Accession Number : AD0726207

Title :   The Dislocation Cell IZE AND Dislocation Density in Copper Deformed at Temperatures between 25 and 700 Degrees C.

Descriptive Note : Technical rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF METALLURGY AND MATERIALS SCIENCE

Personal Author(s) : Staker,Michael R. ; Holt,David L.

Report Date : JUN 1971

Pagination or Media Count : 41

Abstract : A dislocation cell structure was developed in polycrystalline OFHC copper by deforming tensile specimens 10 percent, one at each of the following temperatures: 25, 250, 400, 500, 550, 600, 650 and 700C. The dislocation cell size and the dislocation density were measured by transmission electron microscopy. The mean cell diameter increased with increasing temperature from 1.4 micrometers at 25C to 6.0 micrometers at 700C. The dislocation density rho decreased with increasing temperature, from 118.0 x 10 to the 8th power cm/cc at 25C to 10 to the 8th power cm/cc at 700C. The thickness of the cell walls decreased with increasing temperature of deformation. It was found that the mean cell diameter d was related to the dislocation density rho through the relation d = 16.2 rho to the -1/2 power. The occurrence of such a relation supports a theory in the literature of dislocation cell formation. The flow stress tau was given by tau = 10.5 Gb/d and tau = .575 Gb rho to the 1/2 power where G is the shear modulus and b is the Burgers vector. (Author)

Descriptors :   (*COPPER, *DEFORMATION), (*DISLOCATIONS, DENSITY), HIGH TEMPERATURE, ELECTRON MICROSCOPY, FOILS(MATERIALS)

Subject Categories : Metallurgy and Metallography
      Crystallography
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE