Mechanically induced phase transformation in Al-Cu- Fe-Cr decagonal quasicrystalline alloy by high-energy ball milling

Abstract

In the present investigation, an Al-Cu-Fe-Cr decagonal quasicrystalline alloy synthesized by a slow cooling technique, has been mechanically milled in a high-energy ball mill for various times ranging up to 100 h under liquid hexane medium at the speed of 400 rpm with a ball to powder ratio of 40:1. After milling, the milled product has been characterized in order to understand the evolution of the various metastable phases by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Powders milled for more than 10 h contained predominantly the B2-type crystalline phase with a lattice parameter of ~ 0.29 nm. No amorphous phase could be identified after a prolonged milling up to 100 h. The disordering in the transformed crystalline phased could be observed. The mechanical stability during milling and the evolution nano phases will be discussed with reference to their relative stability. © CSIR-National Metallurgical Laboratory, Jamshedpur-831007, India, 2011.