Is Ashby grain-boundary hardening model applicable for high strains?

Ashby晶界强化模型适用于高应变吗？（英文）

This work was undertaken to evaluate the applicability of the Ashby grain-boundary hardening model for a high strain range.To this end,Al Mg alloy with distinctly different grain sizes(~100μm vs^1μm)was cold-rolled to a true strain of^1.6 and the resulting dislocation densities were compared by using transmission electron microscopy.A minor difference revealed by the measurements suggested a violation of the Ashby’s model.This effect was attributed to a partial relaxation of strain constraints due to significant change of grain shape,development of texture and formation of pronounced substructure.

为了评估Ashby晶界强化模型在高应变范围内的适用性,将具有不同晶粒尺寸的Al Mg合金(~100μm与~1μm)冷轧至真应变约为1.6,并采用透射电镜观察比较两种合金的位错密度。测量结果显示的微小差异表明其违背了Ashby模型,这是由晶粒形状的显著变化、织构·演化和形成明显的亚结构等因素造成应变约束的局部松弛导致。