选区激光熔化成形Al-Si-Mg-Zr 合金的微观组织与力学性能  

Microstructure and Mechanical Properties of Al-Si-Mg-Zr AlloyFabricated by Selective Laser Melting

作　　者：宰春凤 耿遥祥[1] 罗金杰 于江 张志杰[1] 鞠洪博[1] 许俊华[1] ZAI Chunfeng;GENG Yaoxiang;LUO Jinjie;YU Jiang;ZHANG Zhijie;JU Hongbo;XU Junhua(School of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212003,China;Kunshan Guoli Electronic Technology Co.,Ltd.,Kunshan 215333,China)

机构地区：[1]江苏科技大学材料科学与工程学院,江苏镇江212003 [2]昆山国力电子科技股份有限公司,江苏昆山215333

出　　处：《铸造技术》2022年第11期975-983,共9页Foundry Technology

基　　金：国家自然科学基金(51801079,52001140)。

摘　　要：本文以高Mg含量Al-Si-Mg合金为基础,通过引入Zr作为晶粒细化剂,设计并制备了选区激光熔化(SLM)成形Al-8.0Si-2.56Mg-0.41Zr合金,系统研究了不同激光扫描速度对合金粉末成形性以及不同时效处理条件对SLM成形样品微观组织和力学性能的影响。结果表明,样品的SLM成形性良好,最大相对密度约为99.5%。样品由分布于熔池边界的细小等轴晶和熔池内部的柱状晶构成,样品的晶粒尺寸明显小于SLM成形Al-Si-Mg合金。成形态样品的硬度最大值为(173±2)HV。当时效温度≤200℃时,样品的Vickers硬度随时效温度的增加而逐渐增大;当时效温度≥250℃时,样品的硬度迅速降低。样品在150℃下的等温时效处理结果表明,随着时效时间的增加,样品的硬度和压缩屈服强度逐渐增大,当时效处理时间为12 h时,样品的硬度和压缩屈服强度具有最大值,分别为(194±2)HV和(512±4)MPa。Based on a high Mg-content Al-Si-Mg alloy,a Zr-modified Al-8.0Si-2.56Mg-0.41Zr alloy was designed and prepared by selective laser melting(SLM)in this paper.The effects of different laser scanning speeds on the formability of alloy powder and different aging treatment conditions on the microstructure and mechanical properties of SLM-formed samples were systematically studied.The results show that the alloy exhibits good SLM formability with a maximum relative density of approximately 99.5%.The sample is composed of fine equiaxed crystals distributed at the boundary of the molten pool and columnar crystals inside the molten pool.The grain size of the sample is significantly smaller than that of the selective laser melted Al-Si-Mg alloy.The maximum hardness of the SLM-formed samples is(173±2)HV.When the aging temperature is less than or equal to 200℃,the Vickers hardness of the sample increases with increasing aging temperature;when the aging temperature is over or equal to 250℃,the hardness of the sample decreases rapidly.The hardness and compressive yield strength of the sample gradually increase with prolonged aging time at 150℃.The sample after aging treatment at 150℃for 12 h shows the maximum hardness and compressive yield strength,which are(194±2)HV and(512±4)MPa,respectively.

关 键 词：选区激光熔化 Al-Si-Mg-Zr合金 热处理 显微组织 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程] TG166.3[金属学及工艺—金属材料]