HARDNESS AND FRACTURE TOUGHNESS OF SiC-PREFORMS INFILTRATED WITH MoSi2

Composites consisting of molybdenum disilicide (MoSi2), molybdenum carbosilicide (Mo < or = 5Si3C < or = 1) and silicon carbide were prepared by carbon(gas)-MoSi2 (melt) infiltration of SiC preforms in an environment with carbon activity close to 1. Pure MoSi2 or a SiC-MoSi2 eutectic compositi...

Full description

Saved in:
Bibliographic Details
Published in:Key engineering materials 2001-05, Vol.223, p.215-219
Main Author: Panek, Z
Format: Article
Language:English
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Composites consisting of molybdenum disilicide (MoSi2), molybdenum carbosilicide (Mo < or = 5Si3C < or = 1) and silicon carbide were prepared by carbon(gas)-MoSi2 (melt) infiltration of SiC preforms in an environment with carbon activity close to 1. Pure MoSi2 or a SiC-MoSi2 eutectic composition was used as the liquid infiltrant. Carbon was incorporated into the SiC preform in the gas phase due to the temperature gradient between the graphite heating element and the preform. The low final porosity (1-3%) of the prepared composites was achieved by infiltration in a dynamic vacuum of about 50 Pa at temperatures between 1980 C and 2050 C. Higher values of hardness and fracture toughness were obtained for composites infiltrated using the SiC-MoSi2 eutectic composition. 7 refs.
ISSN:1013-9826