Validation of an experimental procedure to quantify the effects of powder flowability on selective laser sintering process

This paper proposes the characterization technique of powder quality for SLS application by using a set up that mimics the movements in an SLS apparatus. A roller is used to spread the powder in layer. The quality of the powder layer produced is characterized by means of an indentation test carried out with a dynamometer. In particular, the dynamometer allows to assess the degree of compaction of the layer, measuring the force required to penetrate the layer. Subsequently, the tests of mechanical strength carried out on the sintered specimen are used to correlate the characteristics of the powder bed to the final product properties. It is found that in the case in which the roller is able to increase the compaction of the bed also the strenght of the sintered material changes. The maximum of the compression effect on the strength of the sintered material (+41.5 %) is obtained for the smallest particle size tested, a powder 16 μm powder.