SPS烧结制备WC-6Co-1.5Al硬质合金的研究

Research on WC-6Co-1.5Al hardmetals prepared by spark plasma sintering

针对WC-6Co-1.5Al球磨粉末,研究SPS烧结工艺对烧结合金密度、组织、力学性能及断口形貌的影响规律。研究结果表明:在脉冲电流基值为360A、峰值为3 000A、频率为50Hz、占空比为50%,恒流电流为1 500A,总烧结时长为6min,烧结压力为30MPa的工艺参数下,利用脉冲电流烧结1min后,继之以恒流电流烧结5min,可获得密度、硬度和弯曲强度分别达14.2g/cm3、94HRA和1 660MPa的超细晶WC-6Co-1.5Al硬质合金块体材料;进一步延长或缩短脉冲电流烧结时间,烧结体的密度、硬度和弯曲强度反而下降。

WC-6Co-1.5Al （wt % ） hardmetals were successfully fabricated from elemental mixed powders by high energy milling and spark plasma sintering. Influences of pulse electrical current sintering time on the density, microstructure, mechanical properties and bend fracture morphologies of the sintered alloys were also studied. Results show that after being sintered for lmin by pulse electrical current, then followed by constant electrical current for 5min, the ultra-fineWC-6Co-1.5Al hard materials with the density of 14.2g/cm^3, hardness of 94HRA and bend toughness of 1660MPa were produced under a pressure of 30MPa. The peak and base pulse electric current, frequency and duty ratio was 3000A, 360A, 50Hz and 50%, respectively, and the constant electric current was 1500A. With prolonged or shortened pulse electrical current sintering time, the density, hardness and bend toughness of the sintered materials decreased.