TiAl/IN718合金过渡液相连接

采用过渡液相TLP(Transient Liquid Phase)连接技术,以金属Ti,Cu,Ni箔构成复合焊料连接TiAl和IN718合金.研究了保温时间对接头界面结构的影响.实验结果表明:采用Ti-Cu,Ti-Ni复合焊料可以制备无缺陷的接头,但2种焊料形成液相的过程和机理不同.由于在等温凝固过程中,从IN718合金中扩散过来的合金元素可在焊缝区聚集,从而在接头中形成亚层结构.通过对接头焊缝区的组织分析和硬度测试表明,在实验条件下Ti-Ni焊料的等温凝固过程持续时间比Ti-Cu的短.

Transient liquid phase bonding of TiAl and Inconel 718

Ti foil combined with Cu or Ni foils was used as insert metals to join TiAl intermetallic and Inconel 718 employing transient liquid phase (TLP) bonding technique. The effect of dwell time at bonding temperature on the interfacial structures of the joints was investigated. Results showed that defect-free joints was fabricated, but the liquid formation processes and mechanism of Ti-Cu and Ti-Ni insert metals were quite different. Some sublayers were found in the joined zone because the alloyed elements which diffused from Inconel 718 alloy segregated at the interface between Inconel 718 alloy and joined zone. Morphologies and hardness profiles of the joined zones showed that the joint produced using Ti-Ni insert metals could isothermally solidify much faster than that produced using Ti-Cu insert metals under the experimental conditions.