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

Abstract

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 powder characteristics are examined by scanning electron microscope (SEM) and laser diffraction particle size analysis. The effect of the applied laser energy density on the three‐point bend strength and dimensional accuracy of the SLS specimens are studied. The influence of nylon‐12 content on the bend strength are also investigated. Findings The SEM and laser diffraction particle size analysis results indicate 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 over the investigated range. The dimensional errors in the X ‐ Y ‐and Z ‐directions are all increased with the increase in energy density. Research limitations/implications This paper only concerns the preparation and SLS of the coated powders. Further investigations are planned into post‐processing, such as binder decomposition and high‐temperature sintering, of the green parts made from the coated powders. Originality/value This paper provides a useful method for preparing nylon‐coated metal powders for making metal parts by the indirect SLS process.