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Accession Number:
AD0610468
Title:
STUDY OF LOCAL-ORDER AND SOLID-SOLUTION STRENGTHENING IN COLUMBIUM ALLOYS.
Corporate Author:
BATTELLE MEMORIAL INST COLUMBUS OHIO
Report Date:
1965-01-22
Abstract:
This research program attempted to establish whether Fishers local-order solution-strengthening mechanism is of importance in columbium-base alloys by correlating X-ray diffuse-scattering determinations of local order with mechanical properties. Results of the project indicated that local order can make a significant strengthening contribution, but other mechanisms can also dominate. By X-ray diffuse-scattering powder-pattern analysis, it has been determined that Cb-V alloys are nearly random. The atom-size effect was also determined, indicating there is a size accommodation in solution such that, instead of the 8.5 per cent size difference of the pure components, there is only about a 3 per cent difference. The results are discussed in terms of atom-size-accommodation mechanisms, ordering driving force, and solidsolution strengthening. Solid-solution strengthening due to atom-size difference in a substitutional binary alloy is shown to depend on composition fluctuations. An elastic model of binary solid solutions is extended to include short-range order SRO strain relaxation. It is shown that typically about half of the atom dilation and strain energy can be relaxed by SRO.
Descriptive Note:
Rept. for 1 May 63-30 Apr 64,
Pages:
0037
Contract Number:
AF33 657 8844
File Size:
0.00MB
