Fabrication and Characterization of Nano-Zro2 Dispersed W-Based Alloys by Mechanical Alloying and Conventional Sintering

Abstract

Nanostructured tungsten (W) based alloy with the nominal compositions of 1.0 wt. % nano-ZrO2 dispersed W79Ni10Mo10 (in wt. %) was synthesized by mechanical alloying followed by compaction at 1GPa pressure for 5 mins and conventional sintering at 1500°C for 2 h in Argon atmosphere. The microstructure and evolution of phases during milling and consolidated products was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), High resolution transmission electron microscopy (HRTEM) and Energy dispersive spectroscopy (EDS). Minimum crystallite size of 28.6 nm and maximum lattice strain and dislocation density of 0.29% and 12.67 (1016/m2) respectively was achieved in W79Ni10Mo10(ZrO2)1 alloy at 20 h of milling. The lattice parameter of W in W79Ni10Mo10(ZrO2)1 alloy expanded upto 0.02% at 5 h of milling and contracted upto 0.20% at 20 h of milling. The hardness of the sintered alloy was 4.92 GPa with appreciable wear resistance