Flexural strength properties of MoSi<sub>2</sub> based composites

doi:2011.25.4.66

J. Ocean Eng. Technol. > Volume 25(4); 2011 > Article

J. Ocean Eng. Technol. 2011;25(4):66-71.
DOI: https://doi.org/10.5574/KSOE.2011.25.4.066

Flexural strength properties of MoSi₂ based composites

Lee Sang-Pill,Lee Hyun-Uk,Lee Jin-Kyung,Bae Dong-Su

Department of Mechanical Engineering Dong-Eui University,Department of Mechanical Engineering Dong-Eui University,Department of Mechanical Engineering Dong-Eui University,Department of Materials Science & Engineering Dong-Eui University

MoSi₂ 복합재료의 굽힘강도 특성

이상필,이현욱,이진경,배동수

동의대학교 기계공학과,동의대학교 기계공학과,동의대학교 기계공학과,동의대학교 신소재공학과

Keywords: Fabricating condition, Sintered density, Flexural strength, Microstructure

핵심용어: Nb sheet Nb 판재, 제조조건, 소결밀도, 굽힘강도, 미세구조

Abstract

The flexural strength of $MoSi_2$ based composites reinforced with Nb sheets has been investigated, based on the detailed examination of their microstructure and fractured surface. Both sintered density and porosity of Nb/$MoSi_2$ composites were also examined. Nb/$MoSi_2$ composites were fabricated by different conditions such as temperature, applied pressure and its holding time, using a hot-press device. The volume fraction of Nb sheet in this composite system was fixed as 10%. The characterization of Nb/$MoSi_2$ composites were investigated by means of optical microscopy, scanning electron microscope and three point bending test. Nb/$MoSi_2$ composites represented a dense morphology at the interfacial region, accompanying the creation of two types of reaction layer by the chemical reaction of Nb and $MoSi_2$. Nb/$MoSi_2$ composites possessed an excellent density at the fabricating temperature of $1350^{circ}C$, corresponded to about 95% of theoretical density. The flexural strength of Nb/$MoSi_2$ romposites were greatly affected by the pressure holding time at the same fabricating temperature, owing to the large suppression of porosity in the microstructure. Especially, Nb/$MoSi_2$ composites represented a good flexural strength of about 310 MPa at the fabricating condition of $1350^{circ}C$, 30MPa and 60min, accompanying the pseudo-ductile fracture behavior by the deformation of Nb sheet and the interfacial delamination.