Laser additive manufacturing of nickel-based superalloys: A review

Abstract

Nickel-based superalloys are critical materials for high-temperature components in core equipment, such as aerospace engines and gas turbines. In recent years, with the rapid advancement of metal additive manufacturing (AM) technologies, the fabrication of complex geometries using nickel-based superalloys has been successfully applied in modern engines and gas turbines. These components demonstrate significant advantages in integration, weight reduction, multifunctionality, and performance enhancement. However, due to the complex alloy composition and multiphase microstructure of nickel-based superalloys, the AM process is accompanied by intricate phase transformations and high thermal stresses. This often leads to defects, such as hot cracking—particularly in the vicinity of the molten pool. In addition, the rapid non-equilibrium solidification and repeated thermal cycles from layer-by-layer deposition result in complex microstructural evolution and phase transformations during both solidification and subsequent solid-state reactions. These factors significantly influence the strengthening and toughening behavior of the superalloys. Consequently, the comprehensive mechanical properties of additively manufactured nickel-based superalloys still lag behind those of their traditionally forged counterparts. This article reviews recent domestic and international research progress on the mechanisms of crack formation and control strategies in AM of nickel-based superalloys, as well as the evolution of microstructure and the associated strengthening and toughening mechanisms. Furthermore, it discusses the design of nickel-based superalloys tailored specifically for AM, and offers insights and future perspectives on the development of advanced strengthening strategies and alloy design methodologies for AM applications.

Keywords

Additive manufacturing / Nickel-based superalloy / Cracking mechanism / Microstructural evolution / Strengthening mechanism / Alloy design

Funding

This work was supported by the Advanced Materials- National Science and Technology Major Project (Grant No. 2024ZD0601000), National Natural Science Foundation of China (Grant No. 52105344), Natural Science Foundation of Guangdong Province (Grant No. 2021A1515010942), and Guangzhou Basic and Applied Basic Research (Grant No. 202201010365).

Conflict of Interest

The authors declare no financial or personal relationships with other people or organizations that can inappropriately influence the present work. There is no professional or other personal interest of any nature or kind in any product, service, or company that could be construed as influencing the work presented in, or the review of, the present article.

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