Selective laser melted (SLM) AlSi10Mg alloy was subjected to high cycle fatigue test to elucidate the effect of microstructural characteristics and sub-microscopic defects in its dynamic behaviour. The microstructure of the processed materials revealed scan tracks on the scanning surface and solidified melt pool/melt pool tracks on the surface in the build direction. The processed material exhibits equi-axed morphology with 100 fibre texture on the scanned surface and elongated grains preferably 100 orientation in the build direction. The pore size and distribution in the selective laser melted materials were measured using computed tomography method μ-(CT). The cellular structures constituting 500 nm sized grains were observed. The boundary of the cell was a eutectic mixture of Al and Si while the matrix comprised of primary α-Al as observed from TEM results. The influence of grain morphology, microtexture, pores, and cellular structure on the deformation behaviour of processed materials under cyclic loading were investigated. Load controlled axial fatigue test was conducted at a stress ratio of 0.1 and 25 Hz frequency. Fractographs revealed crack initiation occurred, typically, due to the pores and the Si particles in surface or sub-surfaces. The cellular structures in the microstructure played a significant role in influencing the fatigue crack path, depends on its location in the microstructure. Dislocations in the cellular matrix and dislocation fringes in the cellular boundaries observed through transmission electron microscopy affirms this influence. Anisotropy and shielding gases observed to exert no significant influences on the fatigue life of the processed material. The crack initiation and propagation are heavily influenced by surface/subsurface pores and cellular structure as evident from the detailed microscopic investigation made in the present work.

选择性激光熔融（SLM）AlSi10Mg合金经过高周疲劳测试，以阐明其微观结构特征和亚微观缺陷对其动态行为的影响。加工材料的微观结构显示了在扫描表面上的扫描轨迹以及在构建方向上表面上的固化熔池/熔池轨迹。加工后的材料表现出等轴形态，在扫描的表面上具有100根纤维织构，并且在构造方向上最好具有100个方向的细长晶粒。使用计算机断层扫描法μ-（CT）测量选择性激光熔融材料的孔径和分布。观察到构成500nm尺寸晶粒的孔结构。电池的边界是Al和Si的共晶混合物，而从TEM结果可以看出，基体由主要的α-Al组成。研究了颗粒形态，微观结构，孔洞和孔结构对循环载荷下加工材料变形行为的影响。在频率为0.1和25 Hz的应力比下进行负载控制的轴向疲劳测试。断裂仪显示出裂纹的发生通常是由于表面或亚表面的孔和硅颗粒所致。微观结构中的孔结构在影响疲劳裂纹路径方面起着重要作用，这取决于其在微观结构中的位置。通过透射电子显微镜观察到的细胞基质中的位错和细胞边界中的位错条纹证实了这种影响。观察到各向异性和保护气体不会对加工材料的疲劳寿命产生重大影响。裂纹的萌生和扩展受表面/亚表面孔隙和孔结构的严重影响，这从本工作的详细微观研究中可以明显看出。