SHEAR-INDUCED EXOTHERMIC CHEMICAL-REACTIONS

Authors
CHEN HC NESTERENKO VF LASALVIA JC MEYERS MA
Citation
Hc. Chen et al., SHEAR-INDUCED EXOTHERMIC CHEMICAL-REACTIONS, Journal de physique. IV, 7(C3), 1997, pp. 27-32
Citations number
19
Categorie Soggetti
Physics
Journal title
Journal de physique. IV → ACNP
ISSN journal
11554339
Volume
7
Issue
C3
Year of publication
1997
Pages
27 - 32
Database
ISI
SICI code
1155-4339(1997)7:C3<27:SEC>2.0.ZU;2-P
Abstract
The structure of controlled high-strain-rate shear bands generated in Ti-Si reactive powders has been investigated by means of the radial sy mmetric collapse of a thick-walled cylinder. Shear localization develo ped at global strains of 0.2-0.4 and a strain rate of 10(4) s(-1). Wit hin the shear bands, local shear strains were up to 100 and local shea r strain rates were 10(7) s(-1). Chemical reactions were initiated at these shear bands and propagated throughout the entire specimen under critical global strain conditions. A model for a periodic distribution of ''hot spots'' in reactive powders is proposed. It is possible to e stimate the reaction rate from the triangular unreacted regions formed by the shear localization process.