Vacuum brazing of high volume fraction particles reinforced aluminum matrix composites.

This experiment chooses A356 aluminum matrix composites containing 55% particle reinforcing phase as the parent metal and ---- alloy metal as the filler metal. The brazing process is carried out in vacuum brazing furnace at the temperature of 550°C and 560°C for 3 min, respectively. The interfacial microstructures and fracture surfaces are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy spectrum analysis (EDS). The result shows that adequacy of element diffusion are superior when brazing at 560°C, because of higher activity and liquidity. Dislocations and twins are observed at the interface between filler and composite due to the different expansion coefficient of the aluminum alloy matrix and particles. The fracture analysis shows that the brittle fracture mainly located at interface of filler and composites. [ABSTRACT FROM AUTHOR]