Influence of Surface Milling in Mechanical Property of PA12 Parts Built by Laser Sintering

Laser sintering is one of the additive manufacturing technologies that used in product manufacturing. The mechanical property of the parts built by laser sintering is known to have anisotropy and design and building layout are limited by anisotropy. Stacking marks on surface is assumed in one of reason in anisotropy and it is expected that anisotropy is slacked off by removing stacking marks. In this study, difference of mechanical properties and anisotropy by whether post processed or not was investigated and to reveal effect of post processing was attempted. As post processed, specimen was cut out from laser sintering plate parts and was removed stacking marks. Tensile test was carried out and tensile properties and degree of anisotropy in post processed specimen and non-post processed specimen were compered. As a result, post processed specimen showed higher tensile strength and elongation at break than non-post processed specimen in build direction and anisotropy was became weaker in all tensile mechanical properties. This fact was suggested that post process by surface cutting is effective for making parts which have homogeneous mechanical properties.