稀土La、Ce和Y对Al-6.5Si-5.5Cu-0.2Zr-0.01Sr-0.06Ti-0.2RE合金组织和力学性能的影响  

Effects of Rare Earth La,Ce and Y on Microstructure and Mechanical Properties of Al-6.5Si-5.5Cu-0.2Zr-0.01Sr-0.06Ti-0.2RE Alloy

作　　者：刘乐乐 孙智伟 许晓静[1] 洪志恒 LIU Lele;SUN Zhiwei;XU Xiaojing;HONG Zhiheng(Institute of Advanced Manufacturing and Modern Equipment Technology,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]江苏大学先进制造与现代装备技术工程研究院,江苏镇江212013

出　　处：《热加工工艺》2024年第19期132-137,共6页Hot Working Technology

基　　金：镇江市重点研发计划项目(SGY20180110115)。

摘　　要：通过SEM、OM、EDS、拉伸试验,研究了稀土La、Ce和Y对Al-6.5Si-5.5Cu-0.2Zr-0.01Sr-0.06Ti-0.2RE铸态合金组织以及力学性能的影响。结果表明:稀土元素Ce和Y明显改善了合金的微观组织,细化了α-Al相,并且提高了共晶Si相的变质效果,而La元素对合金的改善效果较差。加入稀土元素Ce和Y的铸态合金具有较高的力学性能,硬度分别为76.8 HV和79.05 HV,抗拉强度分别为182.61 MPa和216.83 MPa,断后伸长率分别为6.03%和7.84%。而具有La元素的铸态合金的力学性能较低,硬度为73.58 HV,抗拉强度为160.58 MPa,断后伸长率为3.21%。具有稀土元素La的铸态合金的抗晶间腐蚀性能较好,腐蚀坑较小,最大腐蚀深度达90μm,腐蚀等级为三级。而具有稀土元素Ce和Y的铸态合金的抗晶间腐蚀性逐渐变差,最大腐蚀深度分别为110.21μm和145.68μm。The effects of rare earth La,Ce and Y on the microstructure and mechanical properties of Al-6.5Si-5.5Cu-0.2Zr-0.01Sr-0.06Ti-0.2RE as-cast alloy were studied by SEM,OM,EDS and tensile test.The results show that the rare earth elements Ce and Y significantly improve the microstructure of the alloy,refine theα-Al phase,and improve the modification effect of the eutectic Si phase,while the improvement effect of La element is poor.The as cast alloys with rare earth elements Ce and Y have high mechanical properties,and the hardness is 76.8 HV and 79.05 HV,respectively,the tensile strength is 182.61 MPa and 216.83 MPa,and the elongation after fracture is 6.03%and 7.84%,respectively.The mechanical properties of the as-cast alloy with La element are lower,the hardness is 73.58 HV,the tensile strength is 160.58 MPa,and the elongation after fracture is 3.21%.The as-cast alloy with rare earth element La has better resistance to intergranular corrosion,smaller corrosion pits,maximum corrosion depth of 90μm,and corrosion grade of three.However,the intergranular corrosion resistance of the as-cast alloys with rare earth elements Ce and Y gradually deteriorates,and the maximum corrosion depths are 110.21μm and 145.68μm,respectively.

关 键 词：AL-SI-CU合金 稀土 微观组织 力学性能 

分 类 号：TG292[金属学及工艺—铸造]