Effects of Laser Scanning Speed on Sc‐Modified AlSi7Mg Alloy Fabricated by Selective Laser Melting: Microstructure and Nanomechanical Properties

Selective laser melting (SLM) was used to fabricate Sc‐modified AlSi7Mg alloy. This study investigated the effects of laser scanning speed on forming quality, microstructure, and nanomechanical properties of the new AlSi7Mg0.526Sc alloy. The experimental results indicated that as the scanning speed increased, the relative density and solid solution strengthening effect initially increased and then slightly decreased, while the surface roughness decreased, and the grain size first decreased and then increased. At a scanning speed of 1400 mm/s, the SLM‐ed AlSi7Mg0.526Sc sample demonstrated the highest relative density (98.99%), the relatively lowest surface roughness (Ra = 5.62 μm), the finest average grain size (4.82 μm), and the optimum nanohardness (2.04 GPa). These superior properties were attributed to the high forming quality, fine microstructure, and effective solid solution strengthening.