EVALUATION OF HIGH-TEMPERATURE TENSILE PROPERTIES OF HEAT-TREATED ALSI10MG ALLOY PRODUCED BY LASER-BASED POWDER BED FUSION

The AlSi10Mg alloy is widely used to produce complex-shaped components by Laser-based Powder Bed Fusion (L-PBF); these parts, characterized by light structures and high specific strength, are currently employed in high-performance room temperature applications in the automotive and aerospace industries. However, it is important to increase the data concerning the high-temperature mechanical properties of the L-PBF AlSi10Mg alloy to spread its use. This study aims to fulfill the lack of knowledge by investigating the mechanical behavior at 200 °C, a representative condition of the average temperature of engine heads, of the L-PBF AlSi10Mg alloy subjected to a T5 heat treatment (artificial aging at 160 °C for 4 h) and an innovative T6 heat treatment (solubilization at 510 °C for 10 min and artificial aging at 160 °C for 6 h). The influence of high temperatures on the mechanical behavior of the L-PBF AlSi10Mg alloy was assessed by tensile tests, while microstructural and fractographic analyses were carried out to correlate the mechanical behavior of the alloy to its microstructure, and consequently explain the failure mechanisms. The ultrafine cellular microstructure, characterizing the T5 alloy, led to higher tensile strength than the homogeneous composite-like microstructure of the T6 alloy, which makes it very interesting for future application in the automotive and aerospace industries.