Accession Number:

ADA326120

Title:

Feasibility for Improving Ambient Temperature Toughness of MOSI2 and its Composites.

Descriptive Note:

Final rept. 1 Mar 94-1 Mar 97,

Corporate Author:

STATE UNIV OF NEW YORK AT STONY BROOK DEPT OF MATERIALS SCIENCE AND ENGINEERIN G

Personal Author(s):

• Newman, A.
• Sampath, S.
• Herman, H.

Report Date:

1997-03-01

Pagination or Media Count:

22.0

Abstract:

Due to its high melting point and oxidation resistance, molybdenum disilicide MoSi2 is a candidate for high temperature structural components. However, in order for MoSi2 to be applicable for these applications, the high temperature creep resistance and low temperature fracture toughness of the compound need to be substantially improved. In this ONR sponsored study, we are examining the effects of processing on the resulting microstructure and properties of reinforced and unreinforced MoSi2. Samples have been obtained from several laboratories with the goal of determining the effects of purity and processing. The results indicate that a finer grain size in combination with the addition of small particles, whether silica, SiC, or precipitates, contributes to the improvement in the materials low temperature fracture toughness.

Descriptors:

• *COMPOSITE MATERIALS
• *SILICON CARBIDES
• *MOLYBDENUM COMPOUNDS
• *STRUCTURAL COMPONENTS
• *REINFORCEMENT(STRUCTURES)
• PARTICLE SIZE
• MICROSTRUCTURE
• TOUGHNESS
• GRAIN SIZE
• FRACTURE(MECHANICS)
• OXIDATION RESISTANCE
• MELTING POINT
• SILICIDES
• SILICA GLASS
• CREEP STRENGTH

Subject Categories:

• Laminates and Composite Materials
• Manufacturing and Industrial Engineering and Control of Production Systems
• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE