Optimizing the homogenization technique for graphene nanoplatelet/yttria tetragonal zirconia composites: Influence on the microstructure and the electrical conductivity

3 mol% yttria tetragonal zirconia polycrystalline (3YTZP) ceramic composite powders with 10 vol% nominal content of graphene nanoplatelets (GNPs) were prepared using four different homogenization routines: dispersion of the powder mixture by ultrasonication in isopropyl alcohol, homogenization in a high-energy planetary ball mill in wet or dry conditions after ultrasonication, and milling of the powders…

Nanostructured vanadium carbonitride prepared by combustion synthesis during mechanical milling

Vanadium carbonitride (VCN) nanoparticles were synthesized by a mechanically induced magnesiothermic combustion in a Mg/V2O5/C3H6N6 system. Initial materials ignited after a short milling time of 6 min. Various characterizations such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HRTEM) and elemental mapping confirmed that the product of…

Effects of milling time, sintering temperature, Al content on the chemical nature, microhardness and microstructure of mechanochemically synthesized FeCoNiCrMn high entropy alloy

FeCoNiCrMn(Al)-based powdered high entropy alloys were synthesized by a short time mechanical alloying process in a high energy planetary ball milling from mixtures of elemental powders, and subsequently sintered by a pressureless procedure. The composition and microstructure of the HEA phases before and after the sintering process were studied by X-ray diffraction, energy dispersive X-ray…

Characterization of of mechanosynthesized Bi1-xSmxFeO3 samples unencumbered by secondary phases or compositional inhomogeneity

High-quality samples, in terms of phase purity and dielectric properties, of composition Bi1-xSmxFeO3 (0.05 <= x <= 0.20) have for the first time been prepared by mechanosynthesis. Close inspection of the powder diffraction data, analysis via Rietveld refinement and TEM microscopy demonstrates that the Bi1-xSmxFeO3 samples contain only perovskite phases. Additionally, by a combination of…

Effect of the impact energy on the chemical homogeneity of a (Ti,Ta,Nb)(C,N) solid solution obtained via a mechanically induced self-sustaining reaction

A titanium-tantalum-niobium carbonitride solid solution, (Ti,Ta,Nb)(C,N), was synthesised in a planetary mill via a mechanochemical process that involves a mechanically induced self-sustaining reaction (MSR) from stoichiometric Ti/Ta/Nb/C mixtures that are milled under a nitrogen atmosphere. The influence of the spinning rate of the planetary mill, which determines the impact energy of the milling process, on…