多孔结构Ni中间层对CuW/Al界面组织及性能的影响

Effect of Porous Structure Ni Interlayer on Microstructures and Properties of CuW/Al Interface

将CuW假合金表面部分Cu腐蚀掉,预留100~200μm厚度的W骨架,随后通过化学镀在W骨架上形成多孔结构Ni扩散层,最后在700℃下用固-液连接的方法制备出CuW/Al整体材料。比较了不同保温时间下界面扩散区域微观组织结构,分析了界面扩散溶解层金属间化合物析出序列。结果表明,CuW/Al界面间多孔结构Ni中间层可有效抑制柱状Al_2Cu相的生成和柯肯达儿孔洞裂纹的产生,界面处生成物主要以Al_2Cu和Al_5W化合物为主。添加多孔结构Ni中间层可提高CuW/Al界面结合性能和电导率。

A layer of W skeleton with 100~200 μm thickness was obtained by corroding the Cu of CuW surface. Then, a porous structure diffusion barrier layer was formed by electroless Ni plating on W skeleton. Finally, the CuW/Al bimetals was prepared by solid-liquid connection at 700 °C. The microstructure of interfacial diffusion layer at different holding time was investigated, and the precipitation sequence of the intermetallic compounds was analyzed. The results show that the porous structure Ni interlayer between CuW/Al interface can effectively reduce the amount of Al_2Cu compounds, and prevent the formation of Kirkendall voids. The CuW/Al interface mainly consists of Al_2Cu and Al_5W phases. By adding porous structure Ni interlayer, the interface bonding property and electrical conductivity of CuW/Al are improved.