Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2013-11-01

Journal: INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS

Included Journals: Scopus、EI、SCIE

Volume: 41

Page Number: 489-494

ISSN: 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.