粉末循环使用对激光选区熔化GH4169合金组织及拉伸行为的影响(特邀)  

Effect of Powder Recycling on Microstructure and Tensile Behavior of GH4169 Alloy Fabricated by Selective Laser Melting(Invited)

作　　者：宋巍 朱玉平 梁静静[1] 周亦胄[1] 孙晓峰[1] 李金国[1] Song Wei;Zhu Yuping;Liang Jingjing;Zhou Yizhou;Sun Xiaofeng;Li Jinguo(ShiChangxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,Liaoning,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,Liaoning,China)

机构地区：[1]中国科学院金属研究所师昌绪先进材料创新中心,辽宁沈阳110016 [2]中国科学技术大学材料科学与工程学院,辽宁沈阳110016

出　　处：《中国激光》2024年第10期163-177,共15页Chinese Journal of Lasers

基　　金：国防工业技术发展计划基金(JCKY2020130C024);国家重点研发计划(2021YFB3702503);科学中心燃气轮机项目(P2022-C-Ⅳ-002-001);国家科技重大专项(Y2019-Ⅶ-0011-0151)

摘　　要：激光选区熔化GH4169合金粉末的循环使用可以显著降低制备成本、缩短生产周期。但是,利用循环使用的合金粉末,通过激光选区熔化技术成形的部件在组织、缺陷、性能行为上均存在差异。研究了不同循环使用次数下GH4169合金粉末的组织、缺陷及粒径分布等特征对成形件热处理态组织和相分布、拉伸行为及变形机制的影响。分析了循环使用后的粉末形貌和粒径分布、热处理试样的断口形貌、断口纵剖面组织和断口附近透射组织特征,详细阐述了拉伸断裂方式和强韧化机制。结果表明:粉末多次循环使用后平均粒径由30.45μm逐渐增大至41.80μm;表面愈加粗糙,流动性由14.85 s/50 g增加到18.62 s/50 g,较差的流动性导致热处理试样出现孔洞缺陷;合金拉伸强度(50~100 MPa)下降,力学性能受损;而断裂方式和变形机制不受影响。热处理态合金析出了纳米尺寸的块状碳化物、短棒状δ相、Laves相以及γ″和γ′强化相,拉伸过程中有效的钉扎位错提升了合金性能,使合金在室温和650℃下的最大抗拉强度分别达到1430 MPa和1205 MPa,优于或接近已报道的锻造、铸造和增材制造GH4169合金。研究结果为激光选区熔化GH4169合金的粉末循环使用和拉伸变形机制分析提供了参考。Objective GH4169 superalloys are widely used in aerospace engines and other hightemperature components.Powder recycling of the GH4169 alloy during selective laser melting(SLM)can significantly reduce the preparation cost and shorten production cycles.However,the components formed by the SLM using recycled alloy powders exhibit differences in microstructural defects and performance behavior because of changes in the size distribution,shape,uniformity,and composition of the powders.This study investigates the effects of the microstructure,defects,and particle size distribution of GH4169 alloy powders after different recycling times on the microstructure,phase distribution,tensile behavior,and deformation mechanism of formed parts in a heattreated state.Methods The GH4169 alloy powder prepared via argon atomization is used in the SLM forming process.The powder is printed and reused for 0‒13 times without adding the newly prepared powder.The largesized inclusions and support residues are removed by using a 100μm powder sieve.The specimens are defined as 0th,6th,10th,and 13th specimens,according to the number of times the powder is recycled,as shown in Table 1.The 0th,6th,10th,and 13th specimens are heattreated after SLM formation,using the heattreatment schedule shown in Table 2.Finally,after sample preparation and polishing,scanning electron microscope(SEM)and transmission electron microscope(TEM)photographic analyses are performed.Results and Discussions After multiple powder recyclings,the powder still exhibits good overall degree of sphericity,but the powder morphology changes with an increase in the usage time.The number of defective powders,such as satellite powder and irregular particles,is relatively small among powders with fewer recycling times(0 and 6),as indicated by the powder particles marked by the dashed circle in Fig.1.However,as the recycling time gradually increases,the number of satellite balls in the powder significantly increases in the 10th and 13th samples.Some particles even have 2 or 3 la

关 键 词：增材制造 激光选区熔化 GH4169合金 粉末特性 组织演变 拉伸行为 

分 类 号：TH164[机械工程—机械制造及自动化]