Abstract An original approach based on 2D fracture surface and 3D X-ray tomography analysis is proposed in this paper. Its application in selective laser melting of Ti-6Al-4V provides substantive clarifications regarding both mechanisms of porosity formation and their influence on mechanical properties. Unambiguously, a one-to-one relationship between the scanning strategy pattern and the 3D spatial distribution of porosities is highlighted. In an original manner, the 3D location of porosities, their morphology and their orientation are analyzed with respect to the laser spot path. The results show that pores are mainly localized on the overlay zones and support the lack of energy induced by the lower energy at the periphery of the laser spot as the main mechanism of porosity formation. Finally, both tensile properties and crack path are shown to be influenced by the presence and 3D distribution of porosities.

中文翻译：

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Ti-6Al-4V零件激光选区熔化孔隙形成机制及对力学性能的影响

摘要 本文提出了一种基于2D断裂面和3D X射线断层扫描分析的独创方法。它在 Ti-6Al-4V 的选择性激光熔化中的应用提供了关于孔隙形成机制及其对机械性能的影响的实质性澄清。明确地，突出显示了扫描策略模式与孔隙度的 3D 空间分布之间的一对一关系。以原始方式，相对于激光光斑路径分析孔隙的 3D 位置、它们的形态和方向。结果表明，孔隙主要位于覆盖区，支持激光光斑外围较低能量引起的能量缺乏是孔隙形成的主要机制。最后，