Synthesis of Nano-dispersed TiO2 Zirconium Based Alloy by
Mechanical Alloying

Abstract

The present work aims to improve the mechanical properties of Zr- alloy (Fe-30-Ni-20-Mo-4 TiO2-2-Zr-44) (all are in wt. %) synthesized by mechanical alloying and consolidated by conventional sintering. A uniform dispersion of TiO2 tends to improve the mechanical properties of the present alloys. The current alloys show improvement of hardness value which is 1-1.5 times higher than that of the conventional zircaloy. For this purpose, pure elemental powders of Zr, Ni, Fe, Mo and TiO2 were blended and milled in a planetary ball mill for 20 h and sintered at 1400°C for 2 h in argon atmosphere. Phase evolution of milled powders at different stages of milling (0h, 1h, 5h, 10h, 15h and 20h) and after sintering of the current alloy were analyzed by X- ray diffraction techniques. The grain morphology or crystallite size of various stages of milled powders was characterized by scanning electron microscope. The crystallite size, lattice strain and lattice parameters were analyzed by Williamson-Hall method. The crystallite size decreases rapidly up to 5hours of milling and becomes almost constant with further milling. Addition of TiO2 (2 wt %) in the matrix improves the hardness. This is due to the high modulus of elasticity of TiO2.