Synthesis and characterization of W80Ni10Mo10 alloy produced by mechanical alloying

Abstract

The present study aims at synthesis and characterization of nanostructured W80Ni10Mo10 (wt. %) alloy produced by mechanical alloying (MA). Elemental powders of tungsten (W), nickel (Ni), molybdenum (Mo) were subjected to mechanical attrition in a high energy planetary ball-mill using chrome steel as grinding media and toluene as a process control agent. The crystallite size and lattice strain of the nanostructured powders at different stages of milling (0 h to 20h) was calculated from the X-ray diffraction patterns (XRD). The crystallite size of W in W80Ni10Mo10 powder was reduced from 100 μm to 55 nm at 10 h and farther reduction to 40 nm at 20 h of milling with increase in lattice strain of 0.25% at 20 h of milling. The lattice parameter of tungsten showed initial expansion upto 0.03% at 10 h of milling and then contraction upto 0.04% at 20 h of milling. The scanning electron microscopy (SEM) also showed mixed morphology of W80Ni10Mo10 powders consisting spherical and elongated particles after 20 h of milling. SEM analysis also revealed that particle size reduced from 100 μm to 2 μm with an increase in the milling time from 0 to 20 hours. The dark-field Transmission Electron Microscopy (TEM) observations revealed that the crystallite size of W in milled W80Ni10Mo10 alloy is in good agreement with calculated crystallite size from XRD.