增材制造(AM)是一种逐层构建零件的技术。在过去的十年里,金属增材制造(AM)技术发展迅速,形成了完整的产业链。AM金属零件在众多行业中使用,包括生物医学,航空航天,汽车,海洋,和离岸。与现有制造工艺相比,可以在更大程度上改进部件的设计,这可以显著提高性能。已经报道了增材制造金属材料各向异性的研究,他们描述了使用增材制造工艺制备不同金属材料的优点和缺点;然而,在同一篇文章中,很少有深入而全面的研究总结不同类型增材制造金属材料的微观结构和力学性能。本文首先概述了增材制造过程之间的复杂关系,微观结构,和金属属性。然后解释了粉末床融合(PBF)和定向能量沉积(DED)的基本原理。接着描述了增材制造过程中的熔池和热影响区,并分析了它们对成形零件微观结构的影响。随后,增材制造钛合金的机械性能和典型的微观结构,不锈钢,镁铝合金,和高温合金,随着它们的各向异性,进行了总结和介绍。总结表明,导致金属AM零件机械性能各向异性的因素是其独特的微观结构特征或制造缺陷。该各向异性可以通过后热处理来改善。最后,介绍了金属AM各向异性的最新研究。
Additive manufacturing (AM) is a technology that builds parts layer by layer. Over the past decade, metal additive manufacturing (AM) technology has developed rapidly to form a complete industry chain. AM metal parts are employed in a multitude of industries, including biomedical, aerospace, automotive, marine, and offshore. The design of components can be improved to a greater extent than is possible with existing manufacturing processes, which can result in a significant enhancement of performance. Studies on the
anisotropy of additively manufactured metallic materials have been reported, and they describe the advantages and disadvantages of preparing different metallic materials using additive manufacturing processes; however, there are few in-depth and comprehensive studies that summarize the microstructural and mechanical properties of different types of additively manufactured metallic materials in the same article. This paper begins by outlining the intricate relationship between the additive manufacturing process, microstructure, and metal properties. It then explains the fundamental principles of powder bed fusion (PBF) and directed energy deposition (DED). It goes on to describe the molten pool and heat-affected zone in the additive manufacturing process and analyzes their effects on the microstructure of the formed parts. Subsequently, the mechanical properties and typical microstructures of additively manufactured titanium alloys, stainless steel, magnesium-aluminum alloys, and high-temperature alloys, along with their
anisotropy, are summarized and presented. The summary indicates that the factors leading to the
anisotropy of the mechanical properties of metallic AM parts are either their unique microstructural features or manufacturing defects. This
anisotropy can be improved by post-heat treatment. Finally, the most recent research on the subject of metal AM
anisotropy is presented.