Phase stability of SiC/SiC fiber reinforced composites: The effect of processing on the formation of α and β phases

• Published in: Materials letters Vol. 241; no. C; pp. 123 - 127
• Main Authors: Santoro, Uriel, Novitskaya, Ekaterina, Karandikar, Keyur, Khalifa, Hesham E., Graeve, Olivia A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.04.2019; Elsevier BV; Elsevier
• Subjects: Composite structures; Fiber composite; Fiber composites; Hot pressing; Materials processing; Materials science; Phase stability; Phase transitions; Plasma sintering; Pressing; Silicon carbide; Spark plasma sintering; Hot pressing; Spark plasma sintering; Phase stability; Silicon carbide; Materials processing; Fiber composite
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2019.01.055

[Display omitted] •β-SiC composites are sintered to full density using spark plasma sintering.•The conversion to α-SiC can be avoided using spark plasma sintering.•Hot-pressed composites convert to α-SiC because of long processing times. We describe the β → α phase transformation in SiC/SiC fiber-reinforced composites prepared by spark plasma sintering (SPS) and hot-pressing, resulting in samples of >96% relative density and uniform β-SiC microstructure for the SPS composites. Starting from β-SiC powders, the phase transformation from β to α in the samples manufactured by SPS is shown to be suppressed due to the influence of lower sintering temperature, shorter processing time, and higher pressure. These samples are compared to ones produced by a hot-pressing (HP) technique that results in samples with very significant conversion to α-SiC. This study is of special interest for the production of SiC/SiC composite structures for electronic, structural, and nuclear applications.