Ablation behavior and mechanism of bulk MoAlB ceramic at ∼1670–2550 °C in air plasma flame. Issue 11 (September 2021)

• Record Type: Journal Article
• Authors: Su, Xiaojia; Hu, Baotong; Quan, Yu; Qin, Yanru; Feng, Qingguo; Hu, Chunfeng
• Is Part Of: Journal of the European Ceramic Society. Volume 41:Issue 11(2021)
• Page Start: 5474
• Page End: 5483
• Publication Date: 2021-09
• Subjects: MoAlB -- Spark plasma sintering -- Plasma exposure -- Ablation behavior -- Ablation mechanism; 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.2021.04.039
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: In this work, MoAlB samples for plasma exposure test were condensed by spark plasma sintering at 1200 °C for 10 min. Ablation resistance of MoAlB ceramic was investigated in a plasma torch facility for about 30 s at high temperature range of ∼1670−2550 °C, which provided a quasi-real hypersonic service environment. The results showed that the linear ablation rate was increased from 0 μm/s at ∼1670 °C to 86.4 μm/s at ∼2550 °C. At ∼1670 °C, the ablated surface of MoAlB ceramic was covered by Al2 O3 layer, presenting excellent ablation resistance. At ∼2220 °C, the macroscopic cracks were induced by thermal stress, which opened up channels for the inward diffusion of oxygen and deteriorated the ablation resistance of the substrate. Above ∼2400 °C, the volatile MoO3 and B2 O3 and the erosion of viscous oxides by the high shearing force of plasma stream were the main ablation mechanisms.