On April 24, 2024, Zhang Ge's team from the Changchun Institute of Optics, Precision Mechanics and Physics of the Chinese Academy of Sciences published a paper entitled "Vat photopolymerization of large aperture high performance SiC mirror through multi-phase carbon injection modification" on the journal Additive Manufacturing (IF11.0). This research successfully improved the performance of SiC mirrors by improving the synthesis method of SiC materials, and successfully prepared the world's leading large-diameter additive manufacturing SiC mirrors. The core product of Changguang Chenying, the P300 laser confocal Raman spectrometer, is fortunate to provide a powerful tool for detecting the difference in crystal carbon content during the synthesis process of SiC materials in this study.

Abstract

Vat photopolymerization technique (VPP) shows advantages in rapidly preparation of complex structure silicon carbide matrix composites (Si/SiC). However, compared with traditional preparation technology, the properties of Si/SiC prepared via VPP are insufficient due to the presence of residual Si and carbon. Herein, the reaction mechanism of Si and carbon were systematically studied. Multiphase carbon was introduced into porous SiC preform via carbon precursor infiltration pyrolysis (CPIP) and graphitization methods. The content of residual Si was significantly decreased after reactive melt infiltration (RMI), and the residual carbon was eliminated through partial graphitization of the carbon. The influence mechanism of the carbon content and crystallinity on the reaction process of Si and carbon was studied. It suggested that the diameter of capillary channel and crystallinity of carbon are the main factors affecting residual carbon content in the final body after RMI. The sample with multiphase carbon achieved the best performance after RMI. The residual Si content, bulk density, flexural strength and elastic modulus are 11.58%, 3.04?g/cm3, 280.09?MPa and 355.48?GPa. In addition, the lowest coefficient of linear expansion was 2.39×10?6 K?1. Finally, a large-aperture SiC mirror with a diameter of 500?mm was prepared. Therefore, this research lays a foundation for promoting the application of large-aperture Si/SiC prepared via 3D printing.

The paper links：

https://www.sciencedirect.com/science/article/abs/pii/S2214860424002069