Nucleation of Dynamic Recrystallization at the Grain Boundaries of Copper Bicrystals

Hiromi Miura; Taku Sakai; R. Mogawa; John J. Jonas

doi:10.4028/www.scientific.net/MSF.558-559.457

Paper Titles

Effect of Niobium Addition on the Texture Formation of High Strength Cold-Rolled Low Carbon Steel Sheets
p.425

Grain Size in Mg Alloys: Recrystallization and Mechanical Consequences
p.433

Understanding Dynamic Recrystallization Behavior through a Delay Differential Equation Approach
p.441

Dynamic Recrystallization in Copper and Copper-Tin Alloys
p.449

Nucleation of Dynamic Recrystallization at the Grain Boundaries of Copper Bicrystals
p.457

Atomistic Processes of Phase Transformation and Dynamic Recrystallization during Hot-Working of Intermetallic Titanium Aluminides
p.465

Formation of Ultrafine Ferrite Grains during Interrupted Multi-Pass Deformation under Hot Torsion
p.471

Dynamic Recrystallization Mechanisms on Spot Welding of 6008 Aluminium Alloy to Steel by Friction Stir Welding
p.477

Investigation of Retained Strains during Multipass Deformation
p.485

HomeMaterials Science ForumMaterials Science Forum Vols. 558-559Nucleation of Dynamic Recrystallization at the...

Nucleation of Dynamic Recrystallization at the Grain Boundaries of Copper Bicrystals

Abstract:

Orientation-controlled copper bicrystals containing symmetrical 70o [0 0 1] tilt boundaries were deformed in tension at 923 K and at three initial strain rates from 4.2 x 10-5s-1 to 4.2 x 10-3s-1. The load was applied parallel to the grain boundary so as to eliminate grain boundary sliding. The nucleation of dynamic recrystallization (DRX) was investigated using optical microscopy and orientation imaging microscopy methods. After grain-boundary migration (GBM) and bulging, nuclei appeared behind the most deeply bulged grain boundary regions. The critical strain for nucleation was less than one-half of the peak strain and largely independent of the strain rate. At a fixed strain, nucleation is more frequent and the grain size finer as the strain rate is increased. All the nuclei were twin-related (Σ3) to the matrices. Furthermore, most of the twinning plane traces were parallel to the inactive slip traces of the bicrystals. This indicates that twin variant selection is essentially unaffected by dislocation motion. The observed mechanism of nucleation of DRX is discussed in relation to the occurrence of GBM and twinning.