Di Egidio Gianluca, Martini Carla, Börjesson Johan, Ghassemali Ehsan, Ceschini Lorella, Morri Alessandro
Department of Industrial Engineering (DIN), Alma Mater Studiorum, University of Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy.
Department of Materials and Manufacturing, School of Engineering, Jönköping University, SE-551 11 Jönköping, Sweden.
Materials (Basel). 2023 Feb 28;16(5):2006. doi: 10.3390/ma16052006.
Few systematic studies on the correlation between alloy microstructure and mechanical failure of the AlSi10Mg alloy produced by laser-based powder bed fusion (L-PBF) are available in the literature. This work investigates the fracture mechanisms of the L-PBF AlSi10Mg alloy in as-built (AB) condition and after three different heat treatments (T5 (4 h at 160 °C), standard T6 (T6B) (1 h at 540 °C followed by 4 h at 160 °C), and rapid T6 (T6R) (10 min at 510 °C followed by 6 h at 160 °C)). In-situ tensile tests were conducted with scanning electron microscopy combined with electron backscattering diffraction. In all samples the crack nucleation was at defects. In AB and T5, the interconnected Si network fostered damage at low strain due to the formation of voids and the fragmentation of the Si phase. T6 heat treatment (T6B and T6R) formed a discrete globular Si morphology with less stress concentration, which delayed the void nucleation and growth in the Al matrix. The analysis empirically confirmed the higher ductility of the T6 microstructure than that of the AB and T5, highlighting the positive effects on the mechanical performance of the more homogeneous distribution of finer Si particles in T6R.
文献中很少有关于激光粉末床熔融（L-PBF）制备的AlSi10Mg合金微观结构与力学失效之间相关性的系统研究。本工作研究了L-PBF AlSi10Mg合金在铸态（AB）条件下以及三种不同热处理（T5（160℃保温4小时）、标准T6（T6B）（540℃保温1小时，随后160℃保温4小时）和快速T6（T6R）（510℃保温10分钟，随后160℃保温6小时））后的断裂机制。采用扫描电子显微镜结合电子背散射衍射进行原位拉伸试验。在所有样品中，裂纹形核均发生在缺陷处。在AB和T5状态下，相互连接的Si网络由于空洞的形成和Si相的破碎，在低应变时促进了损伤。T6热处理（T6B和T6R）形成了离散的球状Si形态，应力集中较小，这延迟了Al基体中空洞的形核和生长。分析经验性地证实了T6微观结构的延展性高于AB和T5状态，突出了T6R中更细小的Si颗粒更均匀分布对力学性能的积极影响。
