Accession Number : AD0713737

Title :   GRAIN REFINEMENT IN UNDERCOOLED COPPER,

Corporate Author : DEFENCE STANDARDS LABS MARIBYRNONG (AUSTRALIA)

Personal Author(s) : Jones,B. L. ; Weston,G. M.

Report Date : 22 MAY 1970

Pagination or Media Count : 4

Abstract : It was shown possible to obtain a fine equiaxed grain structure throughout a copper ingot containing 0.015 wt % oxygen if prior to nucleation the ingot is undercooled by 55 deg C. After undercoolings of 38 deg C or less the ingots had structures consisting of two separate zones of fine and coarse grains, and the proportion of fine grains decreased with increasing temperature of nucleation. The fine grain structure is attributed to a dendrite remelting process which arises during recalescence in the presence of approximately 150 ppm oxygen. In contrast to earlier experiments involving copper of higher oxygen content and nucleated at larger undercoolings, little evidence of recrystallization was found in these present ingots. It is therefore suggested that recrystallization in high oxygen ingots is connected with the large amount of undercooling applied rather than with the presence of oxygen. (Author)

Descriptors :   (*COPPER, GRAIN STRUCTURES(METALLURGY)), COOLING, RECRYSTALLIZATION, AUSTRALIA

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE