摘要
铝与钛的双金属结构具有广阔的应用前景,由于两种材料易形成氧化膜,物性差异很大且极易形成Ti-Al金属间化合物,连接难度非常大。基于电子束热源的熔-钎焊技术通过熔化低熔点的铝合金来润湿、钎接高熔点的钛合金,有效地控制界面反应,抑制金属间化合物地生成与长大,对焊缝的成形、微观组织结构以及接头性能进行分析,结果表明:利用电子束熔钎焊技术实现Al/Ti异种金属焊接接头的平滑过渡,焊缝正反面成形良好;Al和Ti这两种元素在焊接过程中都向对方基体中进行扩散,形成1.0～1.6 mm宽度的反应区,在TC4侧形成厚度为20～40μm的过渡层,5A06侧形成大量弥散分布的块状Ti-Al金属间化合物,实现5A06铝合金/TC4钛合金异种金属的冶金结合;焊接接头的抗拉强度达到180 MPa;焊缝无裂纹、气孔缺陷。
Al/Ti dissimilar aUoy.s joining components have potential to be widely used. But the oxidation film on the material surface, the property differences between A1/Ti alloys and the brittle intermetaUic compound form in the welding process are the key factors to increase the difficulties of joining these two alloys. The electron beam welding-brazing is used to joining 5A06 AI alloy to TC4 Ti alloy for controlling the liquid-to-solid interalloying reaction and the forming of brittle intermetallic compound to as small extent as possible. The welded seam appearance and the microstructure as well as the mechanical properties of the joints are analyzed. The results show that the welded seam is good shape as well as the back of the joint. A 1.0-1.6 mm thickness reaction zone is generated on the welding-brazing interface where AI and Ti element fully diffuse. The metallurgically bonded joint is gained during the electron beam welding-brazing and a transition layer formed in the TC4 side, while many small Ti-AI intermetallic compounds dispersed in the 5A06 side. The no-defect joints are gained and the maximum tensile strength of Al/Ti dissimilar alloy joints is up to 180 MPa.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2012年第20期88-92,共5页
Journal of Mechanical Engineering
关键词
铝合金
钛合金
电子束
熔-钎焊
Al alloy Ti alloy Electron beam Welding-brazing
