A commercial Al-7034 alloy, produced by spray-casting and with an initial grain size of ∼ 2.1 μm, was subjected to equal-channel angular pressing (ECAP) at 473 K to a total of six passes, equivalent to an imposed strain of ∼ 6. In the as-pressed condition, there was a reasonably homogeneous microstructure of equiaxed grains with an average grain size of ∼ 0.3 μm. This alloy contains MgZn2 and Al3Zr precipitates, and these precipitates serve to inhibit grain growth so that an ultrafine submicrometer grain size was retained at temperatures up to and above 600 K. Tensile testing at 623 K revealed the occurrence of superplastic elongations in the as-pressed material with a maximum elongation of > 500% when using an initial strain rate of 1 × 10-2 s-1.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering