摘要本文针对高强铝合金多层腔型结构整体真空钎焊易出现的问题，以Mg,Sr,La作为添加元素，通过调整不同因子的含量，设计熔炼了9组成分试样。以3A21铝合金为母材，通过进行钎料铺展性实验来测得各试样的钎着率。试验结果表明： Mg元素的添加，可以降低Al-Si基钎料的熔点。加入稀土元素La，可提高钎料润湿性能。  67689    

通过对钎焊后接头微观组织分析，发现基础合金部分Al占85%，Si占13%，Mg占1.8%，并加入微量稀土元素的钎料试样焊后界面尺寸较厚，界面反应快，化合物在晶界处偏聚度小，因而焊缝强度高，稀土元素的加入会起到变质作用产生离异共晶，可以细化晶粒，改善杂质在晶界处的偏聚，得到性能优良的钎焊接头。 

毕业论文关键词  高强铝合金  真空钎焊  润湿性 

毕业设计说明书（论文）外文摘要

Title  Study on high strength aluminum alloy vacuum brazing process 

Abstract

This paper in the light of the whole vacuum multi-layer structure of high strength aluminum alloy brazing problems, with Mg, Sr, La as additive elements, through adjusting the contents of different factors, design of smelting 9 component sample. 3A21 aluminum alloy was used as the base material, by spreading solder to experiment measured the samples brazed rate. The test results show that: the addition of Mg element, can reduce the Al-Si based solder melting point. Addition of rare earth elements La, can improve the wettability of brazing filler metal.

The microstructure of brazing alloy, that the basis of the Al accounted for 85%, Si accounted for 13%, Mg accounted for 1.8%, and add solder specimen welding trace rare earth elements interface when the size is thicker, the interfacial reaction is fast, compounds in the grain boundary segregation degree is small, so the weld of high strength, rare earth elements added the metamorphism have porced eutectic, can refine the grain, improve grain boundary segregation of impurities in the brazed joint, get excellent performance.

Keywords: High strength aluminum alloy  vacuum brazing  wettability

目  次

1  引言 1

1.1  课题的意义 1

1.2  铝合金钎料的研究现状 1

1.3  真空钎焊技术 2

1.4  铝合金毫米波构件的钎焊 4

1.5  论文研究的内容 4

2  试验准备及方法 5

2.1  试样材料 5

2.2 试验研究方案 6

2.3  试验设备及方法 7

3  高强铝合金多层腔型结构专用钎料性能测定 10

3.1 钎料组分设计 10

3.2钎料试样金相组织研究 14

3.3 钎料试样熔化特性分析 15

3.4 钎料润湿性能 20

4 铝合金多层腔型结构真空钎焊工艺试验 24

4.1 钎料试焊 24

4.2接头微观组织分析 26

结  论 30

致  谢 31

参考文献 32

1  引言