Thermal stresses in metal matrix composites studied by internal friction
- Ecole Polytechnique Federale de Lausanne (Switzerland). Inst. de Genie Atomique
Thermal stresses in metal matrix composites (MMC) can induce plastic deformation and damage accumulation in the region close to the reinforcements. In this connection, Al-4% Cu-based MMC reinforced with 10, 20 and 30% Al{sub 2}O{sub 3} short fibers were characterized by internal friction (IF) measurements. As a function of the temperature, a maximum of damping has been observed in the composites at ca 150 K during cooling. This maximum is absent in the corresponding unreinforced AlCu alloy. The maximum is attributed to the generation and motion of dislocations produced by high thermal stresses at metal-fiber interfaces. The height of the maximum is found to be an index of the extent of relaxation of thermal stresses by the plastic deformation of the metal matrix. IF measurements have allowed the authors to identify whether plastic flow in the matrix or damage accumulation at matrix-fiber interfaces take place for different composites.
- OSTI ID:
- 417834
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: 12 Vol. 44; ISSN 1359-6454; ISSN ACMAFD
- Country of Publication:
- United States
- Language:
- English
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