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Indexed by:期刊论文

Date of Publication:2013-11-01

Journal:INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS

Included Journals:SCIE、EI、Scopus

Volume:41

Page Number:489-494

ISSN No.:0263-4368

Key Words:Composites; Mechanical properties; Microstructure

Abstract:In the present work, the effects of the sintering temperature and time on the microstructure and mechanical properties of the MoSi2-SiCw composites were investigated in detail. The results indicated that the relative density of the MoSi2-SiCw composites increased first and then decreased as the sintering temperature increased from 1500 degrees C to 1750 degrees C, and the maximum relative density of 99.7% was obtained for the MoSi2-SiCw composite sintered at 1650 degrees C. As the sintering temperature increased from 1650 degrees C, the flexural strength of MoSi2-SiCw composites increased from 428 MPa to 646 MPa, and then the flexural strength did not show obvious change with increasing the sintering temperature. The fracture toughness of the MoSi2-SiCw composites showed change trend similar to the change trend of the flexural strength with increasing sintering temperature and time. The maximum fracture toughness of 5.8 MPa m(1/2) was greater than 3.3 MPa M-1/2 of monolithic MoSi2 by 76%. The increase of fracture toughness was due to whisker bridging, whisker pull-out and crack deflection around the whiskers. The hardness of the MoSi2-SiCw composites did not show an obvious change with the change of relative density due to the bridging effect of the SiC whiskers. (C) 2013 Elsevier Ltd. All rights reserved.