| Title |
Study on the Fabrication and Sintering Behavior of Silicon Nitride Ceramics for DLP-Based Ceramic 3D Printing |
| Authors |
이민호(Min-ho Lee); 안종필(Jong-pil Ahn); 소성민(Sung Min So); 이재승(Jae-seung Lee); 김진우(Jin-woo Kim); 김택윤(Tack-yoon Kim); 박주석(Joo-seok Park); 이희수(Heesoo Lee) |
| DOI |
https://doi.org/10.3365/KJMM.2025.63.7.507 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Ceramic 3D printing; Silicon nitride; DLP printing; Sintering behavior; Mechanical properties; GPS(Gas Pressure Sintering) |
| Abstract |
This study investigated the effects of sintering additives and sintering methods on the densification and mechanical properties of silicon nitride (Si3N4)-based ceramics for Digital Light Processing (DLP) 3D printing. The formation of dense sintered bodies was evaluated using both pressureless sintering and gas pressure sintering (GPS). X-ray diffraction (XRD) analysis confirmed that with increasing temperature α-Si3N4 transformed into β-Si3N4, and full transformation was achieved at 1800 ℃. Sintered density analysis showed that over 98% relative density was obtained at 1750 ℃, and GPS at 1900 ℃ yielded a maximum density above 99%. SEM observation further confirmed the formation of columnar β-Si3N4 grains and dense microstructures. Mechanical testing revealed that both flexural strength and Vickers hardness increased with additive content and sintering temperature, reaching maximum values of 1083 MPa and 1521 HV, respectively, under GPS at 1900 ℃. However, fracture toughness decreased due to grain coarsening under high-temperature GPS. Based on these findings, an optimized composition was selected for DLP printing. The specimen that was sintered using GPS at 1800 ℃ exhibited complete β-phase transformation, 97.9% relative density, 1072 MPa flexural strength, 1669 HV hardness, and 7.3 MPa·m1/2 fracture toughness, demonstrating its applicability for the fabrication of high-performance, complex-shaped Si3N4 spinal implant components.(Received 25 April, 2025; Accepted 19 May, 2025) |