Citation

Harmeling D, Johnson A. Accid. Reconstr. J. 1993; 5(5): 52-57.

Copyright

(Copyright © 1993, Accident Reconstruction Journal)

DOI

unavailable

PMID

unavailable

Abstract

For many years lamp filaments of vehicles involved in nighttime collisions have been examined to try to determine which were incandescent at the moment of impact. Tungsten exhibits a ductile-brittle transition and it is usually assumed in interpreting lamp filament-observations that an unlit filament is brittle and an incandescent filament ductile. Thus, if a filament is observed to have undergone fragmentation without plastic deformation it is concluded that it was not incandescent at the time of the collision. If it is observed to have distended plastically it is assumed that it was incandescent. If the bulb's glass envelope breaks during collision, oxidation of a filament will be evident if it was incandescent or at least well above ambient temperature. This is a review of ductile-brittle transition in metals.