(華南理工大學(xué) 機械工程學(xué)院, 廣州 510640)
摘 要: 采用脈沖頻率為0、50和100 Hz的電流對高能球磨鐵基粉末進行脈沖電流燒結(jié), 并研究脈沖頻率對粉末的致密化行為、燒結(jié)材料的顯微組織和力學(xué)性能的影響。 結(jié)果表明, 通電燒結(jié)初期脈沖電流燒結(jié)樣品的密度和硬度均高于直流電流燒結(jié)的試樣, 但通電燒結(jié)后期使用脈沖電流與直流電流所燒結(jié)樣品的密度和硬度差別不大； 相同燒結(jié)溫度下不同脈沖頻率燒結(jié)試樣的橫向斷裂強度的相對大小為σ50 Hz>σ100 Hz>σ0 Hz； 當(dāng)燒結(jié)溫度為1 100 ℃時, 不同脈沖頻率下所獲得的燒結(jié)材料的顯微組織沒有顯著差別。
關(guān)鍵字: 鐵基粉末； 脈沖電流燒結(jié)； 脈沖頻率； 顯微組織；力學(xué)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
