镍/钼复合中间层钎焊连接C/C复合材料和304不锈钢

Brazing of C/C composites and 304 stainless steels via Ni/Mo composite interlayer

本文使用在BNi-2或AgCuTi箔片钎料中添加金属中间层(Ni、Mo或Ni/Mo)的方法有效提高了C/C复合材料和304不锈钢真空钎焊接头的强度,并先后对接头的微观结构、连接机理和力学性能进行分析。分析表明,BNi-2+Ni/Mo接头的微观结构包括Cr_(3)C_(2)、Ni(s,s)、Cr_xNi_(y)+MoNi_(4)、MoNi_(4)+Cr_(x)M_(y)和Ni(s,s)+Cr-Fe;AgCuTi+Ni/Mo接头的界面则由TiC、Ag(s,s)+Cu(s,s)、Ni、Ag(s,s)+Cu(s,s)+MoTi、Mo和MoTi+Cu(s,s)+Ag(s,s)构成。有限元模拟结果表明,AgCuTi钎料加持下的镍/钼复合中间层能够有效缓解C/C母材与焊缝界面间的残余应力。室温下BNi-2+Ni/Mo、AgCuTi+Ni、AgCuTi+Mo和AgCuTi+Ni/Mo钎焊接头的平均剪切强度分别为2.57 MPa、10.91 MPa、23.81 MPa和26.77 MPa,有效验证了有限元结果的可靠性。

In order to improve the strength of C/C composites and 304 SS brazed joint,two substrates were brazed by adding metal interlayers(Ni,Mo,Ni/Mo)to BNi-2 or AgCuTi filler metals.The objective of this study was to investigate the microstructure,joint mechanism,and mechanical properties of the brazed joints.The findings revealed that the microstructure of the BNi-2+Ni/Mo joint consisted of Cr3C2,Ni(s,s),CrxNiy+MoNi4,Mo,MoNi4+CrxMy,and Ni(s,s)+Cr-Fe.The interfacial microstructure of the AgCuTi+Ni/Mo joint in the control experiment consisted of TiC,Ag(s,s)+Cu(s,s),Ni,Ag(s,s)+Cu(s,s)+MoTi,Mo,and MoTi+Cu(s,s)+Ag(s,s).Finite element simulations demonstrated that the Ni/Mo composite interlayer effectively alleviated residual stresses in the C/C substrates.The average shear strength of the BNi-2+Ni/Mo brazed joints at room temperature was found to be 2.57 MPa,while the average shear strength of the AgCuTi+Ni,Mo,and Ni/Mo joints were 10.91 MPa,23.81 MPa,and 26.77 MPa,respectively.