Advances in laser powder bed fusion of hard-to-weld superalloys: a comprehensive review

• Comprehensively reviews characteristics of laser powder bed fusion formed hard-to-weld superalloys. • Outlines microstructural features and defect types. • Summarize approaches for microstructural control and defect inhibition. • Shortcomings of conventional process parameters and heat treatment optimization. • Proposes innovative strategies to overcome current constraints. The aerospace industry’s demand for superalloys with superior oxidation and hot corrosion resistance has spurred the development of advanced materials for hot-end components. However, traditional manufacturing techniques such as forging and casting, encounter significant challenges due to the complex compositions of these alloys, often leading to processing difficulties and inadequate surface quality. Laser powder bed fusion (LPBF), a digital additive manufacturing technology, presents a viable solution by facilitating the near-net shaping of hard-to-weld superalloys (HWSA). Although LPBF has made considerable progress, its widespread industrial application remains limited. To fully realize the potential of LPBF for producing high-integrity components, this review systematically examines the interplay between microstructural evolution, process parameters, post-treatment techniques, and shaping quality. It also categorizes crack types observed in LPBF-formed alloys and proposes mitigation strategies. Furthermore, the article outlines future research directions to address existing limitations and expand the applicability of LPBF in aerospace manufacturing.