中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 20 No. 1 January 2010 |
(State Key Laboratory of Advanced Welding Production Technology,
Harbin Institute of Technology, Harbin 150001, China)
Abstract:In laser welding-brazing of Al alloy (5A06) and Ti alloy (Ti-6Al-4V) with rectangular CO2 laser spot and with Al-12Si filler wire, element Si enriches at the interface between Ti substrate and the filler metal. It is found that the Si diffusion behavior has a significant effect on the formation of interfacial intermetallic compounds. To analyze the Si diffusion behavior, a model for the prediction of the chemical potential for ternary alloy was established. According to the calculated results of the influence of the element content and temperature in Ti-Al-Si system on Si chemical potential, the diffusion behavior of Si element was analyzed for Ti dissolution and melting mode, which presents a good agreement with the experimental data. Further, formation mechanism of the interfacial intermetllic compound was clarified.
Key words: laser welding-brazing; diffusion behavior; chemical potential; interfacial reaction