Annealing behavior of alumina dispersion-strengthened copper strips rolled under different conditions

Abstract

A study has been made of annealing behavior of a boron-added alumina dispersion-strengthened copper (ADSC) strip, Glidcop Al-25, and specimens fabricated by rolling of the strip by 25 to 28 pct under various conditions. All the specimens, including the starting strip, had similar microstructures consisting of microbands aligned parallel to the rolling direction. The textures of the specimens were characterized by ␤ fiber, which runs from the copper orientation {112}͗111͘ over the S orientation {123}͗634͘ to the brass orientation {110}͗112͘ in the Euler orientation space, with the intensities in the S and the brass components being higher than the copper component and with the S components having higher intensities than the brass component in the surface layers. When annealed at 1123 K for 1 hour, the center region of the starting strip and cold-rolled specimens underwent recrystallization, with recrystallization texture being approximated by {112}͗312͘, whereas the specimens rolled at 813 K did not undergo recrystallization through the thickness. These results have been discussed based on detailed microstructures and microtextures.

Recrystallization of Dispersion-Strengthened Copper Alloys

“…16. Identification of an existing large particle observed in the as-received strip (Kim & Lee, 2002) www.intechopen.com…”

“…Alumina DS copper alloys can be recrystallized when boron is added (Kim & Lee, 2001, 2002. Boron is often intentionally added as an oxygen scavenger during fabrication of the alloys (Gallagher et al, 1992).…”

“…Boron is often intentionally added as an oxygen scavenger during fabrication of the alloys (Gallagher et al, 1992). Long term annealing of boron-added alumina DS copper alloys results in an unexpected transformation from fine -Al 2 O 3 to coarse 9Al 2 O 3 -2B 2 O 3 with a concurrent recrystallization of the matrix to form a large and elongated grain structure (Kim & Lee, 2002). Whereas Ni-based DS alloys are used in a coarse-grained condition to increase high-temperature creep resistance (Gessinger, 1976;Stephens & Nix, 1985), key applications of alumina DS copper alloys require them to be in a fully workhardened state.…”

“…An alternative explanation is based on the assumption that coarse particles are sheared into finer particles during hot rolling (Kim & Lee, 2002). The shear strength of the particle might decrease with increasing temperature.…”

Obtaining of nanostructured powders for production of new dispersion strengthened sintered material in the system Cu-Al2O3

“…Svi pokušaji kvantifikacije uticaja parametara disperzije (zapreminski udeo, veličina čestica, međučestično rastojanje) na proces rekristalizacije se zasnivaju na raznim aproksimacijama [106]. Obično se polazi od nepromenljivog zapreminskog udela čestica, a variraju međučestično rastojanje za konstantnu veličinu čestica ili obrnuto.…”