ABSTRACT

In the present work, monolithic liquid phase sintered SiC (LPS-SiC) was made by hot pressing method with nano-SiC powder. The system of sintering addictives which affects a property of sintering as well as the influence depending on compositions of sintering addictives were investigated by measurement of density, besides, mechanical properties such as flexural strength, elastic modulus were investigated to make sure of the optimum condition which is about matrix of SiCf/SiC composites. Sintered density, flexural strength and elastic modulus of fabricated LPS-SiC increased with increasing the sintering temperature. Also, flexural strength and elastic modulus were 587.5MPa and 216.3GPa, respectively.

INTRODUCTION

Silicon carbide (SiC) materials have been extensively studied for high-temperature components in advanced energy system and gas turbines, because it has excellent high-temperature mechanical properties and elastic modulus, low coefficient of thermal expansion, high thermal conductivity and good oxidation, corrosion and wear resistance (Ohring, 1995; Park, Yoon, Lee, Lee, Katoh, Kohyama, 2003). However, the brittle characteristics of SiC such as low strain-to fracture still impose a severe limitation on practical applications of SiC materials. For these reasons, silicon carbide fiber-reinforced silicon carbide matrix composite (SiCf/SiC composite) is promising for various structural materials, because of their good fracture toughness compared with monolithic ceramic materials. Especially, SiCf/SiC composite shows low activation on account of its low atomic number and good resistance to high-energy neutron irradiation and it is expected to be used as structural material in advanced energy systems such as fusion reactors (Snead, Jones, Kohyama and Fenici, 1996; Hasegawa, Kohyama, Jones, Snead, Riccardi and Fenici, 2000).

SiCf/SiC composite is mainly fabricated by chemical vapor infiltration (CVI), polymer impregnation and pyrolysis (PIP) and reaction sintering (RS) method (Kohyama, Seki, Abe, Muroga, Matsui, Jitsukawa and Matsuda, 2000; S. Sharafat, R. H. Jones, A. Kohyama, P. Fenici, 1995).

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