| Abstract: | The purpose of this research is to investigate the effects of the volume fraction of tungsten carbide (WC) and laser power on the processing, structure, properties, and mechanical performance of WC-reinforced SS 316L composite materials, additively manufactured via Selective Laser Melting (SLM) - the primary objectives are to improve its wear resistance and bending performance. Steel matrix composites (SMC) have broad applications in various industries, especially in those which require of wear resistance and fatigue life. Additive manufacturing allows for the design and manufacturing of SMCs with tailored configurations. SMCs utilizing carbides such as TiC, Al²́²O²́³ and HA as reinforcements have been successfully manufactured but not fully understood. Along these lines, WC is chosen as a potential SMC reinforcement material due to its corrosion/high-temperature resistance and desirable mechanical properties such as high hardness (aiding abrasive wear resistance) and high toughness (aiding bending performance), among others. For this, a design of experiments is created to investigate the influence of laser power and WC Volume Fraction on the resulting macro- and micro-structures and mechanical performance of SMCs additively manufactured via SLM. Samples to be investigated were manufactured under several different volumetric energy density (VED) values by varying laser power and at different WC volume fractions. The use of microscopy and spectroscopy as well as three-point bend testing was used to study material microstructure and mechanical performance. Results show a significant improvement in hardness, elastic modulus, flexural modulus, and wear resistance with increasing WC volume content, while varying laser power had little influence. Manufacturing defects increased with increasing WC volume content, and specific laser power and WC volume content combinations were observed were observed to affect part quality. Altogether, this study enabled a better understanding of the additive manufacturing of WC-reinforced SS 316L composites by providing insight into the manufacturability and the resulting properties/performance of the samples. The electronic version of this dissertation is accessible from https://hdl.handle.net/1969.1/197808 |
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