Stellite 6 alloy has excellent wear resistance, corrosion resistance, and oxidation resistance, however the difficulties in traditional processing limit its wide application. Additive manufacturing technology that has emerged in recent years is expected to provide a new way for the processing of stellite 6 alloy. In this study, two square thin-walled stellite 6 parts were fabricated through the wire arc additive manufacturing technology. At the same time, the effect of stress relief annealing on the mechanical performance of the fabricated stellite 6 part was studied and compared with the corresponding casting part. The results indicate that the additive manufacturing stellite 6 components exhibit satisfactory quality and appearance. Moreover, the microstructure of the additive manufacturing part is much finer than that of the casting part. From the substrate to the top region of the additive manufacturing part, the morphology of the dendrites changes from columnar to equiaxed, and the hardness increases firstly and then decreases gradually. In addition, the average hardness of the additive manufacturing part is ~7–8 HRC higher than the casting part. The ultimate tensile strength and yield strength is ~150MPa higher than the casting part, while the elongation is almost the same. The stress relief annealing has no significant effect on the hardness of the AM part, but it can slightly improve the strength.

Under extreme conditions in fields including aerospace exploration, deep earth excavation, and ocean engineering, mechanical components are subjected to severe environmental challenges, such as high temperature, heavy load, fatigue fracture and corrosion, which significantly limit their service life and operational reliability. Surface engineering has emerged as a critical strategy to address these problems by modifying surface characteristics while preserving basic properties of raw materials. Among various surface modification techniques, laser-based surface modification stands out due to its precise processing, high throughput, and outstanding surface performance. However, laser-based surface modification of metallic materials for industrial applications remains limited owing to inadequate systematic understanding regarding the fabrication mechanisms. Accordingly, a comprehensive and holistic review is essential to elucidate the effect of laser-based surface modification on process optimization, system development, microstructure evolution, and performance enhancement. This review systematically expounds two fundamental strategies in laser surface modification-based material modification (exemplified by laser cladding) and structural modification (exemplified by laser shock peening) in terms of mechanism, process, performance and application. In addition, the mechanism and potential of the synergistic integration of LC (laser cladding) and LSP (laser shock peening) are emphatically discussed. Finally, perspectives regarding process optimizations, material developments, and system improvements for laser surface engineering are presented. By establishing a clear “mechanism–process–performance–application” narrative, this review aims to provide both a scientific reference and a practical guideline for the severe demands of extreme operating conditions.