Selective laser melting (SLM) is an important advanced additive manufacturing technology. The existing SLM products cannot fully meet the requirements of high-precision and strength of the mechanical component because of their defects. The TiAlN/TiN multilayer coating can improve the surface property of SLM products. The present work aims to explore the influences of different process parameters of SLM on the property of TiAlN/TiN multilayer coating plating on the 361L specimen and the mechanism of these influences. Taking laser power, scanning speed, and scanning space as factors, an orthogonal experiment was designed. The TiAlN/TiN multilayer coating specimens can be obtained by plating on the 361L specimen, fabricated by the process parameters of SLM on the orthogonal experiment. The surface topographies and properties of TiAlN/TiN multilayer coating were tested, the influences of SLM process parameters on TiAlN/TiN multilayer coating were analyzed, and the optimal process parameter was obtained. The electron microscope images revealed that the surface morphology of TiAlN/TiN multilayer coating plating on the SLM specimen was relatively flat, and there were some macro-particles in different sizes and pin holes dispersed on it. The thickness of the TiAlN/TiN multilayer coating was 2.77–3.29 μm. The microhardness value of coating SLM specimen was more than four times that of the uncoated SLM specimen and the wear rates of the uncoated specimen were 2–4 times that of the corresponding coating specimen. The comprehensive analysis shows that the laser power had the greatest influence on the comprehensive property of the coating. The primary cause of the influence of SLM process parameters on the properties of the TiAlN/TiN multilayer coating was preliminarily discussed. When the laser power was 170 W, the scanning speed was 1,100 mm/s, and the scanning space was 0.08mm, the TiAlN/TiN multilayer coating plating on the SLM specimen had the best comprehensive property.

Purpose Selective laser melting (SLM) is an important advanced additive manufacturing technology. The existing SLM printing technology cannot manufacture the mechanical parts that fully meet the requirements of high precision and strength. This paper aims to explore a new post-processing method for SLM 316L specimen, namely, using of the TiN/TiAlN multilayer coating fabricated by multi-arc ion plating on the surface of SLM specimens, for improving the performance of SLM specimens. The other purpose of this paper is compared the performances of the TiAlN/TiN multilayer coating machined specimen and the TiN/TiAlN multilayer coating SLM specimen. Design/methodology/approach The TiN/TiAlN multilayer coating is fabricated by multi-arc ion plating on the surface of 316L specimens. The surface morphology and selected mechanical properties of TiN/TiAlN multilayer coating plating on the SLM substrate specimen and the machined substrate specimen were studied in this paper. The analyzed properties included surface topography, micro hardness, the adhesion, the thickness and the wear resistance of TiN/TiAlN multilayer coating plating on the SLM substrate specimen and the machined substrate specimen. Findings The electron microscope images reveal that surface morphology of TiN/TiAlN multilayer coating plating on the SLM specimens is relatively flat, and there are some micro-particles in different sizes and pin holes dispersed on them. After TiN/TiAlN multilayer coating, the performances of SLM samples, such as micro hardness, the thickness and the wear resistance, were significantly improved. The micro hardness of TiN/TiAlN multilayer coating machined specimen is higher than that of TiN/TiAlN multilayer coating SLM specimen. However, the adhesion of TiN/TiAlN multilayer coating machined specimen is less than that of TiN/TiAlN multilayer coating SLM specimen. Originality/value The study provides a new post-processing method for SLM 316L specimen to improve the performance of SLM specimens and to enable SLM specimens to be applied in the field of precision mechanical transmission.