(华南理工大学 机械工程学院, 广州 510640)
摘 要: 采用脉冲频率为0、50和100 Hz的电流对高能球磨铁基粉末进行脉冲电流烧结, 并研究脉冲频率对粉末的致密化行为、烧结材料的显微组织和力学性能的影响。 结果表明, 通电烧结初期脉冲电流烧结样品的密度和硬度均高于直流电流烧结的试样, 但通电烧结后期使用脉冲电流与直流电流所烧结样品的密度和硬度差别不大； 相同烧结温度下不同脉冲频率烧结试样的横向断裂强度的相对大小为σ50 Hz>σ100 Hz>σ0 Hz； 当烧结温度为1 100 ℃时, 不同脉冲频率下所获得的烧结材料的显微组织没有显著差别。
关键字: 铁基粉末； 脉冲电流烧结； 脉冲频率； 显微组织；力学性能
（School of Mechanical Engineering, South China University of Technology,
Guangzhou 510640, China）
Abstract: The iron-based powders prepared by high-energy ball-milling were sintered by means of pulsed electric current sintering (PECS) at various pulse frequencies (0, 50 and 100 Hz). The effects of pulse frequency on the densification behavior of powder as well as the microstructure and mechanical properties of as-sintered specimen were investigated. The results show that during the initial sintering stage, the density and hardness of the specimen sintered with pulsed current are higher than those of the specimen sintered with direct current. Whereas, this difference is not obvious during the later sintering stage. When the sintering temperature is the same, the relative transverse rupture strength of the specimens sintered at various pulse frequencies is σ50 Hz>σ100 Hz>σ0 Hz. No obvious difference can be found from the microstructures of specimen sintered at various pulse frequencies under the sintering temperature of 1 100 ℃.
Key words: iron-based powders; pulsed electric current sintering; pulse frequency; microstructure; mechanical property
