Liquation Cracking Tendency of Novel Al-Mg-Zn Alloys with a Zn/Mg Ratio below 1.0 during Fusion Welding
Liquation Cracking Tendency of Novel Al-Mg-Zn Alloys with a Zn/Mg Ratio below 1.0 during Fusion Welding
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DOI：
10.3390/met10020222
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发表时间：
2020-02
期刊：
影响因子：
2.9
通讯作者：
Di Zhang;Xin Zhao;Yanlin Pan;Hongxiang Li;Li Zhou;Ji-shan Zhang;L. Zhuang
中科院分区：
文献类型：
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作者：
Di Zhang;Xin Zhao;Yanlin Pan;Hongxiang Li;Li Zhou;Ji-shan Zhang;L. Zhuang
高强度7×××系列铝合金应用的主要障碍是这些合金在熔焊过程中易产生热裂纹。采用环形补焊试验研究了Zn/Mg比小于1.0的新型T-Mg 32（AlZn）49相强化Al-Mg-Zn合金的液化开裂敏感性，并与Zn/Mg比大于1.0的η-MgZn 2相强化7×××系列合金的液化开裂倾向进行了比较。结果表明，这些新型Al-Mg-Zn合金的液化开裂敏感性与传统的5×××系列合金相当，明显优于传统的7×××系列合金。结果表明，随着Zn/Mg比的增加，凝固终了阶段熔合区和部分熔化区的固体分数差异增大，导致熔合区和部分熔化区的裂纹愈合差异增大，从而导致不同合金的液化开裂倾向不同。
The main obstacle for the application of high strength 7××× series aluminum alloys is that these alloys are susceptible to hot cracking during fusion welding. This study presents the liquation cracking susceptibility of the novel T-Mg32(AlZn)49 phase strengthened Al-Mg-Zn alloy with a Zn/Mg ratio below 1.0 by a circular-patch welding test, and compared the liquation cracking tendency with η-MgZn2 phase strengthened 7××× series alloys whose Zn/Mg ratios are above 1.0. It was found that all these novel Al-Mg-Zn alloys still have as low a liquation cracking susceptibility as traditional 5××× series alloys, surpassing that of traditional 7××× series alloys substantially. It was noticed that the increase of the Zn/Mg ratio will result in a larger difference between the fraction solids of the fusion zone and the partially melted zone during the terminal solidification stage, which can lead to a wider crack healing disparity between these two areas and thus result in different liquation cracking susceptibilities in different alloys.