摘要
随着汽车零部件、通讯和电子产品的发展,其对铝合金的导热性能提出更高的需求,因此急需开发新型高强韧高导热铝合金材料。通过金相显微镜、扫描电镜、涡流电导率仪和万能力学性能测试仪等研究了微量Ce添加对Al-Si-Fe铝合金的微观组织、导电导热性能以及力学性能的影响。结果表明,稀土Ce添加量少于0.05%时对组织没有明显细化,0.07%Ce可以细化铝合金的微观组织,减少二次枝晶臂间距,初生α-Al相由粗大的枝状晶转化成胞状晶。当Ce含量为0.07%时,合金中出现亮白色的块状Al11Ce3相和灰白色针片状β-Al5FeSi相。稀土Ce元素的添加能提高合金的导电和导热性能,当添加0.07%Ce时,合金的导电率和导热率达到最佳值,导电率为36.6%IACS,导热率为153.97 W/(m·K)。随着微量稀土Ce元素的添加,合金的抗拉强度与屈服强度整体变化不大,抗拉强度为144.5 MPa,屈服强度为89.7 MPa,但伸长率有所提升。当添加0.07%Ce时,合金伸长率为4.54%,比未添加Ce时提升26.1%,这是由于微量Ce没有对组织产生足够的细化效果来提高强度,而使共晶Si和富铁相变质与细化,故提高了合金的伸长率。
With the development of aluminium alloys for automotive,communications and electronic products,increasing demand has been put forward for improving the thermal conductivity of aluminium alloys.Thus,the development of aluminium alloy materials with high strength,toughness and high thermal conductivity is urgently needed.The effects of the microaddition of Ce on the microstructure,electrical and thermal conductivity,and mechanical properties of Al-Si-Fe aluminium alloys were investigated via OM,SEM and eddy current conductivity meter methods.The results show that when the addition amount of Ce is less than 0.05 wt.%,there is no significant grain refinement in the alloy.The addition of 0.07 wt.%Ce can refine the size of theα-Al,reduce the secondary dendrite arm spacing,and promote the transformation of primaryα-Al from a coarse dendritic structure to a cellular structure.A bright white block-like Al11Ce3 phase and gray needle-likeβ-Al5FeSi phase are observed in the alloy with 0.07 wt.%Ce addition.The addition of Ce can improve the conductivity and thermal conductivity of the alloy.With the addition of 0.07 wt.%Ce,the conductivity and thermal conductivity of the alloy reaches the optimal values of 36.6%IACS and 153.97 W/(m·K),respectively.With increasing addition of Ce,the tensile strength and yield strength of the alloy remain similar.The tensile strength and yield strength are 144.5 and 89.7 MPa,respectively,while the elongation increases.The elongation is 4.54%in the alloy with 0.07 wt.%Ce,which is 26.1%greater than that of the alloy without Ce.This is because the trace amount of Ce does not produce enough grain refinement effect on the microstructure to improve the strength.Ce causes the modification and refinement of eutectic Si and Fe-rich phases,thereby improving the elongation of the alloy.
作者
甘佰辉
赵愈亮
刘欢
何威想
熊藤芳
张猷锐
孙振忠
GAN Baihui;ZHAO Yuliang;LIU Huan;HE Weixiang;XIONG Tengfang;ZHANG Yourui;SUN Zhenzhong(School ofMechanical Engineering,Dongguan University ofTechnology,Dongguan 523808,China;Dongguan Luxshare Precision Industry Co.,Ltd.,Dongguan 523808,China)
出处
《铸造技术》
CAS
2024年第5期466-474,共9页
Foundry Technology
基金
国家自然科学基金(52104373)
广东省“创新强校工程”计划科研项目(2023KTSCX150)。
关键词
铝合金
稀土Ce
合金组织
导电导热性能
力学性能
aluminium alloy
rare earth Ce
microstructure
conductive and thermal conductivity
mechanical properties
