激光选区熔化GH3536镍基高温合金组织与性能研究  

Microstructure and Properties of GH3536 Nickel-Based Superalloys by Selective Laser Melting

作　　者：陈楠 李瑞迪 袁铁锤 张毅 马鑫 黄敏 Chen Nan;Li Ruidi;Yuan Tiechui;Zhang Yi;Ma Xin;Huang Min(State Key Laboratory of Powder Metallurgy,Powder Metallurgy Research Institute,Central South University,Changsha 410083,China;AECC South Industry Company Limited,Zhuzhou 412002,China)

机构地区：[1]中南大学粉末冶金研究院粉末冶金国家重点实验室,湖南长沙410083 [2]中国航发南方工业有限公司,湖南株洲412002

出　　处：《稀有金属》2023年第5期679-691,共13页Chinese Journal of Rare Metals

基　　金：高新技术产业科技创新引领计划项目(2020GK2031);湖南省自然科学基金项目(2020JJ2046)资助。

摘　　要：研究了激光选区熔化(SLM)GH3536合金扫描面与建造面的组织与性能。采用光学显微镜(OM)、 X射线衍射仪(XRD)、扫描电镜(SEM)和电子背散射衍射(EBSD)对激光选区熔化GH3536合金金相、物相、微观组织和晶粒特征进行研究。结果表明,通过优化成形参数可以减少合金中孔隙与微裂纹,但是无法消除。半椭圆形熔池广泛分布于建造面,其宽深比约为1.5。激光选区熔化GH3536合金由单一的面心立方γ奥氏体组成。扫描面与建造面都分布着大量胞状与柱状亚晶,建造面熔池交界处存在沿建造方向的微裂纹。建造面的平均晶粒尺寸(145.1μm)约为扫描面晶粒尺寸的4.5倍,织构强度约为扫描面的2倍。横向与纵向试样的拉伸性能存在明显差异,横向试样的屈服强度和极限抗拉强度分别为645 MPa和781 MPa,分别比纵向试样高4.1%和7.0%。激光选区熔化GH3536合金断口呈明显韧性断裂,存在大量韧窝。本研究有望为激光选区熔化GH3536合金扫描面与建造面组织与性能差异提供有效的参考。GH3536 superalloy was prepared by selective laser melting(SLM)and the effect of forming parameters on the superalloy microstructure was studied in this paper.The difference in microstructures and properties between the scanning plane and the building plane was studied.The metallographic,phase,microstructure and grain characteristics of SLMed GH3536 alloy were studied by optical microscope(OM),X-ray diffractometer(XRD),scanning electron microscope(SEM)and electron backscattered diffraction(EBSD).The pores and microcracks could be reduced by optimizing the forming parameters,but could not be eliminated.The forming parameters of SLM played a decisive role in the internal defects of GH3536 superalloy according to the types and quantities of defects.The forming parameter interval could be divided into three regions.When the energy density reached a low level,many irregularly shaped unfused pores and a large number of tiny pores could be observed.The keyholes were formed when the energy density reached a high enough level.By optimizing the process parameters of SLMed GH3536 superalloy,the optimal forming parameters were finally obtained:laser power(P)=200 W,scanning speed(v)=800 mm·s^(-1),hatch spacing(h)=0.08 mm,layer thickness(t)=0.03 mm.GH3536 alloy consisted of a single face-centered cubicγaustenite.Due to its high solidification rate(1×10^(4)~1×10^(6) K·s^(-1))and the phenomenon of"solute capture"caused by rapid solidification,the precipitation phase cooled to form a supersaturated solid solution before it precipitated.Most of the alloying elements were solid-dissolved into the nickel matrix to form a singleγaustenite.However,there were significant differences in the organizational preference orientation between the scanning planes and building planes.The scanning plane had the strongest diffraction peak at 74.5°,indicating that its texture grew along(220)crystal plane.While the building plane had the strongest diffraction peak at(200),indicating that GH3536 alloy had a 002 fibrous texture on the building p

关 键 词：镍基高温合金 激光选区熔化(SLM) 显微组织 力学性能 

分 类 号：TG146.1[一般工业技术—材料科学与工程]