While the second type is Al-based brazing filler, such as
63Al-16.5Ag-20.5Ge and 40.0Al-40.7Ag-19.3Cu, with
the melting points of 414.5 °C and 500 °C, respectively
[39−40]. Previous attempts to develop low-melting-point
filler metals for brazing Al-matrix composites have not
met with commercial requirement due to the poor
mechanical properties of the alloys, corrosion of the
joints, toxicity, high cost of constituent metals and
volatility of the constituents.