稀土元素Sc对Al-Si-Cu钎料性能的影响

发布时间：2018-01-25 00:01

本文关键词： 6063铝合金钎料稀土元素力学性能铺展性　出处：《合肥工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：6000系列热处理Al合金钎焊问题一直是国内外研究的重点,由于缺少综合性能良好的低熔点钎料,其钎焊后母材的软化问题一直没有得到适当解决。参考Al及Al合金的二元及三元相图,在Al-8.5Si-20Cu-10Ge钎料的基础上添加不同含量的稀土元素Sc作为研究对象,探究了合金元素对钎料合金熔化温度,铺展性能,以及6063铝合金钎焊接头强度的影响,并通过扫描电镜(SEM)、能谱仪(EDS)等分析设备探究了添加Sc元素对合金组织以及物相组成的影响,主要研究结果如下：对熔炼钎料的组织分析发现,将Sc添加到Al-8.5Si-20Cu-10Ge钎料合金后以晶粒明显细化,A13Sc粒子可成为有效的非均质晶核,促进晶粒细化,Al3Sc粒子能有效地钉扎位错和亚晶界,稳定亚结构并强烈抑制合金的再结晶。当合金加入Sc元素后,钎焊接头剪切强度明显提升,当Sc为0.1wt%时,钎焊接头的剪切强度可以达到71.78MPa,相比不加稀土元素的钎焊接头强度提高了28.64%。在本课题的研究范围内,钎料的铺展面积随Sc含量的增加先上升后下降,当Sc为0.3wt%达到最高的844.25mm2,继续增加Sc,钎料铺展面积反而下降,在Sc含量0.5wt%时减小到721.96mm2。综合考虑钎料的液相线温度、铺展性能和机械性能,在试验研究范围内2号钎料Al-8.5Si-20Cu-10Ge-0.1Sc性能良好,金相组织细化程度高,具有良好的铺展性能,力学性能优良等特点,可以适用于6063Al合金等的真空钎焊。
[Abstract]:The brazing problem of 6000 series heat-treated Al alloy has been the focus of research at home and abroad because of the lack of low melting point solder with good comprehensive properties. The softening of the base metal has not been solved properly after brazing. The binary and ternary phase diagrams of Al and Al alloys are referred to. On the basis of Al-8.5Si-20Cu-10Ge solder, different contents of rare earth element SC were added as the research object, and the melting temperature and spreading properties of alloy elements to the brazing alloy were investigated. The effects of SC addition on the microstructure and phase composition of 6063 aluminum alloy brazed joints were investigated by means of scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The main results are as follows: the microstructure analysis of the melting solder shows that the grain size is obviously refined by adding SC to the Al-8.5Si-20Cu-10Ge brazing alloy. A13Sc particles can become effective heterogeneous nuclei and promote grain refinement. Al3Sc particles can effectively pin dislocations and subcrystalline boundaries. Stable substructure and strong inhibition of recrystallization of the alloy. The shear strength of brazed joint increased obviously when SC was added into the alloy, when SC was 0.1 wt%. The shear strength of brazed joint can reach 71.78 MPA, and the strength of brazed joint without rare earth element is increased by 28.64%. With the increase of SC content, the spreading area of the filler metal first increased and then decreased. When SC reached the highest 844.25mm ~ 2, the spreading area of the filler metal decreased. When SC content is 0.5 wt%, it is reduced to 721.96mm2.The liquid phase line temperature, spreading property and mechanical property of the solder are considered synthetically. In the range of experimental study, the Al-8.5Si-20Cu-10Ge-0.1Sc of No.2 brazing alloy has good properties, the metallographic structure is fine, and it has good spreading performance. It is suitable for vacuum brazing of 6063 Al alloy due to its excellent mechanical properties.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG425;TG454

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