Brazing process of TC4 titanium/ 304 stainless steel dissimilar materials honeycomb sandwich structure

TC4 titanium face sheet/304 stainless steel honeycomb core dissimilar materials honeycomb sandwich structures were brazed by Ti-37.5Zr-15Cu-10Ni and Ag-Cu28 brazing filler metals respectively. Microstructure of brazing interfaces and mechanical properties of honeycomb sandwich structures brazed by both brazing filler metals were comparatively analyzed in details. Results show that the wettability between 304 stainless steel honeycomb core and Ti-based brazing filler metal is poor and the hardness of brazed interface is relatively high, which lead to the low strength of Ti-37.5Zr-15Cu-10Ni brazed interface. Significant reaction has taken place between 304 stainless steel honeycomb core and Ag-based brazing filler metal. Honeycomb sandwich structure with the tensile strength of 10.35 MPa is attained at the brazing temperature of 830°C with the bolding time of 10 min. Compared with Ti-based brazing filler metal, Ag-based brazing filler metal is suitable for brazing TC4 titanium /304 stainless steel dissimilar materials honeycomb sandwich structures.