Synergistic Improvement of Thermal Conductivity, Tensile Performance and Hardness of DLP 3D Printed Composite using Boron Nitride and Aluminum Oxide Fillers

Zeeshan Hamid Malik , Ir. Muhammad Akhsin Muflikhun, S.T., MSME., Ph.D; Ir. Achmad Pratama Rifai, S.T., M.Eng., Ph.D and Associate Professor, Tan U-Xuan, Ph.D (SUTD Singapore)

2024 | Tesis | S2 Teknik Mesin

This study addressed the pressing need for advanced thermal management materials in modern electronic power systems. By synergistically incorporating low-content alumina and boron nitride fillers with polyurethane acrylate resin in DLP 3D printing, the research aimed to augment thermal conductivity, thermal stability, and mechanical properties in thermally conductive substrates.

Polymers inherently exhibit low thermal conductivity, limiting their effectiveness in thermal management. This study overcame this limitation by integrating highly thermally conductive fillers, creating pathways for efficient heat conduction within composite materials.

Various testing methods, including thermal conductivity measurements, thermal stability analysis, mechanical performance evaluation, hardness testing, surface roughness analysis, and chemical structure analysis, were employed to comprehensively assess the performance of the composite materials.

The findings and solutions presented in this study are valuable for addressing heat related challenges in diverse industries, including IT/IoT and electric vehicles, contributing to advancements in 3D printing of thermal management technologies.

This Master thesis investigated the enhancement of thermomechanical properties in DLP 3D-printed nanocomposites by synergistically incorporating low-content alumina and boron nitride fillers with polyurethane acrylate resin. The research explored the impact of nanofillers addition on thermal conductivity, thermal stability, mechanical properties, surface roughness, and chemical structure integrity. Various testing methods were executed, including thermal conductivity measurements by means of the FOX 50 Heat Flow Meter, thermal stability analysis via thermogravimetric analysis (TGA), mechanical performance evaluation using ASTM D638-IV tensile tests, hardness testing with the GS-709G Shore D Hardness Tester, surface roughness analysis with stylus profiler KLA Tencor D-600, and chemical structural analysis with Fourier-transform infrared spectroscopy (FTIR).

Findings highlighted that the addition of nanofillers improved thermal conductivity, with synergistic approach of filler loading exhibiting the most significant enhancements. Thermal stability was also enhanced, as evidenced by higher decomposition temperatures and lower degradation rates compared to pure resin. However, the study noted a trade-off with mechanical properties, where increased filler content reduced ductility and hardness. Surface roughness was found to influence thermal conductivity, highlighting the importance of optimizing surface characteristics for thermal performance. 

Sample code RAB 6 exhibited notable enhancements, including a 9% increase in thermal conductivity at 30°C, a high decomposition temperature of 490°C, a substantial residue weight of 14.6%, a roughness (Ra) of 2.01 microns, a surface hardness of 83.89, and maintained chemical structure integrity. However, it experienced a 25% reduction in strain at break compared to pure polyurethane acrylate resin.

Kata Kunci : 3D Printing, Polymer nanocomposite, Thermal conductivity, Thermal stability, Boron nitride, Aluminum oxide, Mechanical properties.