Correlation of Process Parameters and Surface Roughness in Laser Sintering Rapid Prototyping Technique

Abstract

AlSi10Mg is one of the most promising alloys in SLM technology due to its low weight and competitive mechanical properties. It gives a good alternative to the conventional manufacturing systems in terms of design flexibility, cost and production time. But the parts made from laser sintering of powder are bound to have rough surface texture. The present study is focused on investigating the impact of process parameters namely laser power, scan speed, hatch spacing and orientation on density and surface roughness of the specimens. newlineAlSi10Mg was sintered using selective laser melting. To characterize the parameters, design of experiments was created using the Box Behnken Design approach of Response Surface Methodology (RSM) while ANOVA analysis was employed to find the factors affecting the responses. The optimization was carried out in MATLAB using optimization toolbox. According to the study, hatch spacing was the most influential factor in influencing both density and surface roughness. The post processing was conducted using chemical polishing method. Chemical polishing has the advantage over other methods in that it can cover all contours without the use of additional tooling. Secondly, human intervention in chemical polishing is negligible. Thus, in the present study, the feasibility of chemical polishing to improve the surface quality of AlSi10Mg fabricated on SLM is explored. The results showed a positive response and the method proved to be economical and reliable. The chemical treatment of the surface of AlSi10Mg made by SLM proved to be effective to improve the surface finish. Initial surface roughness of the sample was 15 microns and the surface roughness after the chemical treatment was found to be 4 microns. There is no chemical change found in the part after the chemical treatment. newline