Microstructure and phase constitution near interface of Cu/Al vacuum brazing

Abstract

Dissimilar metals of copper (T2) and aluminium (1035) were brazed by vacuum brazing technology. Microstructure and phase constitution for the Cu/Al vacuum brazing were studied by means of metallography, electron probe microanalyser and X-ray diffraction. Experiment results indicated that an obvious transition layer of copper based solution was formed near the interface of copper and braze metal. The brazing seam zone mainly consists of various solid solutions between many elements and a few intermetallic compounds which are hard and brittle. This is favourable to the enhancing of service performance of the Cu/Al brazed joint. Process parameters of vacuum brazing are: brazing temperature T=425°C, vacuum level=10 −3 Pa, holding time t=15 min.