Accession Number : AD0651508

Title :   A STUDY OF THE EARLY STAGES OF PLASTIC DEFORMATIONS.

Descriptive Note : Final rept., Jan 65-Jan 67,

Corporate Author : PENNSYLVANIA UNIV PHILADELPHIA SCHOOL OF METALLURGICAL ENGINEERING

Personal Author(s) : Brown,Norman

Report Date : 01 MAY 1967

Pagination or Media Count : 82

Abstract : Recent advances in the measurement of the early stages of plastic deformation are reviewed, with emphasis on the capacitance gauge technique. The parameters measured and the type of information obtained in microstrain experiments are discussed, and examples of applications to various materials and deformation mechanisms are presented. Dislocation damping during a slow microstrain experiment involves at least two mechanisms, one of which depends on prestrain. The mechanism that depends on prestrain has been attributed to the existence of ripples in the long range internal stress field. A theory has been presented for the way that ripples in a long range internal stress field produces dislocation damping. Experimental observations on nickel have been interpreted in terms of the theory. (Author)

Descriptors :   (*DEFORMATION, STRAIN(MECHANICS)), (*DISLOCATIONS, DAMPING), PLASTIC PROPERTIES, STRESSES, INTERNAL FRICTION, THEORY, NICKEL, IRON ALLOYS, SILICON ALLOYS

Subject Categories : Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE