While significant progress has been made in understanding laser powder bed fusion (L-PBF) as well as the fabrication of various materials using this technology, there is still limited adoption in the industry. One of the key obstacles identified is the lack of materials that can truly manufacture functional parts directly with L-PBF. This paper covers the emerging research on in-situ alloying and multi-metal processing. A comprehensive overview of the underlying scientific topics behind them is presented. The current state of research and progress from different perspectives (the materials and L-PBF processing parameters) are reviewed in order to provide a basis for follow-up research and development of these approaches. Defects, especially those associated with these two material processing routes, are also elucidated by discussing the mechanisms of their formation, including the main influencing factors, and the tendency for them to occur. Future research trends and potential topics are illustrated. The final part of this paper summarizes findings from this review and outlines the possibility of in-situ alloying and multi-metal processing using L-PBF.

尽管在理解激光粉末床熔合（L-PBF）以及使用该技术制造各种材料方面已经取得了重大进展，但是在行业中仍采用有限。确定的主要障碍之一是缺乏可以直接使用L-PBF真正制造功能部件的材料。本文涵盖了新兴的原位研究合金化和多金属加工。提供了对它们背后的基础科学主题的全面概述。综述了不同角度（材料和L-PBF加工参数）的研究现状和进展，以便为这些方法的后续研究和开发提供基础。通过讨论缺陷的形成机理，包括主要的影响因素，以及它们发生的趋势，也可以阐明缺陷，尤其是与这两种材料加工路线相关的缺陷。阐明了未来的研究趋势和潜在主题。本文的最后一部分总结了这次综述的发现，并概述了使用L-PBF进行原位合金化和多金属加工的可能性。