Possibility of Al-Si Brazing Alloys for Industrial Microjoining Applications

Aluminium alloys have been used widely since hundreds of years in automotive joining. Silicon is an excellent alloying element that increases the fluidity, depresses the melting temperature and prevents shrinkage defects during solidification, and is cost effective raw material. In recent few decades, research on cast Al-Si alloys has been expanding globally in military, automobile and aerospace industries. These alloys are good wear and corrosion resistant which depends on processing parameters and service conditions. However, the formation of big Si-needles in Al-Si alloys is a serious issue in joining industries. Silicon modification treatments are generally carried out to improve their durability and strength. This paper covers an elaborative study of various Al-Si alloys, the modification strategies to refine the Si-needles, effect of processing parameters and joining characteristics for automotive applications.