Abstract
The mechanical properties as hardness, bending strength, fracture toughness, and creep of a monolithic molybdenium disilicide and a MoSi₂+SiC composite have been investigated. The bending strength was measured in four-point bending, the fracture toughness using single edge V-notched specimens at room temperature. The creep experiment was carried out in fourpoint bending mode in the temperature range from 1100°C to 1200°C in air. The influence of high-temperature heat treatments in air at 1400°C and 1550°C for 100 h on the bending strength of MoSi₂ at room temperature has been investigated, too.
The hardness and fracture toughness of MoSi₂+SiC composites were slightly improved by the incorporated SiC particles into the MoSi₂ matrix. The strength values of composites were relatively low because of the presence of defects in their microstructure. The creep resistance of MoSi₂+20vol.%SiC composite was significantly improved in comparison with the monolithic MoSi₂. Heat treatment at 1400°C had no influence on the strength but a heat treatment at 1550°C significantly decreased the strength due to the formation of large pores in the bulk of the material.

Key words
MoSi₂, microstructure, fracture, mechanical properties

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