Abstract
The present investigation aims to assess the effect of direct aging (DA) on the metallurgical and mechanical behavior of an AlSi10Mg alloy processed through casting and selective laser melting (SLM). From the manufactured samples, one-half of the samples were kept as-fabricated and second half of the samples were subjected to direct aging at a temperature of 180 degrees C for 6 h. A dendritic structure with an alpha-Al phase surrounded by a eutectic Si phase is observed in the cast sample whereas a cellular structure bounded by a fibrous eutectic Si phase is observed in the SLM sample. The differences in the microstructural characteristics of the cast and built AlSi10Mg were attributed to the different cooling rates of the casting and SLM processes. The hardness of the DA-built AlSi10Mg sample was higher (1.32 GPa) than those of the as-built and cast samples. Similarly, the average yield strength and ultimate compressive strength of the DA-built sample were the highest (276 and 684 MPa, respectively) followed by those of the as-built, and as-cast samples. These results were attributed to the formation of a cellular microstructure with the nano-Si eutectic phase in the SLM process followed by DA. Furthermore, cost-effective components with superior mechanical properties can be fabricated through the SLM process using recycled AlSi10Mg powders.
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