Effect of temperature on tensile and fatigue properties of AlSi10Mg lattice structures fabricated by additive manufacturing

This study investigated the effect of temperature on tensile and fatigue properties of AlSi10Mg lattice structures fabricated by the laser powder bed fusion. Static tensile tests of lattice specimens were performed at -60 °C, room temperature (RT) and 200 °C, and fatigue tests using the lattice and cylindrical specimens were performed at RT and 200 °C. In the static tensile tests of the lattice specimens, decreasing temperature from RT to -60 °C resulted in a higher strength and an equivalent ductility whereas increasing temperature from RT to 200 °C resulted in a lower strength and a higher ductility. In the fatigue tests of the lattice specimens at RT, macroscopically, the elastic deformation was dominant under all load conditions, and Basquin’s law was able to be successfully applied. The fatigue life of the lattice specimens was less than one-tenth of that of the cylindrical specimens, which was attributed to stress concentrations in the lattice structures due to their geometries. In the fatigue tests at 200 °C, the fatigue behavior under low stress conditions of σ a ≤ 40.9 MPa was considered the high cycle fatigue, whereas the fatigue behavior under the highest stress conditions of σ a = 50.8 MPa was considered the low cycle fatigue. In the high cycle fatigue regime, the fatigue life at 200 °C was longer than that at RT, which may be unique to the lattice structure employed in this study.