Al2O3陶瓷Ti+Nb/Mo金属化对其与Kovar合金钎焊连接的组织和力学性能的影响

Investigation of brazing joints of Al2O3 ceramics to Kovar alloys by Ti+Nb/Mo metallization

关键词:  氧化铝陶瓷  金属化  钎焊  磁控溅射

Key words:  Al₂O₃ ceramics  metallization  braze joint  magnetron sputtering

摘要:

采用磁控溅射在Al₂O₃陶瓷表面沉积了Ti+Nb/Mo金属层，实现了氧化铝陶瓷的金属化，并通过电镀镍提高了金属化效果.采用AgCu28钎料，实现了金属化Al₂O₃陶瓷与Kovar合金的可靠连接.通过扫描电子显微镜和能谱观察了钎缝的微观组织.结果表明，钎料与母材发生了明显的界面反应.Cu元素扩散进入Kovar合金，同时Ni元素扩散进入钎料的富铜区，从而促进AgCu/Kovar连接界面的形成；金属化层在Al₂O₃/AgCu钎料界面处，起到了关键作用，其中铌可以抑制脆性化合物形成，缓解残余应力.金属化层镀镍后，钎缝中AgCu共晶区明显，且钎缝较宽，对提高镀镍试样的钎焊接头强度有一定作用.

Abstract:

Ti+Nb/Mo thin films were deposited onto Al₂O₃ ceramic by magnetron sputtering with a subsequent nickel-plating to ensure the robust brazing of Al₂O₃ ceramic to Kovar alloy using the filler of AgCu28. Microstructures of the metallization layer and the brazing joints of Al₂O₃/Kovar were investigated systematically by scanning electron microscopy (SEM) and energy dispersive X-ray (EDS). The results show that the interfacial reaction layers are created between filler alloys and base materials. Interdiffusion of Ni and Cu at the interface of AgCu/Kovar resulted in the formation of the reaction layer. The metallization layer plays an important role in hindering the formation of intermetallic compounds and relieving residual thermal stress at Al₂O₃/AgCu interface. In addition, the presence of eutectic region arising from nickel-plating can improve the thickness of the brazing seam and therefore a good bonding betweenAl₂O₃ ceramic and Kovar was achieved.