激光重熔对选区激光熔化成形AlSi10Mg合金的缺陷控制及组织性能研究  

Defect Control and Microstructure Properties of AlSi10Mg Alloy Formed by Selective Laser Melting with Laser Remelting

作　　者：于天硕 韩永全 YU Tianshuo;HAN Yongquan(Jilin Vocational College of Industry and Technology,Jinlin Jilin 132000,China;Inner Mongolia University of Science&Technology,Inner Mongolia Baotou 014000,China)

机构地区：[1]吉林工业职业技术学院,吉林吉林132000 [2]内蒙古科技大学,内蒙古包头014000

出　　处：《精密成形工程》2025年第2期44-51,共8页Journal of Netshape Forming Engineering

基　　金：内蒙古自治区自然科学基金(2022ZD03);装备预先研究领域基金(80923010302);内蒙古自治区自然科学一般项目(NJZY22119);吉林工业职业技术学院科技重点项目(24KY01KJZ)。

摘　　要：目的通过激光重熔解决选区激光熔化(SLM)成形过程中因AlSi10Mg合金激光反射率高、密度小而造成试样成形质量差的问题。方法基于重熔扫描在SLM过程中的独特优势,系统研究激光重熔前后试样成形质量、组织性能的异同。结合未熔粉末、气孔等缺陷数量,对SLM成形试样进行内部缺陷分析;结合物相、晶粒形态及织构等微观结构,分析激光重熔前后内部组织的异同;结合拉伸性能、显微硬度等力学性能,分析重熔扫描对SLM成形试样的强化机制。结果在缺陷控制方面,激光重熔消除了样品中的未熔粉末,降低了气孔的数量密度,提高了相对密度;在微观组织方面,激光重熔后临界形核过冷度的减小促进了形核,导致熔池内部分柱状晶转化为等轴晶,使晶粒尺寸大大降低,同时重熔过程中的二次熔化使热流累积效应增强,晶粒织构增强;在力学性能方面,通过霍尔佩奇效应、晶粒细化显著提高了抗拉强度和显微硬度,最终得到了内部缺陷较少、晶粒细小且性能较为优异的AlSi10Mg合金SLM试样。结论激光重熔技术可以有效解决SLM成形AlSi10Mg合金试样质量差的问题,重熔后的试样晶粒细小,各项性能较为优异。The work aims to solve the problem of poor sample forming quality caused by the high laser reflectivity and low density of AlSi10Mg alloy during the selective laser melting(SLM)forming process through laser remelting.Based on the unique advantages of remelting scanning in the SLM process,a systematic study was conducted on the differences and similari-ties in the forming quality and microstructure properties of samples before and after laser remelting.The internal defects of SLM formed samples were analyzed based on the number of defects such as unmelted powder and pores;The similarities and differ-ences in the internal structure before and after laser remelting were analyzed by combining microstructure such as phase,grain morphology,and texture;The strengthening mechanism of SLM formed samples was analyzed by remelting scanning based on mechanical properties such as tensile properties and microhardness.The results showed that laser remelting eliminated unmelted powder in the sample,reduced the number and density of pores,and improved the relative density in defect control;In terms of microstructure,it was found that the decrease in critical nucleation undercooling after laser remelting promoted the occurrence of nucleation events,leading to the transformation of columnar crystals into equiaxed crystals inside the melt pool,greatly re-ducing grain size.At the same time,the secondary melting during the remelting process enhanced the heat flux accumulation ef-fect and grain texture;In terms of mechanical properties,it was found that through the Hall Page effect,grain refinement signif-icantly improved tensile strength and microhardness,resulting in AlSi10Mg alloy SLM samples with fewer internal defects,smaller grains,and better performance.In conclusion,laser remelting technology can effectively solve the problem of poor qual-ity of AlSi10Mg alloy samples formed by SLM.The remelted samples have small grains and excellent properties.

关 键 词：激光重熔 选区激光熔化 AlSi10Mg合金 组织性能 

分 类 号：TG4[金属学及工艺—焊接]