E.D. Wang

The effect of cumulative large plastic strain on the structure and properties of a Cu–Zn alloy

Abstract A Cu–38%Zn alloy has been deformed to large strain by a new method, and the change of structure has been investigated. The method is called equal-channel angular pressing (ECAP). After deformation, the microstructure has been changed greatly, while the macrostructure, such as the size and distribution of the second phase and the original grain boundaries have been changed a little. As the equivalent true strain is increased to 10, the average crystallite size is decreased to 0.4 μm according to transmission electron microscopy (TEM) observation and X-ray diffraction results. At the same time, the Vickers hardness is increased from 71 to 220.

A further study on effect of large strain on structure and properties of a Cu–Zn alloy

Abstract A Cu–38%Zn alloy has been deeply deformed to a very large strain by using the method of equal-cross section lateral extrusion (ECSLE), and the influence of the process on the structure and properties of the alloy have been investigated. It is revealed by XRD analysis that the average crystallite size of the matrix phase decreases to 100–150 nm, when the equivalent true strain is increased to 80, while the size, shape and distribution of the second phase have been changed little, which displays a characteristic of ECSLE deformation.

Critical Rolling Process Parameters for Dynamic Recrystallization Behavior of AZ31 Magnesium Alloy Sheets

In this work, the influence of various rolling temperatures and thickness reductions on the dynamic recrystallization (DRX) behavior of AZ31 magnesium alloy sheets was investigated. Meanwhile, the texture variation controlled by DRX behavior was analyzed. Results suggested that, with the help of DRX behavior, reasonable matching of rolling temperature and thickness reduction could effectively refine the grain size and improve the microstructure homogeneity. Using the grain refinement and microstructure homogeneity as the reference, the critical rolling process parameters were 400 °C—30%, 300 °C—30%, and 250 °C—40% in the present work. In terms of basal texture variation, the occurrence of twins produced the largest maximum texture intensity. However, for the sheets with DRX behavior, the maximum texture intensity decreased sharply, but would steadily increase with the growth of DRXed grain. Additionally, for DRXed grains, the <11-20>//RD (RD: rolling direction) grains would gradually annex the <10-10>//RD grains with the growth of DRXed grains, which finally made their texture component become the dominant texture state. However, when the deformation continued, the <10-10> in DRXed grains would rotate toward the RD again. Weighted by the fracture elongation of AZ31 magnesium alloy sheet, the critical thickness reductions were 30–40% under the rolling temperature of 400 °C.