Brazing SiCf/SiC and TZM alloy with AuPdTiCrCu dual active element filler metal

Abstract

AbstractFor the joining of SiCf/SiC and TZM alloy, an AuPdTiCrCu filler metal with dual active element of Ti and Cr was synthesized. The brazing process was carried out under the condition of 1200°C for 10 min. It was shown that fine Cr‐based solid solutions were dispersed in the filler metal. When brazing, the element Cr and Ti moved toward the base metal and reacted with them to form into Mo‐Cr‐Si and Mo‐Cr‐Ti‐Si compounds. These two active elements could promote the metallurgical reaction of the joint. Meanwhile, it was found that some Pd‐Si compounds, fragments of (Au, Cu)ss and soft Au‐Ti phases formed in the middle regions of the joint. (Au, Cu)ss and Au‐Ti phases distributed around the Pd‐Si compounds. In addition, the joining mechanism was discussed and the mechanical properties of the joints were tested. The results showed that the average four point flexural strength of the joints reached 88.5 MPa at room temperature and 46.8 MPa at 500°C. The fracture characters of the joints were discussed in the last.