Ablation resistance of HfC(Si, O)-HfB2(Si, O) composites fabricated by one-step reactive spark plasma sintering. Issue 4 (April 2021)

• Record Type: Journal Article
• Authors: Hao, Wei; Ni, Na; Liu, Tianyu; Zhou, Lei; Yao, Yao; Li, Ling; Jiang, Juan; Shi, Yinchun; Zhao, Xiaofeng; Xiao, Ping
• Is Part Of: Journal of the European Ceramic Society. Volume 41:Issue 4(2021)
• Page Start: 2226
• Page End: 2238
• Publication Date: 2021-04
• Subjects: Hafnium carbide -- Hafnium diboride -- Solid solutions -- Ablation resistance -- Solid-solution HfO2; 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.2020.11.054
• Languages: English
• ISSNs: 0955-2219

Abstract

Highlights: Dense HfC(Si, O)-HfB2 (Si, O) composites are fabricated to enhance ablation resistance of HfC. The composite is composed of HfC(Si, O), HfB2 (Si, O), O-doped SiC, and free carbon. The dense oxide layer contains Si-doped and (Si, B)-codoped HfO2, and HfB2 matrix grains. The HS15 composite sample exhibits a better ablation resistance. Abstract: A dense HfC(Si, O)-HfB2 (Si, O) composite was fabricated by reactive spark plasma sintering using HfC and SiB6 as starting reactants. The best ablation resistance was obtained with the composite fabricated with the addition of 15 vol.% SiB6 . After ablation under an oxyacetylene flame for 60 s, the mass and linear ablation rates of this composite were −0.007 mg cm −2 s −1 and −0.233 μm s −1, respectively. The negative ablation rates are the result of a slight mass gain/thickness increase, which indicate that the oxidation process was stable and mechanical scouring was limited during ablation. This enhanced ablation resistance was attributed to a unique double-layered oxide formation, which possessed lower oxygen permeability and better mechanical strength. The solid solution nature of the composite and its appropriate phase composition were responsible for the stable oxide structure formation.