Alloy design for laser powder bed fusion additive manufacturing: a critical review

• Published in: International Journal of Extreme Manufacturing Vol. 6; no. 2; pp. 22002 - 62
• Main Authors: Liu, Zhuangzhuang, Zhou, Qihang, Liang, Xiaokang, Wang, Xiebin, Li, Guichuan, Vanmeensel, Kim, Xie, Jianxin
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.04.2024; Beijing Advanced Innovation Center for Materials Genome Engineering,University of Science and Technology Beijing,Beijing 100083,People's Republic of China; Key Laboratory for Advanced Materials Processing(MOE),Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,People's Republic of 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,People's Republic of China%Key Laboratory for Advanced Materials Processing(MOE),Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,People's Republic of China%Capital Aerospace Machinery Corporation Limited,Beijing 100076,People's Republic of China%Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education),Shandong University,Jingshi Road 17923,Jinan 250061,People's Republic of China%Department of Materials Engineering,KU Leuven,Leuven 3001,Belgium
• Subjects: Additive manufacturing; alloy design; Alloy development; Alloy powders; Alloys; Cooling rate; crack mitigation; Heat treating; Heat treatment; Iron; Laser beam welding; laser powder bed fusion; Machine learning; Manufacturing; Powder beds; printability; Rapid solidification; Titanium base alloys; Weldability; alloy design; crack mitigation; printability; laser powder bed fusion
• ISSN: 2631-8644; 2631-7990
• DOI: 10.1088/2631-7990/ad1657

Metal additive manufacturing (AM) has been extensively studied in recent decades. Despite the significant progress achieved in manufacturing complex shapes and structures, challenges such as severe cracking when using existing alloys for laser powder bed fusion (L-PBF) AM have persisted. These challenges arise because commercial alloys are primarily designed for conventional casting or forging processes, overlooking the fast cooling rates, steep temperature gradients and multiple thermal cycles of L-PBF. To address this, there is an urgent need to develop novel alloys specifically tailored for L-PBF technologies. This review provides a comprehensive summary of the strategies employed in alloy design for L-PBF. It aims to guide future research on designing novel alloys dedicated to L-PBF instead of adapting existing alloys. The review begins by discussing the features of the L-PBF processes, focusing on rapid solidification and intrinsic heat treatment. Next, the printability of the four main existing alloys (Fe-, Ni-, Al- and Ti-based alloys) is critically assessed, with a comparison of their conventional weldability. It was found that the weldability criteria are not always applicable in estimating printability. Furthermore, the review presents recent advances in alloy development and associated strategies, categorizing them into crack mitigation-oriented, microstructure manipulation-oriented and machine learning-assisted approaches. Lastly, an outlook and suggestions are given to highlight the issues that need to be addressed in future work. Process features and typical defects of L-PBF are summarized. Printability of Fe-based, Ni-based, Al-based and Ti-based alloys is summarized and discussed. The application of weldability criteria in assessing printability during L-PBF for each alloy is evaluated. Strategies used in alloy design for L-PBF are summarized and categorized into crack mitigation-oriented, microstructure manipulation-oriented and machine learning-assisted approaches.