2001 Volume 19 Issue 2 Pages 278-286
We tried to braze commercially pure titanium (CPTi) at the temperature below its transformation temperature of 882°C using Ag-based filler metal in argon atmosphere. The effect of brazing temperature, isothermally holding time and brazing pressure on the strength and the microstructure of brazement was examined. In addition, ultrasonic vibration was applied during brazing in order to improve the performance of the brazement. The following results were obtained in this study.
By using BAg-7 filler metal, CPTi could be successfully brazed below its transformation temperature, and the brazement had the strength equivalent to the base metal.
The strength of the brazement increased with brazing temperature and isothermally holding time at that temperature. This was because brittle intermetallic compounds disappeared from the brazed region. The disappearance of the intermetallic compounds accelerated with the increase of brazing pressure because extra molten filler metal could be more effectively expelled from the brazed region.
Application of ultrasonic vibration during brazing was capable of increasing the strength of the brazement at lower temperature and lower brazing pressure for shorter holding time than when no ultrasonic vibration was applied.
