Achieving low surface roughness AlSi10Mg_200C parts using direct metal laser sintering

Laser sintered aluminum alloys produced by metal 3D printers can replace cast aluminum alloys in aerospace, defense, and marine industries by offering better mechanical properties, less porosity, and competitive fatigue characteristics. One of the major issues currently is the considerable surface roughness of additively manufactured aluminum alloys demanding post-processing procedures such as bead blasting or machining. In the current study, the process parameters such as laser power, scan speed, and hatch spacing were altered such that better surface roughness could be achieved for AlSi10Mg_200C using a Direct Metal Laser Sintering (DMLS) system. The process parameters were chosen such that three samples with the same core properties but different upskin characteristics were produced. The achieved surface roughness of the additively manufactured aluminum samples were almost as low as one fifth of the regular samples manufactured using standard process parameters. The microstructure and the porosity level of the samples printed by different process parameters were studied to reveal the causality of the low surface roughness for the proposed process. (C) 2017 Elsevier B.V. All rights reserved.