Preparation and selective laser sintering of nylon coated metal powders for the indirect SLS process

摘要

Purpose The purpose of this paper is to report a new method, the dissolution-precipitation process, to prepare nylon coated metal powders for the indirect selective laser sintering (SLS) process.Design/methodology/approach The nylon-12 coated carbon steel powders were prepared by the dissolution-precipitation process. The microcosmic appearance of the coated powder was observed by scanning electron microscope (SEM). The effect of the applied laser energy density on the three-point bend strength and dimensional accuracy of the SLS specimens was studied. The influence of nylon-12 content on the bend strength of the SLS specimens was investigated.Findings The SEM micrograph of the coated powder shows that the steel particles are well coated by nylon-12 resin. The bend strength of the SLS specimens increases with increasing the applied energy density until it reaches a maximum value, and then further increasing energy density will cause the decrease in the bend strength.The bend strength of the SLS specimens increases with increasing the nylon-12 content. The dimensional errors in the X, Y and Z directions are all increased with the increase in energy density.Research limitations/implications This study only concerns the preparation and SLS of the coated powders.Further investigations are planned to be conducted on the post processes, such as binder decomposition and high temperature sintering, of the green parts made from the coated powders.Originality/value This study provides a useful method for preparing nylon coated metal powders for making metal parts by the indirect SLS process.