Enhanced Mechanical Properties of PUMA/SiO₂ Ceramic Composites via Digital Light Processing

This study aims to enhance the mechanical properties of additively manufactured polymer parts by incorporating ceramic particles (SiO₂) into diluted urethane methacrylate (UDMA) photopolymer resin using digital light processing (DLP) technology. The resulting PUMA/SiO₂ composites, featuring varying SiO₂ contents (16.7, 28.5, and 37.5 wt%) and processed under different conditions, underwent a comprehensive series of mechanical, thermal, and chemical tests. Hardness tests showed that composites with 37.5 wt% SiO₂ demonstrated superior hardness with low sensitivity to processing conditions. Bending tests indicated that elevated vat temperatures tended to degrade flexural properties, yet this degradation was mitigated in the case of the 37.5 wt% SiO₂ composition. Tensile tests revealed a transition from viscoelastic to linear elastic behaviors with increasing SiO₂ content, with high tensile strength sustained at low vat temperatures (<35 °C) when the SiO₂ content exceeded 28.5 wt%. Thermogravimetric analysis supported these findings, indicating that increased SiO₂ content ensured a more uniform dispersion, enhancing mechanical properties consequently. Thermal tests showed augmented thermal conductivity and diffusivity with reduced specific heat in SiO₂-inclusive composites. This study provides guidelines for optimal PUMA/SiO₂ composite utilization that emphasizes high SiO₂ content and low vat temperature, offering comprehensive insights for high-performance ceramic composite fabrication in functional applications.