摘要
W-Cu复合材料具有热膨胀系数低、导电性好、导热性好、高熔点、高硬度以及良好的抗电弧烧蚀性能,在机械加工、电气工程以及电子信息领域被广泛用作电极材料、电接触材料、电子封装材料及靶材等越来越受到国内外的关注。传统粉末冶金方法制备的W-Cu复合材料致密度低、组织结构粗大且均匀性差,严重影响材料性能。采用纳米复合新技术制备的W-Cu复合材料具有很大的技术优势:粉末纳米化使得粉末的烧结活化能大大降低,其烧结活化能在1 420℃时仅为42.1 kJ/mol和29.1 kJ/mol,远低于纯W相同温度范围内的587.9 kJ/mol,同时纳米复合使得W与Cu发生了固溶,从而使得复合粉末表现出良好的烧结活性。采用纳米复合制备的细晶W-Cu复合材料具有非常优异的综合性能,其原因在于经烧结后获得高的致密度和组织结构均匀细小。
W-Cu alloys have been used for electrode materials,electrical contact materials in machining,electrical engineering and electronic information fields due to the high melting point,low thermal expansion coefficient,welding resistance,anti-corrosion resistance and high thermal conductivity.W-Cu alloys prepared by traditional methods are difficult to meet current requirements because of low density,heterogeneous organizations,so their applications are restricted.In contrast,fine-grained W-Cu materials have many advantages.Powder nanocrystallization makes the sintering activation energy become much lower,where the sintering activation energy are only 42.1 kJ/mol and 29.1 kJ/mol for W-10Cu and W-20Cu nanocomposite powder at 1 420 ℃ respectively.At the same temperature,the densification activation energy is 587.9 kJ/mol for pure W.At the same time,nanocrystallization makes W and Cu take place solid solution,so composites show good sintering activity.Fine-grained W-Cu composites show very excellent integrated performance because they have high density,uniform and fine structure.
出处
《硬质合金》
CAS
北大核心
2011年第1期56-65,72,共11页
Cemented Carbides
基金
国家杰出青年基金(50925416)
国家自然基金(50874122)
国家自然科学基金委员会创新研究群体科学基金(50721003)
关键词
钨铜复合材料
细晶
烧结活化能
致密化
性能
W-Cu composite materials
fine grain
sintering activation energy
densification
performance
