Effect of Si Addition on Microstructure and Mechanical Properties of SiC Ceramic Fabricated by Direct LPBF with CVI Technology

In this paper, SiC and Si/SiC ceramics were fabricated using direct laser powder bed fusion with chemical vapor infiltration. Their microstructure, mechanical properties and the impacts of silicon addition were analyzed. The incorporation of silicon led to an increase in the relative density of the...

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Bibliographic Details
Main Authors: Yipu Wang, Pei Wang, Liqun Li, Jian Zhang, Yulei Zhang, Jin Peng, Xingxing Wang, Nan Kang, Mohamed El Mansori, Konda Gokuldoss Prashanth
Format: Article
Language:English
Published: MDPI AG 2025-08-01
Series:Applied Sciences
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Online Access:https://www.mdpi.com/2076-3417/15/15/8585
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Summary:In this paper, SiC and Si/SiC ceramics were fabricated using direct laser powder bed fusion with chemical vapor infiltration. Their microstructure, mechanical properties and the impacts of silicon addition were analyzed. The incorporation of silicon led to an increase in the relative density of the silicon carbide ceramics from 76.4% to 78.3% and the compression strength increased from 39 ± 13 MPa to 90 ± 8 MPa after laser powder bed fusion with chemical vapor infiltration. The melting and re-solidification of silicon allows the silicon to encapsulate the silicon carbide grains, changing the microstructure and the failure mechanism of the silicon carbide ceramics, resulting in a small amount of silicon residue. In the LPBF-CVI SiC ceramic specimen, the LPBF-formed SiC exhibits a microhardness of 24.2 ± 1.0 GPa. In LPBF-CVI Si/SiC, the spherical dual-phase structure displays a moderately increased hardness (25.9 ± 4.4 GPa), and the CVI-formed SiC exhibits a hardness of 55.3 ± 9.3 GPa.
ISSN:2076-3417