激光粉末床熔融镍基高温合金开裂行为研究  

Study on the Cracking Behaviour of Nickel-based Superalloys via Laser Powder Bed Fusion

作　　者：李鑫 程向 胡鹏飞 刘壮壮 LI Xin;CHENG Xiang;HU Pengfei;LIU Zhuangzhuang(Key Laboratory for Advanced Materials Processing(MOE),Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China;Beijing Laboratory of Metallic Materials and Processing for Modern Transportation,Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学新材料技术研究院材料先进制备技术教育部重点实验室,北京100083 [2]北京科技大学新材料技术研究院现代交通金属材料与加工技术北京实验室,北京100083

出　　处：《铸造技术》2024年第8期763-771,共9页Foundry Technology

基　　金：国家重点研发计划(2022YFB4600302);国家自然科学基金(No.52104368)。

摘　　要：增材制造专用镍基高温合金研发需要经历成分设计-制粉-打印-表征,该过程周期长、成本高,严重限制了增材制造用新型合金的快速研发和应用。针对这一问题,本文提出以激光扫描合金块体材料评价其粉末材料打印性的思路,避免成分设计过程多次制粉。以4种典型镍基高温合金(Inconel 718,Hastelloy X,CM247LC,Inconel 939)为研究对象,采用激光扫描合金粉体和块体材料,研究不同合金在激光扫描其粉体和块体过程中的开裂关联性。结果表明,裂纹敏感性低的Inconel 718合金,激光扫描粉体和块体试样中均未发现裂纹;裂纹敏感性高的CM247LC和Inconel 939合金,激光扫描粉体试样中存在由于凝固末期枝晶间液相补给不足,在热收缩拉应力下形成的凝固裂纹和热循环过程残余应力导致的固态裂纹,而激光扫描块体试样中仅存在凝固裂纹,表明两种状态试样裂纹类型不同,但开裂趋势一致;裂纹敏感性介于上述合金之间的Hastelloy X合金,激光扫描粉体试样可在一定工艺窗口范围内实现无裂纹,而激光扫描块体试样时,在本文采用的所有参数下均存在裂纹,两种状态试样开裂趋势存在差异,但均为凝固裂纹。The research and development of nickel-based superalloys specifically for additive manufacturing involves a lengthy and costly process of composition design,powder production,printing,and characterization.This significantly hinders the rapid development and application of new alloys for additive manufacturing.To address this issue,this paper proposed evaluating the printability of alloy powders by laser scanning ingot materials,thereby avoiding multiple powder productions during the composition design process.Focusing on four typical nickel-based superalloys(Inconel 718,Hastelloy X,CM247LC,and Inconel 939),the correlation of cracking in both alloy powders and ingot materials during laser scanning was investigated.The results indicate that for the low crack sensitivity Inconel 718 alloy,no cracks are observed in either the laser-scanned powder or the ingot samples.In contrast,the high crack sensitivity alloys CM247LC and Inconel 939 exhibit solidification cracks in the laser-scanned powder samples due to insufficient interdendritic liquid phase feeding at the end of solidification under thermal contraction tensile stress and solid-state cracks due to residual stress during thermal cycling.However,only solidification cracks are found in the laser-scanned ingot samples,indicating that the types of cracks differ between the two states,but the cracking trends are consistent.For the Hastelloy X alloy,which has intermediate crack sensitivity,crack-free laser-scanned powder samples can be obtained within a certain process window,whereas all the parameters used for the laser-scanned ingot samples result in cracks,showing differences in cracking trends between the two states but with both exhibiting solidification cracks.These findings suggest that analysing the cracking behavior of laser-scanned ingot alloy materials provides a reference for understanding the cracking behavior of the corresponding alloy powders during laser powder bed fusion(L-PBF)formation.

关 键 词：镍基高温合金 激光粉末床熔融 铸造 开裂行为 

分 类 号：TG146.15[一般工业技术—材料科学与工程]