Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1581453 | Materials Science and Engineering: A | 2008 | 7 Pages |
Abstract
Creep results of a dispersion-strengthened nominal-composition Cu-2.5Â vol.%Ti-2.5Â vol.%Al alloy, and the adjustment of those results to existing creep models, are presented. The alloy was prepared by reaction milling; its microstructural characterization by transmission electron microscopy had been recently reported elsewhere. Creep tests were here performed at 773, 973 and 1123Â K, under loads that produced steady-state creep rates between 9Â ÃÂ 10â7 and 2Â ÃÂ 10â4Â sâ1. Two deformation models, available in the literature, were considered: dislocation creep, where the strain rate is controlled by the dislocation-particle interaction within the grains, and diffusional creep, controlled by the interaction between grain-boundary dislocations and particles. In all creep experiments the alloy exhibited high values of the apparent stress exponent, as typical for dispersion-strengthened alloys. Through model adjustment, the operating creep mechanisms where determined: at 773 and 1123Â K, creep is controlled by dislocation/particle interactions taking place in the matrix and in grain boundaries, respectively, while at the intermediate temperature of 973Â K, controlling dislocation-particle interactions would occur both in the matrix and in grain boundaries.
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Physical Sciences and Engineering
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Authors
Rodrigo G. Espinoza, Rodrigo H. Palma, Aquiles O. Sepúlveda, Alejandro Zúñiga,