后处理工艺对一种激光增材制造镍基高温合金组织与性能的影响

Influence of Post-Treatment Process on Microstructure and Properties of Laser Additively Manufactured Nickel-Based Superalloy

摘要:

在激光增材制造过程中，镍基高温合金存在裂纹和微孔等缺陷，阻碍其在各领域应用。将热等静压（HIP）与传统热处理（HT）相结合，以获得缺陷少且性能理想的激光粉末床熔融（LPBF）镍基高温合金零件。结果表明，HIP工艺提高致密度，传统HT改善显微缺陷并提高力学性能。经HIP处理后，LPBF试样缺陷体积分数下降，经HT处理后，HIP+HT缺陷含量略有上升。经后处理后，硬度呈下降趋势，室温下，HIP+HT试样的抗拉伸强度和断后伸长率分别提高到1326 MPa和21.3%。

关键词:镍基高温合金;激光粉末床熔融;后处理;组织;性能

Abstract:

Defects such as cracks and micropores exist in nickel-based superalloy during laser powder bed fusion (LPBF), hindering their application in various fields. Hot isostatic pressing (HIP) was combined with conventional heat treatment (HT) to obtain LPBF nickel-based superalloy parts with ideal properties and fewer defects. The results show that HIP process can improve the densification, while the conventional HT can eliminate the micro-defects to improve the mechanical properties. After HIP treatment, the defect volume fraction of LPBF specimens decreases. After HT, the defect content of HIP+HT specimens increases slightly. After post-treatment, the hardness shows a decreasing trend, and the tensile strength and post-break elongation of HIP+HT specimens increase to 1326 MPa and 21.3%, respectively, at room temperature.

Key words:nickel-based superalloy;laser powder bed fusion;post-treatment;microstructure;properties