摘要
制备了含Ce的Al-Si-Cu系列钎料,用于6061铝合金和1Cr18Ni9Ti奥氏体不锈钢异质钎焊的研究。采用差示扫描量热法(DSC)和铺展润湿性试验分析稀土Ce对钎料熔化特性及在6061铝合金表面铺展润湿性的影响。利用万能拉伸试验机测试钎焊接头的力学性能,使用SEM,EDS等方法分析钎缝的微观组织,探究Ce对钎缝组织及力学性能的影响。研究表明:加入少量的Ce(≤3.0%,质量分数)不改变Al-Si-Cu钎料熔点,但使钎料熔化温度区间变窄,提高钎料流动性及在铝合金表面的铺展性。不同Ce含量对钎焊接头的力学性能影响不同。当钎料中Ce含量为1.0%(质量分数)时,钎缝微观组织细化,钎焊接头剪切强度最高,达到118 MPa;当钎料中Ce含量为3.0%(质量分数)时,钎缝组织中针状富Ce脆性化合物相明显增多,钎焊接头剪切强度降低为92 MPa。
A series of Al-Si-Cu filler metal with rare earth cerium(Ce) additions were developed to braze 6061 aluminum alloy to lCrl8Ni9Ti stainless steel.The influence of Ce on the filler melting characteristic was studied by means of DSC,and the wettability experiments were carried out on 6061 aluminum alloy surface.The shearing strength of the joint was measured by universal test machine,and the microstructure of the brazed seam was studied by SEM and EDS.The results revealed that the addition of the rare earth cerium into Al-Si-Cu filler metal cannot change its melting point when the Ce content was less than 3.0 wt.%,but shorten the melting temperature interval,improve the fluidity and spreadability on the surface of aluminum alloy.The shearing strength test result showed that the cerium(Ce) additions have great influence on mechanical properties of the joint.The shear strength of joint is 118 MPa for the Ce element content of 1.0 wt.%that refined the microstructure in brazed seam.However,when the Ce elements content reached 3.0 wt.%,the shear strength of brazed joint reduces to 92 MPa due to the significantly increasing of the needle-Ce-rich brittle phase in microstructure of the brazed seam.
出处
《焊接》
北大核心
2013年第12期47-50,71,共4页
Welding & Joining
