THE AlSi9Cu3 ALLOY PROCESSED BY THE SELECTIVE LASER MELTING TECHNOLOGY

The AlSi9Cu3 alloy, conventionally produced by High-Pressure Die Casting (HPDC), is extensively used in the automotive industry for its high specific strength, good heat and electric conductivity. There is currently an effort to produce this alloy using selective laser melting technology (SLM) due to design possibilities such as producing geometrically complex and lightweight products. However, the performance of SLM parts is highly dependent on its process parameters. The main aim of this research is to optimize the SLM process parameters of the AlSi9Cu3 alloy to achieve high mechanical performance. The tested process parameters were laser speed and hatch distance in the range of 1200-1500 mm.s(-1) and 120-170 mu m, respectively. The process parameters selection was performed based on a low porosity level. According to our study, the suitable combination of process parameters is laser power of 350 W, layer thickness of 50 mu m, scanning speed of 1400 mm.s(-1) and hatch distance of 120 mu m. Mechanical properties of SLM samples were compared with cast alloy according to the European Standard (EN 1706:2010). In this paper, the AlSi9Cu3 alloy produced by the SLM process outperformed the mechanical performance of the conventionally cast alloy in 0.2% proof stress (271 +/- 1.7 MPa compared to 160 MPa), ultimate tensile strength (494 +/- 2.6 MPa compared to 220 MPa), and elongation at break (5.6 +/- 0.2 % compared to 1.5 %).