摘要
采用锌夹层在356℃温度下对镁铝异种金属进行扩散焊连接,并对接头的微观组织和力学性能进行分析。结果表明,利用镁与锌原子互扩散形成低熔点共晶液相区,能够实现镁铝材料的可靠连接。镁铝焊接接头界面区由铝锌反应层、未充分扩散锌层、锌镁反应扩散层组成。铝基体侧铝锌反应层是固溶体层,镁基体一侧锌镁反应扩散层主要是过饱和的固溶体基体及弥散析出的中间相,该区的中间相成分为Mg2Zn11及MgZn2。锌夹层的加入可有效阻止镁铝之间的互扩散。锌夹层镁铝扩散焊接头抗剪强度远超过镁铝直接真空扩散焊接头的抗剪强度。断口观察及相分析表明,接头失效发生在锌镁反应扩散层。
The characteristics of microstructure and mechanical properties of the Mg/Al alloy joint by diffusion bonding with a Zn interlayer were studied by means of metalloscopy, X-ray diffraction, electron probe microanalysis and mechanical property test. Investigations showed that the Mg/Al alloy joint by diffusion bonding with Zn interlayer consists of a multilayer sandwich structure, including the transition zone of Zn-Al, the residual Zn interlayer, as well as the transition zone of Zn-Mg. The transition zone of Zn-Al is composed mainly of a solid solution structure, while the Zn-Mg transition zone has a relative larger dimension after a rapid eutectic reaction. The addition of zinc interlayer inhibits the inter-diffusion of Mg and Al alloy efficiently. The Zn-Mg transition zone constitutes the main part of the joint and consists of Mg and the new phases formed are Mg2Zn11 and MgZn2 intermetallic compound. According to the phase constitution analyses executed on each side of the fracture face, it was deduced that the fracture of Mg/Al alloy joint located around the interface of Zn-Mg transition zone. The average shear strength of Mg/Al alloy joints diffusion bonded with Zn interlayer reaches 70 MPa and exceeds that of the joints bonded without Zn interlayer enormously.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2007年第10期9-12,共4页
Transactions of The China Welding Institution
基金
国家"十一五"科技支撑计划资助项目(2006BE04B05)
关键词
镁合金
铝合金
锌夹层
扩散焊
接头强度
magnesium alloy
aluminum alloy
zinc interlayer
diffusion bonding
joint strength
