sintering (SPS). The microstructure, phase, hardness, fracture toughness and density were tested and analyzed. The feasibility of using AlCoCrFeNi2.1 alloy powder instead of Co powder binder to manufacture WC cemented carbide was discussed. The results show that the microstructure of WC-HEA cemented carbide is composed of two phases of WC and HEA solid solution, and the average grain size of WC phase is 0.23-0.48 μm. With the increase of AlCoCrFeNi2.1 binder content, the hardness of WC-HEA cemented carbide increases firstly then decreases, and the fracture toughness improves. The ultrafine-grained WC grains in WC-15% HEA less than 0.2 μm are the most, the average grain size of WC is only 0.23 μm, and the strength and toughness match is the best, the hardness is 1965 HV and the fracture toughness KIC value is 13.6 MPa·m1/2.

       

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