Journal of advanced materials and processing
Volume:8 Issue: 4, Autumn 2020

Considering slab method, a three-dimensional analytical model was adopted to evaluate the rolling pressure, force and torque in symmetrical wire flat rolling. Due to the effectiveness of the shear friction model to express the frictional state in the bulk metal forming, thus, it was used to define in slab formulation. In this paper, the plains strain condition no longer is valid and, the strain on z direction must also be taken into account in calculations. The resultant differential equations were solved numerically by Rung Kutta method and MATLAB software. It was concluded that as shear factor rises in the range of o.4

Aluminum matrix composites has recently gained increased attention for structural applications in many industries due to their excellent properties. In this research, machining scraps of coarse-grained Al2024-T3 alloy were used to prepare nanostructured Al2024 alloy and Al2024-2wt.%TiO2 nanocomposite. Then, tribological behavior of bulk nanostructured Al2024 alloy and Al2024-2wt.%TiO2 nanocomposite, produced by 10 h of mechanical alloying and subsequent hot-pressing at 500 C for 20 min, was investigated. Hardness measurements on the samples revealed that the hardness value of mechanically alloyed and hot-pressed Al2024 alloy reached a value of  198 HV, which was  41% higher than that for the initial coarse-grained Al2024-T3 alloy (140 HV). The average hardness values of Al2024-2wt.%TiO2 nanocomposite was found to be 238 HV, which showed ~ 20% increase compared with that for the nanostructured Al2024 alloy. The wear resistance of samples changed in the order of coarse-grained Al2024 alloy

The effects of micro-addition by rare earth (RE) elements (via cerium-based mischmetal) and hot deformation (via extrusion process) on the microstructure and mechanical properties of Mg-0.5Zn-0.5Zr alloy were studied. Optical microscopy, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and tensile testing were used for characterization of alloys in the as-cast and wrought conditions. It was found that the addition of 0.5 wt% RE combined with the hot extrusion process could remarkably refine the grain size from 1320 µm for the as-cast Mg-0.5Zn-0.5Zr alloy to the recrystallized grain size of 1.3 µm for the extruded Mg-0.5Zn-0.5Zr-0.5RE alloy. Compared to the as-cast counterparts, the ultimate tensile strength (UTS) and total elongation to failure were significantly enhanced by the extrusion process. Quantitatively, the UTS of ~ 300 MPa with the total elongation of ~ 18% was obtained for the extruded Mg-0.5Zn-0.5Zr-0.5RE alloy, which reveals the favorable effects of the ultra grain refinement on the enhancement of the mechanical properties of magnesium alloys.

Steelmaking slags are known as the secondary product of steel making process. Regarding the high rate of slag production and the existence of a noticeable amount of toxic and valuable metals such as vanadium in this material; recovery of vanadium from this product is necessary. In this study, steel making converter slag (containing about 1.96 wt.% V2O5) was ground to a mean size of 85 µm, and recovery of vanadium was carried out using acetic acid leaching. The effects of time (in the range of 0 to 120 min) and temperature (in the range of 0 to 80 ⁰C) in fixed acetic acid concentration (1 molal) and solid to liquid weight ratio (one gram slag in 200 ml) on the leaching process were investigated. The results showed that the increase in time and decrease of temperature (activation energy was equal to -11.4 kJ/mol) increases vanadium leaching efficiency. Maximum leaching efficiency was reached at 0 ⁰C and 90 min. Kinetics studies showed that heat diffusion through the solid layer is the controlling step of vanadium dissolution in acetic acid. Furthermore, thermal conductivity (ka) decreases by increasing temperature (ka=21877.6/T3), so the heat moves away from the reaction zone to the particle's surface at a slower rate.

The study of the exotic bound states in atomically thin semiconductors with a transition metal atom has attracted a great deal of interest in quantum field theory. The reality of transition metal dichalcogenide monolayer materials has been the subject of intense concern among theoreticians and experimenters in recent years. To obtain transition metal dichalcogenide monolayer materials with specific properties; it is extremely important to develop particular strategies to obtain specific exotic structures. These exotic structures are considered to be in a two-particle/quasiparticle bound state: exciton and biexciton (exciton-exciton), exciton-polariton, polariton-phonon. Quantum field theory, in its widest sense, is a method to control and achieve reasonable goals. Control of such states enables the control of properties and access to a range of quantum properties, otherwise inaccessible. The relativistic mass spectrum and relativistic constituent mass of particles in monolayer transition metal dichalcogenide monolayer materials have been calculated using the relativistic Schrödinger equation with strong Coulomb-type potential between the electron and hole. The ground state of the transition metal dichalcogenide monolayer has been studied. Therefore, the investigation may indicate promising applications in quantum information processing and electronic device technologies based on the semiconductor quantum dots system.

The structural and magnetic properties of the polyethylene glycol (PEG) coated nickel spinel ferrite (NiFe2O4) nanoparticles have been reported in the present study. NiFe2O4 nanoparticles were prepared by solution plasma method using KOH + Na2Co3 as electrolyte. The prepared powder of nickel ferrite nanoparticles was annealed at 800 ˚C for two h and used for further study. The X-ray analysis confirmed the formation of a cubic spinel single-phase structure. The crystallite size, lattice parameter, and X-ray density of the PEG-coated NiFe2O4 nanoparticles were calculated using XRD data. TEM and FTIR studies revealed the presence of PEG on nickel ferrite nanoparticles and reduced agglomeration in the NiFe2O4 nanoparticles. The pulse-field hysteresis loop tracer technique studied the magnetic properties at room temperature. The magnetic parameters such as saturation magnetization, remanence magnetization, and coercivity have been obtained. These magnetic parameters were get decreased by PEG coating.