微量In对Al-Si-Cu合金析出行为的影响  

Effects of Trace In on Precipitation Behavior of AI-Si-Cu Alloys

作　　者：朱慧颖 翁文凭 王东涛 长海博文 蔡伟涛 罗广瑞 Zhu Huiying;Weng Wenping;Wang Dongtao;Hiromi Nagaumi;Cai Weitao;Luo Guangru(Schoolof Iron and Steel,Soochow University)

机构地区：[1]苏州大学沙钢钢铁学院,江苏苏州215000

出　　处：《特种铸造及有色合金》2023年第9期1270-1275,共6页Special Casting & Nonferrous Alloys

摘　　要：通过扫描电镜(SEM)、透射电镜(TEM)、显微硬度和电导率等方法探讨了0.4%的In对Al-7Si-3Cu合金的沉淀析出行为及组织性能的影响。结果表明,0.4%的In促进了Al-7Si-3Cu合金的时效析出过程,并显著细化了θ′相。当添加0.4%的In时,合金达到峰值硬度的时效时间显著缩短,硬度(HV)在160℃时效16 h处达到峰值127,而未添加In的合金在同等时效温度下30 h仍未达到峰值,硬度(HV)仅为88。进一步采用DSC分析,结果发现,微量In显著降低θ′相反应激活能,与未添加In的合金相比,含In合金中θ′相的反应激活能从36.839 kJ/mol降低至28.591 kJ/mol,反应难度显著降低,达到促进析出的效果。TEM结果也表明,含In合金中θ′相析出物数量密度更高且更加细小。由此可见,微量In对Al-7Si-3Cu合金的时效析出过程及组织结构的影响,有益于提高合金的力学性能和电导率。The influence of 0.4%In on precipitation behavior,microstructure and properties of Al-7Si-3Cu alloy was investigated by scanning electron microscopy(SEM),transmission electron microscopy(TEM),microhardness and electrical conductivity experiments.The results indicate that O.4%In promotes the aging precipitation process of Al-7Si-3Cu alloy and significantly refinesθ′phase.After 0.4%In addition,the aging time to reach peak hardness of the alloy is obviously shortened,which reaches a peak of 127 HV after aging at 160 C for 16 h,while In-free alloy fails to reach peak at the same aging temperature for 30 h,with the hardness of 88 HV.DSC curves reveal that trace In can significantly reduce the reaction activation energy ofθ′phase,which is reduced from 36.839 kJ/mol to 28.591 kJ/mol compared with that of In-free alloy,indicating the reduction of reaction difficulty,achieving the effect of promoting precipitation.TEM results also demonstrate that the quantity density of oθ′phase precipitates in In-containing alloys is larger and finer.In conclusion,the effects of trace In on aging precipitation process and the microstructure are beneficial to improve the mechanical properties and conductivity of Al-7Si-3Cualloy.

关 键 词：Al-Si-Cu微合金化 In 人工时效 组织性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]