Conventional sintering of LAS–SiC nanocomposites with very low thermal expansion coefficient

Abstract

Very low thermal expansion materials have been developed in a wide temperature range from -150 ºC to 450 ºC. These very low expansion materials are composed of a lithium aluminosilicate matrix with dispersed silicon carbide nanoparticles. The nSiC content in the most stable composite was 27 vol.%. Powder processing and sintering temperature control have been found to be of key importance in order to obtain low porosity sintered nanocomposites. Here, sintering by pressureless methods (conventional sintering) is proposed in order to obtain a LAS-nSiC nanocomposite with improved mechanical properties and excellent expansion behaviour by means of control of the phase reactions and glass formation during sintering