球磨时间与含碳量对铜碳复合材料组织与性能的影响

Effects of ball-milling time and content of carbon on microstructure and properties of copper-carbon composite materials

将铜粉和碳粉分别按质量分数为Cu-2%C和Cu-8%C配比混合,经过高能球磨得到铜-碳复合粉末,然后冷压成形,压坯在H2气氛、820℃温度下烧结2 h,获得铜-石墨块体材料。采用X射线衍射、扫描电镜、透射电镜以及电导率测试仪等对高能球磨后的复合粉末和块体材料的物相组成、微观组织结构与导电性能进行分析,研究球磨时间与碳含量对铜-碳复合粉末与块体材料的组织结构及性能的影响。结果表明,铜碳混合粉末经高能球磨,得到亚稳态Cu(C)过饱和固溶体,经固相烧结后形成"蠕虫状"组织。随球磨时间延长,材料密度先增加后减小,球磨24 h时密度最大,Cu-2%C和Cu-8%C材料的密度分别为7.58 g/cm3和6.79 g/cm3;电导率随球磨时间延长而增加,球磨72 h时Cu-2%C和Cu-8%C的电导率分别为54.2%IACS和33.0%IACS。

Cu-2%C and Cu-8%C composite powders were prepared by high-energy ball milling copper and carbon powders. The composite powders were cold compressed and sintered at 820 ℃ for 2 h in HE atmosphere. The phase composition, microstructure and electrical conductivity of the composite powders after high-energy milling and compacts after sintering were detected by X-ray diffraction, scanning electron microscope, transmission electron microscopy and electrical conductivity test instrument. The effects of ball-milling time and content of carbon on microstructure and properties of the copper-carbon composite powders and compact materials were also studied. The results show that carbon-copper metastable supersaturated solid solution can be obtained by high-energy ball milling copper and carbon powder at room temperature. The microstructures of Cu-C composite materials show worm-like morphology after solid sintering. The maximum density values of Cu-C composite material with Cu-2%C of 7.58 g/cm3 and Cu-8%C of 6.79 g/cm3 are obtained when ball milling time is 24 h. The maximum electrical conductivity values of Cu-C composite materials with Cu-2% of 54.2/%IACS and Cu-8% of 33.0/%IACS are obtained when ball milling time is 72 h.