Factorial design, processing, characterization and microstructure analysis of PIP-based C/SiC composites

Polymer impregnation and pyrolysis (PIP) process-based C/SiC composites are fabricated using the in-house synthesized methyl-polycarbosilane (PCS). Two-level factorial design matrix is employed to carry out experiments to study the effect of four factors on flexural strength of the composite. Total sixteen sets of composite samples are fabricated. Response table, normal probability plot, ANOVA and regression analysis are carried out to determine the statistical significant factors. Composite density (ρ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\rho $$\end{document}), fibre volume fraction (Vf\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$V_{\mathrm{f}}$$\end{document}) and pyrolysis temperature (T) are found to be statistically significant, while softening point (SP) of the PCS and interaction of these four factors are found insignificant. Higher levels of the density and Vf\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$V_{\mathrm{f} }$$\end{document} have shown positive effect, while the pyrolysis temperature has negative effect on the flexural strength of the composites. Flexural strength was found to be in the range of 374–592 MPa depending on the process parameters. The mechanical behaviour of the composites at different process conditions was explained with the help of their microstructures.