Formation and thermal stability of nanocrystalline CuTiNi prepared by mechanical alloying

Abstract

Abstract The formation and thermal stability of nanocrystalline Cu70Ti20Ni10 powders by mechanical alloying have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The composition (at.%) of the sample has been examined by energy dispersive X-ray analysis (EDX) attached to SEM. After milling, the material was found to have a disordered f.c.c. structure, with nanocrystalline grain sizes around 4.7 nm determined from the f.c.c. (111) diffraction peak. The DSC signal decreases monotonically with isothermal transformation owing to grain growth. The crystal grains do not grow by heating until the intermetallic TiCu3 and NiTi phases nucleate at 450°C.