Key Parameters in the Manufacture of SiC-Based Composite Materials by Reactive Melt Infiltration

Abstract

The manufacture of SiC-based composites is quite widespread, and currently different methods are employed to produce them. The most efficient method, taking into account the cost/performance ratio, is reactive melt infiltration. It consists in infiltrating liquid silicon into a porous preform that must contain carbon, so that SiC is produced during infiltration. In the present work, the synthesis of two SiC-based composite materials with very different applications and microstructures has been studied and optimized. In both cases, materials have been obtained with suitable properties for the selected applications. One of the materials studied is silicon carbide particles/silicon (SiCp/Si) for protection systems such as armor jackets, and the other one is carbon fiber/silicon carbide (Cf/SiC) for use in braking systems. For the optimization, the dwell time and the atmosphere (Ar or primary vacuum) were used as variables. It has been found that in both preforms, the optimum conditions are 1 h dwell time and a vacuum atmosphere at 1450 °C. The effect of these parameters on microstructure and infiltration kinetics are discussed.

High-temperature Mechanical Properties and Their Influence Mechanisms of ZrC-Modified C-SiC Ceramic Matrix Composites up to 1600 °C

“…The silicon melt with a low viscosity climbed into the pores of ZrC-modified C/C preforms by capillary force, and simultaneously the SiC-based matrix was formed by in-situ reaction of liquid Si with adjacent carbonaceous materials. A similar process for the formation of SiC can also be found in the literature [21][22][23]. Following this procedure, the ZrC-modified C-SiC composites were fabricated.…”

“…If the fiber-matrix bonding is strong, the cracks can't effectively deflect along the fiber-matrix interface. However, for the weak fiber-matrix bonding interfaces, with the assistance of shear stress, the cracks could easily deflect along the fiber-matrix interfaces [21]. Figure 7 shows the morphologies of composites after flexural test at RT.…”

Interfacial Phenomena between Liquid Si-rich Si-Zr Alloys and Glassy Carbon

“…To design and produce such composites with tailored properties, the reaction bonded/formed silicon carbide process, belonging to spontaneous/pressure-less infiltration mechanisms, has well-known benefits over other conventional and costly sintering techniques, namely lower processing parameters (i.e., temperature, pressure, and time) and nearly-net shape fabrication capabilities [13][14][15][16][17]. In fact, SiC/ZrSi 2 composites have already been successfully produced by the reactive infiltration of three different liquid Si-rich Si-Zr alloys into bi-modal SiC preforms [18].…”

“…In parallel, the wetting characteristics and reactivity at the alloy/preform interfaces ought to be evaluated [27][28][29][30][31][32]. The as-collected knowledge can be profitably used as input data for optimizing the infiltration process [16,33].…”

Analysis of Nonlinear Transient Energy Effect on Thermoelectric Energy Storage Structure

“…The composite PCMs with high thermal conductivity and high latent heat were prepared by the melt infiltration method [27]. The porous matrix material with high melting point was used as the skeleton, and the phase change material with low melting point was melted into the porous matrix.…”