Preparation and selective laser sintering of nylon-12 coated metal powders and post processing

A dissolution-precipitation process was successfully developed to prepare nylon-12 coated carbon steel powders. The SEM and laser diffraction particle size analysis results show that the metal particles are well coated by nylon-12 resin; therefore, an effective method for preparing nylon-12 coated metal powders is provided. Green parts were formed from the coated powders by selective laser sintering (SLS) process, and when the nylon-12 content in the coated powder was 1.0wt% and the applied laser energy density was 0.06J/mm(2), the SLS green parts had sufficient strengths for features as small as 0.1 mm to be built and post-processed, and relatively high dimensional accuracy. The SLS green parts were post-processed by binder decomposition and epoxy resin infiltration, and the obtained epoxy-infiltrated parts have the dimensional errors in the X, Y and Z directions of -0.30, -0.32 and -0.25% respectively, and the bend strength, bend modulus, tensile strength and impact strength of 93.4 MPa, 14.7 GPa, 70.3 MPa and 12.4 MPa respectively (C) 2009 Elsevier B.V. All rights reserved