Microstructures and mechanical properties of Ti3(Al, Si)C2/Al2O3 composites fabricated by current-assisted sintering of Ti3AlC2/SiO and Ti3AlC2/SiO2. Issue 5 (1st March 2023)

• Record Type: Journal Article
• Authors: Zhang, Zhenyu; Ji, Jun; Ma, Deli; Du, Yuhang; Wei, Yulin; Shi, Guopu; Wang, Zhi; Sun, Mengyong; Chen, Fei; Huang, Shifeng; Li, Qinggang
• Is Part Of: Ceramics international. Volume 49:Issue 5(2023)
• Page Start: 8533
• Page End: 8545
• Publication Date: 2023-03-01
• Subjects: Al2O3 -- Low-temperature densification -- Replacement reaction -- Ti3(Al, Si)C2; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.11.016
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Ti3 SiC2 /Al2 O3 composites attract attention because Ti3 SiC2 and Al2 O3 have complementary advantages in mechanical properties. However, the high temperatures (≥1400 °C) required for densification of the Al2 O3 lead to the decomposition of Ti3 SiC2 . To address this issue, Ti3 (Al1-x Six )C2 /Al2 O3 composites were fabricated via current-assisted sintering of Ti3 AlC2 /SiO (TM sample) and Ti3 AlC2 /SiO2 (TD sample) at 1100–1300 °C. After sintering, most Al atoms in Ti3 AlC2 were substituted by Si atoms, forming Ti3 (Al1-x Six )C2 with values of x greater than 0.85. However, the morphologies of Al2 O3 produced from Ti3 AlC2 /SiO and Ti3 AlC2 /SiO2 were different. Spherical Al2 O3 produced by Al–Si substitution in SiO2 was difficult to densify at low temperatures, whereas the reaction between Ti3 AlC2 and SiO disintegrated the matrix of SiO and produced dense Al2 O3 . As a result, the relative densities and mechanical properties of TM samples were less affected by a reduction in sintering temperature than those of TD samples. As sintering temperature declined from 1300 °C to 1100 °C, flexural strength, hardness, and fracture toughness of TM samples decreased by 35.9% (from 546.2 MPa to 350.0 MPa), 27.4% (from 4.56 GPa to 3.31 GPa), and 33.4% (from 7.45 MPa m 0.5 –4.96 MPa m 0.5 ), respectively. Meanwhile, the flexural strength, hardness, and fracture toughness of TD samples were reduced by 81.2% (from 466.1 MPa to 87.6 MPa), 85.4% (from 6.50 GPa to 0.95 GPa), and 68.6% (from 6.94 MPa m 0.5 –2.18 MPa m 0.5 ), respectively. Therefore, Ti3 AlC2 /SiO is more suitable for fabricating Ti3 (Al1-x Six )C2 /Al2 O3 composites at low temperatures.