Experimental and atomistic simulation based study of W based alloys synthesized by mechanical alloying

• Nanostructured W90Mo10 and W80Ni10Mo10 alloy has been synthesized by mechanical alloying and argon purged sintering.
• Lattice parameter of W in both alloys expanded upto 10 h of milling and contracted beyond 10 to 20 h of milling.
• Higher hardness, strength, elongation and minimum wear depth is achieved in sintered W80Ni10Mo10 alloy.
• Atomistic simulation is performed to compare and understand the mechanism for improvement in plastic flow due to Ni addition.

The present research work represents the synthesis of nanostructured W based alloys with the nominal compositions of W90Mo10 and W80Ni10Mo10 (all in wt.%) by mechanical alloying and followed by conventional sintering at 1500 °C for 2 h in Ar atmosphere. The microstructure and evolution of phases during milling and consolidated products are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Energy dispersive spectroscopy (EDS). Crystallite size of 38.7 nm and 40 nm and lattice strain of 0.41% and 0.33% are achieved in W90Mo10 and W80Ni10Mo10 alloy respectively at 20 h of milling. The lattice parameter of all the investigated alloys shows initial expansion at 10 h of milling and then contraction at 20 h of milling. W80Ni10Mo10 shows maximum sintered density of 94.8% as compared to W90Mo10. The hardness as well as the compressive strength of W80Ni10Mo10 alloy records maximum value of 8.57 GPa and 1.18 GPa, respectively. The minimum wear depth is attained in W80Ni10Mo10 alloy to that of W90Mo10. Molecular dynamic simulation based study is also performed to reveal the mechanisms responsible for deformation. Atomistic simulation shows that addition of nickel lowers the flow stress and increases ductility of W-Mo alloy studied at nanoscale. Results of atomistic simulation based study correlates well with experimental analysis.

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