【摘要】 为了降低汽车铝质热交换器钎焊温度，防止高温软化，研究了一种钎焊温度比Ａｌ－Ｓｉ钎料低的Ｚｎ－Ａｌ－Ｃｕ钎料．着重讨论了微量Ｃｕ含量对Ｚｎ－Ａｌ钎料熔点、强度、钎焊性能等的影响．研究结果表明，在Ｚｎ－Ａｌ系钎料中加入微量的Ｃｕ，对钎料熔点无影响，其熔点均在三元合金共晶温度３７３．５℃左右；微量Ｃｕ在Ｚｎ－Ａｌ系合金中形成以Ｚｎ为基的含有铝和铜的η相（富锌相）固溶体及含锌和铜的β相（富铝相）固溶体，提高了Ｚｎ－Ａｌ系钎料的强度、硬度，但使其延伸率降低．该合金完全能替代Ａｌ－Ｓｉ系钎料用于汽车热交换器的钎焊，焊接温度可降低２００℃左右，可以防止因炉温偏高造成铝质热交换器钎焊时的高温软化现象．更多还原

【Abstract】 おn order to lower the soldering temperature of aluminum heat exchanger and prevent softening at high temperature, a kind of ZnAlCu solder with lower soldering temperature comparable with AlSi braze is studied. The effect of the content of copper on melting point,strength,solderability is emphatically discussed. The investigation reveals that the addition of tittle Cu doesn′t affect the solder′s melting point, which is about the ternary eutectic point 3735 ℃. But the addition can help to bring the Zn base η phase(Zn rich solid solution) and the Zn base β phase(Al rich solid solution) in the ZnAl system so as to improve the strength and hardness of the ZnAl solder and lower its ductility. The solder can substitute the AlSi braze for the jointing of aluminum heat exchangers, lowering the working temperature in the range of about 200 ℃. Hence, the softening of aluminum parts due to high working temperature can be avoided.更多还原