The effect of fibers addition on the microstructure and mechanical properties of ZrO2 fibers toughened Al2O3/ZrO2 (Y2O3) solidified ceramics

• Published in: Materials today communications 2024-08, Vol.40, p.109817, Article 109817
• Main Authors: Chen, Zeye, Lan, Dehui, Gao, Rui, Cao, Weiwei, Liu, Xudong, Zhu, Luyi, Zheng, Yongting, Liu, Juncheng
• Format: Article
• Language: English
• Subjects: DSECs; Fibers toughening; Fracture toughness; Microstructure
• ISSN: 2352-4928; 2352-4928
• DOI: 10.1016/j.mtcomm.2024.109817

Fiber toughening is considered an effective way to strengthen the toughness of traditional sintered ceramics. Herein, ZrO2 fibers toughened Al2O3/ZrO2 (Y2O3) directionally solidified eutectic ceramics (DSECs) were prepared with the high-frequency induction heating zone melting (IHZM). The effects of ZrO2 fibers content on the phase composition, microstructure, and mechanical properties of the eutectic ceramics were studied. The findings revealed that DSEC consists of α-Al2O3 and ZrO2 phases, presents a typical colony microstructure. The phase spacing in the colony decreased with the addition of fibers, reaching a minimum value of 1.99 ± 0.25 μm at 20 wt%, which was nearly 40 % lower than that without the fiber’s addition. The hardness of DSEC increased gradually with the addition of fibers. Its highest value reaches 18.42 ± 0.55 GPa when the fiber content is 20 %. The fracture toughness of DSEC first increased and then decreased, reaching a maximum of 5.43 ± 0.22 MPa·m1/2 at 10 wt%, which was 1.5 times higher than that of the fibers-free eutectic ceramic. The improvement of fracture toughness was primarily due to the fibers toughening. In addition, the crack deflection, pinning, bridging, and branching had a significant inhibitory effect on the crack propagation. [Display omitted] •ZrO2 fiber toughened Al2O3/ZrO2(Y2O3) directionally solidified eutectic ceramic (DSEC).•The toughened DSEC phase spacing reduced to 1.99 μm, smaller 40 % than that without fiber.•Its fracture toughness reached 5.43 MPa·m1/2, 1.5 times that of DSEC without fiber.•The increase of fracture toughness is mainly attributed to the fiber toughening.