Mechanical properties and microstructure of 3D orthogonal quartz fiber reinforced silica composites fabricated by silicasol-infiltration-sintering

Sol-gel process and high-temperature property of SiO2/ZrO2-SiO2 composites

High-temperature properties of 2.5D SiO2f/SiO2 composites by sol–gel

The effect of two different fiber architectures on the mechanical properties of the quartz fiber-reinforced silica composites processed by silicasol-infiltration-sintering (SIS) has been investigated. The composites were sintered at relatively low temperature (450 °C). The characteristics of 2.5D (shallow bend-joint) structure and 3D orthogonal structure were determined. The microstructures, flexural strength, shear strength and failure mechanisms of both 2.5D (shallow bend-joint) and 3D orthogonal composites were characterized. It was found that the fiber placement in the preform will strongly affect the mechanical property and failure behavior of the composite. The results of the tests and microstructural observations indicated that 2.5D (shallow bend-joint) quartz f /silica (Q f /S) composites had better mechanical properties than 3D orthogonal quartz f /silica composites.

Mechanical behavior of 2.5D (shallow bend-joint) and 3D orthogonal quartzf/silica composites by silicasol-infiltration-sintering

Mechanical properties and microstructure of 2.5D (shallow straight-joint) quartz fibers-reinforced silica composites by silicasol-infiltration-sintering

In this paper, 2.5D SiO2f/SiO2 composites were fabricated via sol-gel process employing 2.5D braided silica fiber fabrics as reinforcements and high pure silicasol as slurry. The process parameters are optimized and the optimal parameters are as follows: the silicasol of 30.8 wt. % as slurry, microwave drying, and sintering at 900 °C. Utilizing the optimal process parameters, the density and the flexural strength of the composites can reach 1.65 g•cm-3 and 80.68 MPa respectively. Dielectric properties of the 2.5D SiO2f/SiO2 composites were also measured, and the real part of the permittivity is 3.40 at 5 GHz. The excellent mechanical and dielectric properties of the 2.5D SiO2f/SiO2 composites can well meet the requirements of radome materials.

Studies on Preparation and Property of 2.5D SiO2f/ SiO2 Composites

The effect of temperature and UV irradiation on the corrosion behavior of 304 stainless steel exposed to a simulated marine atmosphere was studied. The corroded samples were analyzed in detail through potentiodynamic polarization, in situ electrochemical impedance spectroscopy, Mott–Schottky measurements, scanning electron microscopy, and X‐ray photoelectron spectroscopy. The results showed that the corrosion rate of 304 SS was significantly inhibited by UV irradiation, and the inhibition effect increased at a higher temperature. The UV irradiation not only changed the corrosion products morphologies formed on the 304 SS surface but also the relative content of the corrosion products was changed. In particular, UV irradiation can promote the formation of Cr2O3 in corrosion products, especially at a higher temperature, thus improving the corrosion resistance of 304 SS.

Jun Wu Tang

Papers

Studies on Preparation and Property of 2.5D SiO2f/ SiO2 Composites

The effect of temperature and UV irradiation on corrosion behavior of 304 stainless steel exposed to a simulated marine atmosphere