Mechanical properties and oxidation behavior of Ti-doped Nb4AlC3. Issue 4 (March 2016)

• Record Type: Journal Article
• Authors: Gu, Jian; Pan, Limei; Yang, Jian; Yu, Lei; Zhang, Haibin; Zou, Wenjie; Xu, Canhui; Hu, Chunfeng; Qiu, Tai
• Is Part Of: Journal of the European Ceramic Society. Volume 36:Issue 4(2016)
• Page Start: 1001
• Page End: 1008
• Publication Date: 2016-03
• Subjects: (Nb1 − xTix)4AlC3 solid solutions -- In situ synthesis -- Mechanical properties -- Oxidation resistance; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2015.10.023
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: Herein, we present the first report on fully dense and phase pure (Nb1 − x Ti x )4 AlC3 ceramics ( x = 0–0.3), fabricated by in situ reaction hot-pressing method. The solid solution of Ti provides a significant strengthening effect to Nb4 AlC3 . Typically, (Nb0.8 Ti0.2 )4 AlC3 exhibits the highest flexural strength (508 ± 28 MPa) and fracture toughness (8.4 ± 0.2 MPa m 1/2 ), increasing by 47% and 18%, respectively. The Vickers hardness of (Nb0.7 Ti0.3 )4 AlC3 (4.4 ± 0.2 GPa) is 69% higher than that of Nb4 AlC3 . The (Nb0.8 Ti0.2 )4 AlC3 also retains a high Young's modulus of 294 GPa at 1500 °C (84% of room-temperature value). Due to the formation of a more protective oxide scale consisting of TiNb2 O7 and NbAlO4, the (Nb1 − x Ti x )4 AlC3 exhibits a greatly improved oxidation resistance. Interestingly, a better oxidation resistance at 1000 °C and 1100 °C than at 800 °C and 900 °C was observed for (Nb1 − x Ti x )4 AlC3 . Excellent comprehensive properties render the (Nb1 − x Ti x )4 AlC3 solid solutions promising high-temperature structural materials.