Impact of post processing parameter on mechanical properties and surface roughness of selective laser sintered sand mold casting part

摘要

Rapid casting (RC) is an advanced manufacturing technology in additive manufacturing (AM) processes to produce casting parts rapidly. Selective laser sintering (SLS), that is used to produce sacrificial sand mould for casting metal parts in the foundry industry, is regarded as the RC. In this paper the impact of post curing time (PCT), post curing temperature (PCTP), coating (COAT) on the SLS sand mould to the assessment of surface roughness and mechanical properties of the final part produced have been examined. The Taguchi's L8 orthogonal array is selected for the experiments and findings are evaluated using analysis of variance (ANOVA). The experimental results show that the parameter PCTP has a significant effect on the mechanical properties and COAT on surface roughness. Surprisingly, the uncoated mould casting parts exhibit good surface finish than coated mould parts, due to the smaller diameter holes caused an uneven coating on the mould. The microstructure and bonding of the sintered moulds are observed by SEM analysis. Findings also suggest that machining will be always required to decrease the surface roughness.