Effect of carbon addition on elevated temperature crack growth resistance in (Mo,W)Si[sub 2]-SiC[sub p] composite

Journal Article · Sat Oct 01 00:00:00 EDT 1994 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb04661.x· OSTI ID:6765138

Ramamurty, U ^[1]; Suresh, S ^[2]; Petrovic, J J ^[3]

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1. Brown Univ., Providence, RI (United States). Division of Engineering
2. Massachusetts Inst. of Technology, Cambridge, MA (United States). Dept. of Materials Science and Engineering
3. Los Alamos National Lab., NM (United States). Materials Science and Technology Division

Experimental results on subcritical crack growth behavior of hot-pressed MoSi[sub 2]-50 mol% WSi[sub 2] alloy reinforced with 30 vol% SiC particles in the temperature range 1,200--1,300 C are presented. The effect of 2 wt % C addition on the stable crack growth resistance of this composite was investigated under both static and cyclic loading conditions. The results indicate that the addition off carbon to the composite improves the subcritical crack growth resistance under both static and cyclic loads and increases the elevated temperature capabilities of the (Mo, W) Si[sub 2] composite. Increasing the temperature from 1,200 to 1,300 C is found to increase the crack growth velocities with a concomitant decrease in the crack growth initiation thresholds. Electron microscopy of the crack-tip region indicates that the stable crack growth process is influenced primarily by interfacial cavitation. At 1,300 C, deformation processes such as twinning of the SiC particles and dislocation motion within the matrix grains appear to play an active role in determining the crack growth kinetics. The role of glassy phase in influencing the high-temperature fracture behavior and its implications for design of the microstructure of the brittle materials are discussed.

• OSTI ID: 6765138
• Journal Information: Journal of the American Ceramic Society; (United States), Vol. 77:10; ISSN 0002-7820
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBON
METALLURGICAL EFFECTS
COMPOSITE MATERIALS
CRACK PROPAGATION
MOLYBDENUM SILICIDES
SILICON CARBIDES
TUNGSTEN SILICIDES
EXPERIMENTAL DATA
HEAT RESISTANT MATERIALS
CARBIDES
CARBON COMPOUNDS
DATA
ELEMENTS
INFORMATION
MATERIALS
MOLYBDENUM COMPOUNDS
NONMETALS
NUMERICAL DATA
REFRACTORY METAL COMPOUNDS
SILICIDES
SILICON COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN COMPOUNDS
360603* - Materials- Properties