Strength and structure of furnace-brazed joints between titanium and steel using silver-based braze alloy

摘要

The lap joint of a commercially pure titanium plate to a low carbon steel plate was produced by vacuum brazed furnace using Ag-Cu34-Ti2 filler alloy at various temperatures and lap widths to investigate the effects of the brazing parameters on the joint strength and structure. It is found that the shear strength of brazed joints depended strongly on the lap width. Within investigating parameters, it became obvious that with decreases the lap width the shear strength of the joints increases. The maximum shear strength of the joints was 54 MPa for the specimens brazed at 850℃ for 15 min. According to experimental observations, intermetallic compound layers of CuTi and Cu2Ti were formed at the interface area. Increasing the brazing temperature led to an increase and growth of these layers. The fracture path after shear test occurred mainly at CuTi layer since this layer was hard and brittle.