Study on brazing process of Ti-22Al-25Nb alloy sheet

The brazing process of Ti-22Al-25Nb alloy sheet was studied. The influences on the microstructure and the tensile strength of the matrix from the brazing process were studied in this paper. The strength of the brazing joints was tested. A few of short rod O phases were dissolved and lots of O phases were grown up in the matrix during the brazing process as the brazing temperature being 960 ℃. The grain size of the matrix was increased without phase transition. With heat preservation time by 15, 30 and 60 min extended gradually, the room temperature strength of the matrix was decreased from 1 257 to 1 100 MPa and the average room temperature elongation was increased from 2.9% up to 3.4%, 5.8% and 5.0%. The optimized brazing technology parameters of Ti2AlNb alloy plate is 960 ℃/30 min/furnace cooling with the higher shear strength of the brazed joints as 152 MPa.