摘要
分别采用Zn-15Al,Zn-22Al,Zn-28Al,Zn-37Al和Zn-45Al钎料钎焊获得Cu/Al接头.利用SEM,EDS和XRD研究了Zn-Al钎料成分对Cu/Al接头中Cu母材/钎缝界面结构的影响,并系统阐述了Zn-Al钎料成分-接头界面结构-接头抗剪切强度之间的关系.研究发现,Cu/Zn-15Al/Al接头中Cu母材/钎缝界面结构为Cu/Al4.2Cu3.2Zn0.7,且Al4.2Cu3.2Zn0.7界面层较薄,其厚度为2~3μm,接头具有较高的抗剪切强度,达66.3 MPa.随着钎料中Al含量的提高,在Cu/Zn-22Al/Al接头界面处Al4.2Cu3.2Zn0.7界面层的厚度逐渐增大,甚至在Cu/Zn-28Al/Al接头的Al4.2Cu3.2Zn0.7界面层附近出现少量的Cu Al2,接头的抗剪切强度逐渐降低.当采用Al含量较高的Zn-37Al钎料钎焊Cu/Al接头时,Cu母材/钎缝界面结构转变为Cu/Al4.2Cu3.2Zn0.7/Cu Al2;脆性Cu Al2层的出现,使接头抗剪切强度大幅下降,为34.5 MPa.当采用Al含量最高的Zn-45Al钎料钎焊Cu/Al接头时,Cu母材/钎缝界面结构转变为Cu/Cu Al2,接头抗剪切强度最低,为31.6 MPa.
The Cu/Al dissimilar metal joint is a compound structure that can efficiently decrease manufacturing costs, reduce product weight, and integrate the advantages of both metals. For the excellent comprehensive properties, the Cu/Al dissimilar metal joint has broad application prospects in air conditioners, refrigerators, cables,electronic components, solar collectors, et al. Brazing is considered as a promising method to join the Cu/Al dissimilar metal for lower residual stress, lower costs, higher precision and better adaption to the structure of joint.Meanwhile, the Zn-Al filler metal is considered as the relatively ideal filler metal due to better property of the Cu/Zn-Al/Al joint. However, the influence of the composition of the Zn-Al filler metal on the interfacial structure near Cu substrate and property of the Cu/Al joint has not been investigated. In this work, the Cu/Al joints were brazed by Zn-15 Al, Zn-22 Al, Zn-28 Al, Zn-37 Al and Zn-45 Al filler metals, respectively. The influences of the composition of Zn-Al filler metals on the interfacial structure near Cu substrate of the Cu/Al joints were investigated, andthe relationships of the composition of the Zn-Al filler metals, the interfacial structure and the shear strength of the Cu/Al joints were described systematically. It was found that the interfacial structure of the Cu/Zn-15Al/Al brazed joint was Cu/Al4.2Cu3.2Zn0.7. For thinner Al4.2Cu3.2Zn0.7layer（2~3 μm）, the shear strength of the joint was higher（66.3 MPa）.With the increase of Al content of the filler metal, the thickness of Al4.2Cu3.2Zn0.7layer at the interface was increased for Cu/Zn- 22Al/Al joint, even some Cu Al2 phase can be found nearby the Al4.2Cu3.2Zn0.7layer of Cu/Zn- 28Al/Al joint, and the shear strength of the Cu/Al joints were decreased correspondingly. When the Cu/Al joint was brazed by the Zn-37 Al filler metal, the interfacial structure near Cu substrate was transformed into Cu/Al4.2Cu3.2Zn0.7/Cu Al2.For higher brittleness of Cu Al2 layer, the shear strength of the joint was decreased obviously（34.5 MPa）. Finally,the interfacial structure of the Cu/Zn-45Al/Al joint was transformed into Cu/Cu Al2, the interfacial structure lead to the lower shear strength of the joint, which is only 31.6 MPa.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第3期364-370,共7页
Acta Metallurgica Sinica
基金
广东省科技计划资助项目2010A080402014~~
