摘要
CuCrZr合金具有优良的导热性和导电性,且兼具良好的力学性能,在航空航天、核反应堆部件等领域有着重要应用。对选区激光熔化(SLM)制备CuCrZr合金的成形性能进行了分析,主要考虑激光功率、扫描速度和扫描间距3个主要工艺参数对合金成形致密度、显微组织和显微硬度的影响。研究结果表明,SLM制备的CuCrZr合金孔隙主要以粉末未完全熔化和气孔为主,当体积能量密度升高时,孔隙类型逐渐由粉末未熔化向气孔转变。扫描间距为0.12 mm时合金致密度优于扫描间距为0.09 mm的合金,最佳工艺为激光功率360W,扫描速度800 mm/s,扫描间距0.12 mm和层厚0.03 mm,此时致密度可达99.30%,其体积能量密度为125 J/mm^(3)。合金组织呈大晶粒包围小晶粒的特征,晶粒形状不规则、随机分布,体现了SLM成形过程中不均匀温度场引起的晶粒生长的各向异性。不同构建方向上组织形貌差异明显,XY面以等轴晶为主,XZ面则出现大量沿构建方向生长的柱状晶。此外,工艺参数对SLM成形CuCrZr合金的显微硬度值影响不明显,致密度对硬度的影响更为显著。细小晶粒或细长晶粒聚集处的硬度值较高。SLM技术可以用于制备高性能CuCrZr合金,通过优化工艺参数可以获得高致密度、细小均匀的显微组织和高硬度。
The CuCrZr alloy possesses excellent thermal and electrical conductivity,as well as good mechanical properties,making it an important material for aerospace,nuclear reactor components,and other fields.This study analyzes the forming performance of CuCrZr alloy prepared by selective laser melting(SLM),focusing on the effects of three main process parameters—laser power,scanning speed,and scanning spacing—on the alloy’s density,microstructure,and microhardness.The research indicates that the pores in SLM-formed CuCrZr alloys are primarily caused by incomplete powder melting and gas pores.As the volumetric energy density increases,the pore type gradually transitions from powder melting incompleteness to gas pores.The alloy exhibits higher density when the scanning spacing is 0.12 mm compared to 0.09 mm.The optimal process parameters are 360 W laser power,800 mm/s scanning speed,0.12 mm scanning spacing,and 0.03 mm layer thickness,achieving a density of 99.30%with a volumetric energy density of 125 J/mm^(3).The microstructure of the alloy features large grains surrounding smaller grains, with irregular and randomly distributed grain shapes, reflecting the anisotropy of grain growth caused by the non-uniform temperature field during SLM forming. The microstructure morphology differs significantly in different building directions, with equiaxed grains dominating on the XY plane, while the XZ plane shows a large number of columnar grains growing along the building direction. Additionally, the process parameters have a minimal impact on the microhardness value of SLM-formed CuCrZr alloys, with density exerting a more significant influence on hardness. Higher hardness values are observed in areas with finer or elongated grain aggregation. SLM technology can be utilized to fabricate high-performance CuCrZr alloys, and optimizing process parameters can result in high density, fine and uniform microstructure, and high hardness.
作者
宋峻岭
李怀学
范宏举
刘鹏
SONG Junling;LI Huaixue;FAN Hongju;LIU Peng(AVIC Xinxiang Aviation Industry(Group)Co.,Ltd.,Xinxiang 453000,China;AVIC Manufacturing Technology Institute,Beijing 100024,China;Shandong Jianzhu University,School of Materials Science and Engineering,Ji'nan 250101,China)
出处
《电焊机》
2024年第7期12-19,共8页
Electric Welding Machine
基金
国家重点研发计划项目(2023YFB4604903)。
