The preparation and mechanical properties of carbon-carbon/lithium-aluminum-silicate composite joints

Silica carbide modified carbon cloth laminated C-C composites have been successfully joined to lithium-aluminum-silicate (LAS) glass-ceramics using magnesium-aluminum-silicate (MAS) glass-ceramics as interlayer by vacuum hot-press technique. The microstructure, mechanical properties and fracture mechanism of C-C/LAS composite joints were investigated. SiC coating modified the wettability between C-C composites and LAS glass-ceramics. Three continuous and homogenous interfaces (i.e. C-C/SiC, SiC/MAS and MAS/LAS) were formed by element interdiffusions and chemical reactions, which lead to a smooth transition from C-C composites to LAS glass-ceramics. The C-C/LAS joints have superior flexural property with a quasi-ductile behavior. The average flexural strength of C-C/LAS joints can be up to 140.26 MPa and 160.02 MPa at 25 degrees C and 800 degrees C, respectively. The average shear strength of C-C/LAS joints achieves 21.01 MPa and the joints are apt to fracture along the SiC/MAS interface. The high retention of mechanical properties at 800 degrees C makes the joints to be potentially used in a broad temperature range as structural components. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.