(中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 對(duì)Mg/Al異種金屬進(jìn)行真空擴(kuò)散焊接，采用SEM和XRD等手段分析接頭界面微觀結(jié)構(gòu)和相成分，研究Mg/Al界面組織結(jié)構(gòu)的演變規(guī)律，測試接頭的抗彎強(qiáng)度。結(jié)果表明：真空擴(kuò)散焊接能夠?qū)崿F(xiàn)Mg1/Al1060的連接；擴(kuò)散焊接過程中，界面發(fā)生擴(kuò)散反應(yīng)生成中間相Mg2Al3和Mg17Al12，且Mg2Al3相生長速率要快于Mg17Al12相；中間相由初始的島狀組織，經(jīng)縱向長大相互連接，最后形成均勻平直的擴(kuò)散反應(yīng)層；接頭最高抗彎強(qiáng)度為36.3MPa，斷裂發(fā)生在擴(kuò)散反應(yīng)層，屬于準(zhǔn)解理斷裂。
關(guān)鍵字: 真空擴(kuò)散焊接；Al1060；Mg1；顯微組織；抗彎強(qiáng)度
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The dissimilar metals of Mg and Al were welded by vacuum diffusion bonding. The microstructure and phase constitution at the interface of Mg/Al joints were characterized via SEM and XRD, and the evolution rule of interface microstructure was analyzed. The bending strength of the joints was tested. The results indicate that Mg1 and Al1060 can be joined by vacuum diffusion bonding. In the diffusion process, the intermediate phases of Mg2Al3 and Mg17Al12 form when the diffusion reaction occurs at the interface, and Mg2Al3 phase grows faster than Mg17Al12 phase. The island-like structures formed by intermediate phases gradually links to each other by longitudinal growth and finally forms a uniform and flat diffusion layer. The highest bending strength of the joint is 36.3 MPa and a fracture occurs in the diffusion layer which belongs to quasi-cleavage fracture.
Key words: vacuum diffusion bonding; Al1060; Mg1; microstructure; bending strength
