以水溶液化学法制备的WC-6％Co纳米复合粉体为原料,利用放电等离子烧结(spark plasma singtering,SPS)技术制备了超细硬质合金.研究了烧结温度对硬质合金显微组织和力学性能的影响,分析了纳米粉体烧结的致密化过程.结果表明:随着烧结温度的升高,烧结致密性、硬度和断裂韧性都呈现先增加后降低的变化趋势,在升温速度为100℃/min,烧结温度为1 250℃,保温时间5 min,压力为30 MPa的工艺条件下,利用SPS技术可制备综合力学性能良好的超细晶硬质合金,平均晶粒大小为420 nm,维氏硬度为1 969 HV30,断裂韧性为10.7 MPa·m1/2.“,”Using nanocrystalline WC-6％Co composite powder produced by aqueous solution chemistry method as raw material,ultrafine cemented carbide was prepared by spark plasma singtering (SPS) technology.The influence of sintering temperature on micostructure and mechanical properties of the cemented carbide was studied,and the densification process of powder was analyzed.The results show that sintering densification,hardness and fracture toughness are increased first and then decreased with the increase of sintering temperature.Under the condition that heating speed is 100 ℃/min,sintering temperature is 1 250 ℃,holding time is 5 min and pressure is 30 MPa,the ultrafine cemented carbide with good mechanical properties is prepared by SPS technology,the average grain size is 420 nm,the hardness is 1 969 HV30 and the fracture toughness is 10.7 MPa·m1/2.