In Additive Manufacturing (AM), parts are normally fabricated along the direction perpendicular to the build plate. However, the main axis of the part may differ from this direction, leading to the concept of “build orientation” that is an essential aspect in Design for AM (DfAM). Build orientation defines the required support structures, that in turn affects build time, material waste, and part’s surface and mechanical properties. The present paper reviews the literature, focusing on the most utilized Powder Bed Fusion (PBF) techniques in metal AM. The findings are categorized based on properties affected by build orientation. First, manufacturability, geometrical accuracy, surface roughness, and porosity are reviewed. Then microstructural analysis, mechanical properties such as hardness, tensile strength, fatigue strength and fracture toughness are explored, followed by wear and corrosion properties. Consistent attention is given to studies describing the effects of build orientation on efficiency and applicability of post-processing techniques. Critical discussion of results highlights build orientation as a major factor to be considered in design and evaluation of PBF. In addition, prospects for the field are outlined, including the necessity of creating DfAM guidelines regarding build orientation, for which the current work is intended to serve as a starting point.

中文翻译：

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构建方向和倾斜特征对粉末床熔融增材制造金属零件的物理、微观结构和机械性能的影响


在增材制造 (AM) 中，零件通常沿着垂直于构建板的方向制造。然而，零件的主轴线可能与此方向不同，从而产生了“构建方向”的概念，这是增材制造设计 (DfAM) 中的一个重要方面。构建方向定义了所需的支撑结构，进而影响构建时间、材料浪费以及零件的​​表面和机械性能。本文回顾了文献，重点关注金属增材制造中最常用的粉末床熔融 (PBF) 技术。研究结果根据受构建方向影响的属性进行分类。首先，审查可制造性、几何精度、表面粗糙度和孔隙率。然后进行微观结构分析、硬度、拉伸强度、疲劳强度和断裂韧性等机械性能，然后是磨损和腐蚀性能。人们一直关注描述构建方向对后处理技术的效率和适用性的影响的研究。对结果的批判性讨论强调构建方向是 PBF 设计和评估中需要考虑的主要因素。此外，还概述了该领域的前景，包括制定有关构建方向的 DfAM 指南的必要性，当前的工作旨在作为起点。