中文摘要：

使用正交试验法设计9组添加不同含量Cu、Zn、La元素的Al-4Si基钎料,分析了钎料对LF6铝合金润湿性的影响,并采用润湿性最好的钎料对LF6铝合金进行炉中钎焊,测试了接头剪切强度。结果表明,钎料组织由琢-Al基体相、初晶Si相、Al2Cu（兹）相及La Si相组成,并且随着La含量的增加,钎料中初晶Si相成形更加良好;随着Zn含量的增加,钎料中的Al2Cu（兹）相的形状由网状转变为多边形块状。La元素对钎料的铺展性影响较大,Cu元素其次,Zn元素相对比较弱。由正交试验得出6号钎料Al-4Si-15Cu-35Zn-0.2La的铺展面积最大,为226.87 mm2,钎料液相线为499℃,在530℃保温15 min条件下LF6铝合金钎焊接头平均剪切强度为101.03 MPa。

英文摘要：

The 9 groups of A1-4Si filler metal with different content ofCu, Zn and La were designed by using orthogonaltest method, and the effect of filler metal on the wetability of LF6 was analyzed, and LF6 alloy was brazed with the filler metalwhich has best wetability, and the shear strength of the brazing joint was tested. The results show that the major phases of fillermetal are ct-A1, primary Si, AI~Cu （0） and LaSi. With the increase of the content of La, the primary Si phase forming of thesolder is more favorable, and with the increase of the content of Zn, the shape of A12Cu （0） changes from net to polygon. Laand Cu have stronger effects on spreadability than Zn. The orthogonal results show that No.6 group filler metalA1-Si-15Cu-35Zn-0.2La has the maximum spreading area which is 226.87 mm2, the liquid temperature of AI-Si-15Cu-35Zn-0.2La is 499℃ and average shear strength of brazing joints under 530℃ holding for 15 min is 101.03 MPa.