均匀化处理对激光选区熔化GH3536和GH4169合金组织和显微硬度的影响  

Effect of homogenizing treatment on microstructure and microhardness of GH3536 and GH4169 alloy by selective laser melting

作　　者：耿硕 张冬云[1,2] 李健民 仪登豪 池煜璟 黄帅 张学军 GENG Shuo;ZHANG Dongyun;LI Jianmin;YI Denghao;CHI Yujing;HUANG Shuai;ZHANG Xuejun(School of Physics and Optoelectronic Engineering,Beijing University of Technology,Beijing 100124,China;Beijing Engineering Research Center of 3D Printing for Digital Medical Health,Beijing 100124,China;AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]北京工业大学物理与光电工程学院,北京100124 [2]北京市数字化医疗3D打印工程技术研究中心,北京100124 [3]中国航发北京航空材料研究院,北京100095

出　　处：《航空材料学报》2024年第1期72-83,共12页Journal of Aeronautical Materials

基　　金：中国航空发动机集团产学研合作项目(HFZL2021CXY020)。

摘　　要：GH3536和GH4169镍基高温合金常用来制造航空发动机等热端部件。采用激光选区熔化(selective laser melting,SLM)最优工艺参数制备GH3536和GH4169合金试样,研究不同均匀化温度和保温时间对两种合金组织演变、平均晶粒尺寸和性能的影响,利用OM、SEM、EDS等方法表征其缺陷特征和微观组织,利用维氏硬度仪测试合金的显微硬度。结果表明:成形态GH3536合金中存在更多缺陷,包括气孔、裂纹和未熔合;成形态GH4169合金中只存在气孔。均匀化处理使合金熔池消失,使晶粒长大成为等轴晶。GH3536合金晶界和晶内有M_(23)C_(6)析出,GH4169合金晶界和晶内有NbC析出,随着均匀化温度升高,析出物明显减少。GH3536合金的平均晶粒尺寸从1130℃,1 h的48.5μm增大到1250℃,4 h的100.9μm,增大了106.8%;GH4169的平均晶粒尺寸从1080℃,1 h时的57μm增大到1200℃,4 h时的87.4μm,增加了53.3%。GH3536合金经过均匀化处理后显微硬度下降明显,由原来262HV下降到180~190HV;与之相反,GH4169合金经过均匀化处理后硬度提高,显微硬度均保持在430~450HV之间,明显高于成形态试样的313HV。GH3536 and GH4169 nickel-based superalloys are widely used in aerospace engines and other hot-end components.In this paper,GH3536 and GH4169 alloy samples were fabricated by optimizing the process parameters using selective laser melting(SLM),the defect characteristics and microstructure of two alloys,as well as the effects of different homogenization temperatures and holding times on microstructure evolution,average grain size,and properties of two alloys were studied.The defect characteristics and microstructure were investigated by OM,SEM,and EDS,et al.The Vickers hardness meter was used to test the alloy’s microhardness.The results indicate that the as-built GH3536 alloy exhibits more defects,including pores,cracks,and lack of fusion,while only pores are present in as-built GH4169 alloy.The melt pool of alloy is eliminated by homogenization treatment,and the grains grow into equiaxed grains.M_(23)C_(6)are found to distribute within grain boundaries and grain interiors of GH3536 alloy,while NbC are found to distribute within grain boundaries and grain interiors of GH4169 alloy,and the amount of precipitates is significantly reduced with the increase of homogenization temperature.The average grain size of GH3536 alloy is increased by 106.8%from 48.5μm at 1130℃/1 h to 100.9μm at 1250℃/4 h.The grain size of GH4169 alloy is increased by 53.3%from 57μm at 1080℃/1 h to 87.4μm at 1200℃/4 h.The homogenization treatment of GH3536 alloy and GH4169 alloy results in a significant decrease in microhardness of the former,from 262HV to 180-190HV,while the latter shows a significant increase,from 313HV to 430-450HV.

关 键 词：激光选区熔化 GH3536 GH4169 微观组织 均匀化热处理 平均晶粒尺寸 显微硬度 

分 类 号：V252[一般工业技术—材料科学与工程] TG146.1[航空宇航科学与技术—航空宇航制造工程]