AgCu钎料钎焊TC4钛合金与QCr0.8铬青铜接头界面结构及性能

采用AgCu28钎料实现了TC4钛合金与QCr0.8铬青铜的真空钎焊，利用SEM, EDS以及XRD等分析方法确定TC4/AgCu/QCr0.8接头的典型界面结构为TC4钛合金/CuTi +Cu3Ti2 +CuTi2/Ag(s,s) +Cu4Ti/Ag(s,s)+Cu(s,s)/QCr0.8铬青铜. 研究了工艺参数对接头组织和性能的影响. 结果表明，随着钎焊温度和保温时间的增加，钎缝中银铜共晶组织减少，钛铜化合物增多. 接头抗剪强度随钎焊温度的升高先增加后降低，在钎焊工艺参数为890 ℃/0 min时，获得最大抗剪强度449 MPa.保温时间的延长使得接头脆性钛铜化合物增多，接头性能下降，因此随保温时间延长接头抗剪强度显著降低.

Interfacial microstructure and properties of TC4/QCr0.8 joints brazed with AgCu filler

QCr0.8 alloy was brazed to TC4 by using AgCu filler metal in vacuum. The typical interfacial microstructure of TC4/AgCu/QCr0.8 brazed joint was TC4/CuTi+Cu3Ti2+CuTi2/Ag(s,s)+Cu4Ti/Ag(s,s) +Cu(s,s)/QCr0.8, which was determined by SEM, EDS, and XRD. The effects of brazing temperature and time on microstructure and mechanical property were studied. Results show that the amount of AgCu eutectic phase decreased while that of Ti-Cu compounds increased with brazing time and temperature increases. Shear strength of the joints exhibited rising firstly and then declining pattern as temperature rose, and the maximum shear strength of 449 MPa was obtained under the condition of 890 ℃/0 min. The growth of Ti-Cu compounds as brazing time extended deteriorated the property of the joint. As a result, the shear strength of the joints significantly declined with extended brazing time.