Microstructure and properties of copper and aluminum alloy 3003 heavily worked by equal channel angular extrusion |
| |
Authors: | Stephane Ferrasse K Ted Hartwig Ramon E Goforth Vladimir M Segal |
| |
Affiliation: | (1) R&D Engineer with SOLLAC (USINOR SACILOR Group) in Dunkerque, France;(2) the Department of Mechanical Engineering, Texas A&M University, 77843-3123 College Station, TX;(3) Johnson Matthey Electronics, 99216 Spokane, WA |
| |
Abstract: | A technique invented in the former Soviet Union and recently introduced in the United States, called equal channel angular
extrusion (ECAE), produces intense and uniform deformation by simple shear and is applied to 25 × 25 × 152-mm billets of Cu
101 and Al 3003. Microcrystalline structures with a grain size of 0.2 to 0.4 μm are created during room-temperature multipass
ECAE deformation for true strains lying in the range ε=2.31 to 9.24. Evidence shows that intense simple shear deformation
promotes dynamic or continuous recrystallization by subgrain rotation. The effects of the number of extrusion passes and deformation
route for Cu 101, and the deformation route after four passes for Al 3003, are studied. Increasing the number of ECAE passes
in Cu 101 causes strength to reach saturation and grain refinement stabilization after four passes (true strain of 4.68),
and subgrain misorientation to increase as the number of passes increases. For multipass ECAE with billet orientation constant
(route A) or rotated 90 deg between all passes (route B), two levels of structures are created inside the original grains:
shear bands (first level) and very fine subgrains (second level) within the shear bands. For a billet rotation of 180 deg
between passes (route C), an unusual event is observed. At each even numbered pass, shear bands nearly disappear and only
subgrains are present inside the original grains. Route B gives the highest strength, whereas route C produces a more equiaxed
and stable microstructure. Subsequent static recrystallization increases the average grain size to 5 to 10 μm. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|