Defining the tensile properties of Al-12Si parts produced by selective laser melting

Al-12Si samples were fabricated by selective laser melting. Different processing parameters, including four different hatch styles, as well as contour and base plate heating, were employed to evaluate their impact on the room temperature tensile properties. The samples with different hatch styles show similar crystallite sizes and lattice parameters of Al and comparable amount of free residual Si, but different levels of texture. The yield strength (YS) varies between 235 MPa and 290 MPa, the ultimate tensile strength (UTS) between 385 MPa and 460 MPa and the tensile ductility ranges between 2.8% and 4.5%. Similarly, the samples produced with and without contour show differences in their tensile properties. Base plate heating was employed with three different temperatures and the samples display improved plasticity with increasing base plate temperature (BP 473 K, 573 K and 673 K samples show a ductility of 3.5%, ∼3% and 9.5%, respectively). The results indicate that the room temperature tensile properties can be tuned (between YS: 115 MPa-290 MPa, UTS: 220 MPa-460 MPa and ductility: 2.8%-9.5%) in-situ during the selective laser melting process giving an opportunity to define the mechanical properties of the SLM parts to suit their service requirements.

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