材料期刊网

Microstructural evolution of infrared vacuum brazing CP-Ti using two Ti-based braze alloys, Ti-15Cu-15Ni and Ti-15Cu-25Ni, have been investigated. The infrared brazed joint consists of eutectic Ti2Cu/Ti2Ni intermetallic compounds and Ti-rich matrix. The eutectic Ti2Cu/Ti2Ni intermetallic compounds are disappeared from the joint after 1h annealed at 900oC. In contrast, the depletion rate of both Cu and Ni from the braze alloy into CP-Ti substrate at 750oC annealing is greatly decreased as compared with that annealed at 900oC. Blocky Ti2Cu/Ti2Ni phases are observed even if the specimen is annealed at 750oC for 15h. Because the Ni content of the Ti-15Cu-25Ni braze alloy is much higher than that of the Ti-15Cu-15Ni alloy, the amount of eutectic Ti2Cu/Ti2Ni phases in Ti-15Cu-25Ni brazed joint is more than that in Ti-15Ci-15Ni brazed joint. However, similar microstructural evolution can be obtained from the infrared brazed joint annealed at various temperatures and/or time periods for both filler metals.