Microstructure and crack sensitivity of electron beam welded titanium aluminide joints
来源期刊：中国有色金属学报(英文版)2005年第z2期
论文作者：吴会强 冯吉才 何鹏 何景山
文章页码：1 - 4
Key words：crack； titanium aluminide； electron beam welding； microstructure
Abstract: Microstructural characterization and crack formed mechanism during electron beam welding of titanium aluminide Ti-45Al-1.7Cr-1.7Nb were investigated. The results show that the welded microstructure exhibits columnar and dendritic structure. Microstructural constituents in the fusion zone are a massive gamma structure and some lamellar structure consists of alternating platelets of α2 and γ. The major contributing factor of the susceptibility to solidstate cracking is thermally induced stress. The import role of the suppression of the α phase decomposition, the difference of α2/γ phases thermal expansion coefficient and the lamellar spacing changes of lamellar structure with cooling rate all play effect on the crack forming mechanism.
