Accession Number:

AD0261171

Title:

KINKING AND THE FRACTURE OF IONIC SOLIDS

Descriptive Note:

Corporate Author:

HONEYWELL RESEARCH CENTER HOPKINS MINN

Personal Author(s):

Report Date:

1961-06-01

Pagination or Media Count:

1.0

Abstract:

A single crystal undergoing plastic bending develops constraints due to the gradient in lateral contraction across the beam. These constraints result in lateral stresses which may be relieved by the process of anticlastic kinking. Temperature affects the structure of kink boundaries and their subsequent role in initiating fracture. At high temperatures the resultant dislocations are ineffective barriers to slip and the crystals are ductile. At low temperatures the resultant dislocations provide strong barriers to slip and cracks nucleate at the kink boundary. At very low temperatures fracture occurs before the second set of glide dislocations have been activated to generate anticlastic kinks. Relaxation of the lateral stress results in a complex fracture. Compatible observations of the change in fracture behavior under bending over different temperature ranges have been made on a number of ionic solids. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE