送粉式激光增材制造Al-Mg-Sc-Zr合金的微观组织与力学性能  

Microstructure and mechanical properties of Al-Mg-Sc-Zr alloy by powder feeding laser additive manufacturing

作　　者：林泽桓 李瑞迪[1] 祝弘滨 袁铁锤[1] 徐荣 闫华[3] 叶兵 LIN Zehuan;LI Ruidi;ZHU Hongbin;YUAN Tiechui;XU Rong;YAN Hua;YE Bing(State key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;CRRC Industrial Research Institute,Beijing 100000,China;College of Materials Engineering,Shanghai University of Engineering Science,Shanghai 201620,China;Wuhan Huagong Laser Engineering Co.Ltd.,Wuhan 215000,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083 [2]中车工业研究院有限公司,北京100000 [3]上海工程技术大学材料工程学院,上海201620 [4]武汉华工激光工程有限责任公司,湖北武汉215000

出　　处：《中南大学学报（自然科学版）》2020年第11期3055-3063,共9页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51871249);湖南省自然科学基金资助项目(2020JJ2046)。

摘　　要：采用送粉式激光增材制造方法制备Al-Mg-Sc-Zr合金试样,采用金相显微镜、X射线衍射分析、扫描电子显微镜、室温拉伸试验及显微硬度测量等手段研究送粉式激光增材制造Al-Mg-Sc-Zr合金时效前后的微观组织与力学性能。研究结果表明:打印态试样熔池边界附近存在细晶区,而熔池内部发现粗大的树枝胞状晶粒,粒径约为7μm。试样拉伸强度(σuts)为(303.72±4.00)MPa,屈服强度(σ0.2)为(216.93±3.00)MPa,伸长率(εf)为7.65%±0.34%。试样XOZ面、XOY面和YOZ面的硬度(HV)分别为112.29±6.00,85.76±1.70和90.176±5.340。在325℃/4 h时效处理后,熔池边界附近晶粒发生了一定程度的长大,导致熔池边缘开始消失,但熔池内部晶粒尺寸和形状没有变化。试样拉伸性能有较为明显的提升,抗拉强度提升到(318.13±5.00)MPa,屈服强度提升到(234.84±1.90)MPa,而伸长率下降到6.96%±0.24%。试样XOZ面、XOY面和YOZ面的硬度(HV)分别提升到118.75±4.00,88.60±0.93和101.44±2.75。Al-Mg-Sc-Zr alloy samples were prepared by powder feeding laser additive manufacturing method.And microstructure and mechanical properties of Al-Mg-Sc-Zr alloy were studied by means of metallographic microscope,X-ray diffraction analysis,scanning electron microscope,room temperature tensile test and microhardness measurement,etc.The results show that for the printed samples,fine grains are found on the boundary of the pools.And large dendritic cell grains with the size of about 7μm exist inside the pools.The tensile strength(σuts)is(303.72±4.00)MPa,yield strength(σ0.2)is(216.93±3.00)MPa,and elongation(εf)is 7.65%±0.34%.The hardness on XOZ-plane,XOY-plane and YOZ-plane of the sample are 112.29±6.00,85.76±1.70 and 90.176±5.340,respectively.After aging treatment at 325℃for 4 h,the grain size at the edge of the pool grows to a certain extent,leading to the disappearance of the edge of the pool,but the grain size and shape inside the pool do not change.Tensile strength increases to(318.13±5.00)MPa,yield strength increases to(234.84±1.90)MPa,and elongation decreases to 6.96%±0.24%.The hardness on XOZ-plane,XOY-plane and YOZ-plane of the sample increase to 118.75±4.00,88.60±0.93 and 101.44±2.75,respectively.

关 键 词：激光送粉增材制造 铝钪合金 时效处理 微观组织 拉伸性能 显微硬度 

分 类 号：TG146.21[一般工业技术—材料科学与工程]