Grain-Size and Alloying Effects on the Pressure-Induced bcc-to-hcp Transition in Nanocrystalline Iron

Abstract

The pressure-induced bcc-to-hcp phase transformation has been studied by x-ray diffraction for bulk iron as well as nanocrystalline iron and a Fe₉₀Cu₁₀ alloy. The nanocrystalline material has a lower onset pressure and a larger pressure hysteresis than bulk iron. The non-random orientation of the nanocrystals is sensitive to shear stress in the high-pressure cell.