The brazing of Al2O3 and various metals using 72Ag-28Cu active braze alloys contain small amounts of titanium has been extensively studied. Ti can form a Ti3Cu3O layer on the substrate’s surface, so the molten braze can effectively wet the Al2O3 substrate. Higher Ti content in the braze alloy has better wetting ability, but it will form more intermetallic compounds, hence lowering the bonding strength. Brazing at higher temperature and longer time will result in more substrate’s ellements diffusing into the brazed joint and thicken the thickness of intermetallic layers on the substrate. The brazed joint is primarily consists of Ag-rich, Cu-rich and Cu-Ti intermetallic phases. For the brazing of Al2O3 and Zr, when the brazing temperature is above 830℃, all phases in the brazed joint is alloyed with a lot of Zr due to the diffusion of Zr substrate into the brazed joint. Because the difference of CTE between substrates is too huge, Al2O3 will crack except for brazing Al2O3 with Nb and Zr. Another study is brazing stainless steel using Cu/Ni fillers in order to produce plate heat exchanger’s brazed joints with good corrosion resistance. Using powder fillers cause Cu-rich and Ni-rich phases separated, so the Cu-rich phase can’t alloyed with enough Ni content. If Ni content in the filler is further increased, filler’s melting point is increased and demonstrates poor wettability. If filler contains B, B-Cr-Fe internetallics is formed along substrate’s grain boundaries, hence lowering the bonding strength. Brazing using the Cu foil placed between Ni clad 304 stainless steel substrates can make brazed joints with good corrosion resistance without flaws mentioned above, demonstrating the best result.