YUAN Qin;SONG Yong-Cai
Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, National University of Defense Technology;Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, National University of Defense Technology
The transformation from SiCO(Al) fiber to SiC(Al) fiber by high temperature heat-treatment was studied. The characteristics of SiC x O y decomposition and effects of different heating approaches on microstructure and densification processing of SiCO(Al) fibers were investigated. It was found that SiC x O y phase typically decomposed at temperature ranged from 1 430 °C to 1 850 °C. The SiC x O y phase in the core area of fiber could not be eliminated completely by continuous heat-treatment, even at the temperature as high as 1 800 °C. Furthermore, large pore faults and grain coarsening tended to be generated in the fibers due to over-high decomposition rate, which led to loose structure of fibers. By contrast, static heat-treatment could increase the degree of SiC x O y decomposition. The SiC x O y phase could be completely removed when the fibers were heat-treated at 1 650 °C for 1 h, and big pores and heterogenous grains were suppressed. Finally, densified SiC(Al) fibers with large β-SiC grains could be achieved after sintering at 1 900 °C.
SiCO(Al) fibers;SiC(Al) fibers;SiC x O y phase;β-SiC;densification
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