Assessment of tests for use in process and quality control systems for selective laser sintering of polyamide powders

The aim of this study was to identify the optimum set of tests required for quality assurance purposes when selectively laser sintering polyamide powders. Both Nylon 11 and Nylon 12 powders are considered, and the tensile, flexural and impact properties are assessed, together with dimensional accuracy, density and melt flow index (MFI). It is concluded that MFI and strength are key measures, with impact strength the preferred strength measure because of its practicality. The MFI and strength measures may be augmented by assessment of dimensional accuracy and density for particular applications. Additional testing beyond these measures did not provide further significant information with regard to the mechanical integrity or dimensional accuracy of the output from a build.