以平均粒径约为30μm,空心球壁厚约1.8μm的空心球结构WC-6Co复合粉为原料,利用放电等离子烧结(SPS)技术制得不同烧结温度、保温时间、烧结压力工艺下的WC-6Co硬质合金.采用扫描电镜、钴磁仪等检测手段对合金的组织与性能进行表征分析.结果表明:随着烧结温度的升高,合金的致密度和硬度升高;在实验范围内合金密度与硬度随着保温时间的延长而增加,再趋于稳定;烧结压力对合金密度、硬度等性能影响不大.综合考虑合金性能,较好烧结工艺为:温度1 250℃、保温时间5 min、烧结压力50 MPa.该烧结工艺制得的合金的密度达14.69 g/cm3、断裂韧性达12.23 MPa·m1/2,其组织也很细很均匀.
WC-6C0 cemented carbide were prepared by spark plasma sintering ( SPS) at different sintering temperatures, holding times and sintering pressures with WC-6C0 composite powders, whose average particle sizes are scaled about 30 (xm and hollow spherical wall thickness 1.8 | JLm , as raw materials. The organization and properties of the alloy are characterized by SEM and cobalt magnetic. The results show that the density and hardness of the alloy increase with the rising sintering temperature. The density and hardness of the alloy increases with the prolonging holding time, and then tends to be stable. Sintering pressure has little effect on the properties of the alloy. The optimal sintering process is sintered at 1 250 °C for 5 min under 50 MPa. The density of the alloy prepared by the optimum sintering process is 14.69 g/ cm3 and the fracture toughness is 12.23 MPa *m1/2 with fine and uniform microstructure.