The Influence of Silicon Particle Morphology on the Melting Mechanism of Aluminium Brazing Sheet

The microstructure and silicon particle morphology of Al-Si cladding alloys are known to influence brazing properties and the quality of brazed joints. This paper reviews published literature on Al-Si system, melting mechanisms, grain size, solid state silicon particle growth and the influence on brazed joint formation. Common filler metals used for brazing sheet were thermally treated to modify Si morphology. The resultant microstructures were examined and Differential Scanning Calorimetry used to establish thermodynamic properties. The impact of silicon concentration and particle morphology on the melting kinetics is discussed.