Microstructure and mechanical properties of TiC/Ti matrix composites and Ti–48Al–2Cr–2Nb alloy joints brazed with Ti–28Ni eutectic filler alloy

Abstract Ti–48Al–2Cr–2Nb and TiC/Ti matrix composites were successfully joined using Ti–28Ni eutectic filler metal at different brazing temperatures. Microstructure and mechanical properties of the joints were systematically studied. The results showed that the joints all showed integral interfaces and the microstructures of the joints for 980 °C/15 min were detected as Ti-48Al-2Cr-2Nb/α2-Ti3Al + τ3-Al3NiTi2/α2-Ti3Al/Ti(s,s) + δ-Ti2Ni + TiC/Ti matrix composites. As brazing temperature increased, continuous Ti2Ni layer diminish and Ti2Ni phase became more discrete. However, α2-Ti3Al rich layer has thickened which deteriorates the properties of the joints. The highest shear strength achieved 469.5 MPa as the joint brazed at 1010 °C for 15 min. The evolution of microstructures brazed with different temperatures was studied and its relationship with the shear strength was also revealed in details.