Leaching Effect on Multiple Surfaces of a Single Grain Decagonal Al-Ni-Co Quasicrystal

Abstract

We have studied the eect of leaching treatments on the surface microstructure and chemical composition on the two dierent twofold surfaces, (10000) and (10100), and the tenfold surface (00001) of a decagonal (d-) AlNiCo quasicrystal. A sample exposing the three surfaces was leached with NaOH solution and then studied using atomic force microscopy and scanning electron microscopy combined with energy dispersive X-ray analysis. The leaching treatment preferentially removes the Al present in the crystal surface leaving a mixture of transition metal and their associated oxides. The high symmetry, tenfold axis was found to be less resistant to leaching than either of the twofold axes, providing further information regarding the eect of crystallographic direction on leaching kinetic.