TEM Study on the Additive-Manufactured AlSi10Mg Article Swipe
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· 2020
· Open Access
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· DOI: https://doi.org/10.1017/s1431927620024241
· OA: W3046437198
Additive manufacturing is a low-cost solution for the flexible production of customized products in the automotive industry, especially for low volume production, without significantly increasing the lead time when compared to traditional manufacturing processes [1].Among various technologies of additive manufacturing for metals, Laser Powder Bed Fusion (LPBF) is one of the most promising ways for the fabrication of metallic components with complex structures while maintaining a high standard for performance [2].Aluminum alloys have been used extensively on vehicles for light-weighting and ultimately improving fuel efficiency.The additive manufacturing of aluminum alloys has been difficult because of their high reflectivity, high thermal conductivity, high susceptibility to oxidation, as well as poor flowability due to the low density of aluminum powders [3].The limited understanding of the correlation between process conditions and microstructure features of different length scales makes the fabrication even more challenging since the mechanical properties of the alloy are dominated by the microstructure features.Among them, process induced formation of various types of defects [4, 5] and ultrafine subgranular Si precipitates in Al-Si eutectics [6,7] have drawn extensive research interest in the recent years.A couple of typical defects are lack-of-fusion, which is aptly named, and keyhole, which is a deep and narrow vapor cavity in the shape of keyhole caused by the evaporation of elements [8].However, most previous studies focus on exploring the role of process parameters in the formation of either of these two microstructure features, while the intertwining between them is usually overlooked.In fact, altered process parameters could lead to a simultaneous change in the formation of both defects and subgranular microstructure, which should be comprehensively considered for process optimization and material modeling.To bridge this gap, we present the microstructural study by transmission electron microscopy (TEM) on one typical aluminum alloy, AlSi10Mg, built with different parameters to intentionally generate certain types of defects.
