Application of U-FAST Technology in Sintering of Submicron WC-Co Carbides

This work presents the microstructure, hardness, fracture toughness coefficient KIC and phase composition of submicron WC-4Co carbides. The carbides were sintered using the innovative U-FAST (Upgraded Field Assisted Sintering Technology) method, from mixtures of WC-Co powders with an average WC grain size of 0.4 µm and 0.8 µm. The obtained sinters were characterized by a relative density above 99% of the theoretical density. The hardness of the obtained composites was above 2000 HV30, while the KIC coefficient was about 8 MPa m1/2.

本研究系统表征了亚微米WC（碳化钨）-4Co硬质合金的显微组织、硬度、断裂韧性系数KIC与物相组成。该类硬质合金以平均WC晶粒尺寸分别为0.4 μm和0.8 μm的WC-Co混合粉末为原料，采用创新性U-FAST（升级型场辅助烧结技术，Upgraded Field Assisted Sintering Technology）工艺完成烧结。所得烧结体的相对密度高于理论密度的99%。所制备的复合材料硬度高于2000 HV30，其断裂韧性系数KIC约为8 MPa·m^(1/2)。