Autor: |
Rao, K. V., Polonis, D. H. |
Zdroj: |
Journal of Materials Science; February 1985, Vol. 20 Issue: 2 p491-500, 10p |
Abstrakt: |
Transmission electron microscopy techniques have been employed to study the microstructural changes accompanying deformation and spallation during the dynamic loading of Cu-Co dispersion alloys. Alloys aged to produce coherent precipitate particles exhibited a loss of coherency and apparent precipitate enlargement after being subjected to dynamic loading conditions. Over-aged alloys containing incoherent precipitates exhibited precipitate growth, dislocation entanglements and void initiation in the matrix adjacent to precipitate-matrix interfaces. The superior spallation resistance of alloys containing fine coherent precipitates is attributed to the difficulty of void nucleation at low misfit interfaces which can accommodate dislocation cutting and offer preferred sinks for excess vacancies. A model based on the generation of excess lattice vacancies during dynamic loading is described to account for the observation of particle enlargement and loss of coherency, as well as the preferred initiation of voids adjacent to incoherent particles. |
Databáze: |
Supplemental Index |
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