Journal of advanced materials and processing
Volume:9 Issue: 3, Summer 2021

The present study develops a semi-instantaneous baseline damage identification approach to identify the delamination damage. An active sensing network with (Ba0.95Ca0.05)(Ti0.91Sn0.09)O3 (BCTS) lead-free piezoelectric transducers that were mounted on the two undamaged and damaged (with the delamination) plates. The wavelet transform was used for extracting the energy ratio change which is an effective and robust characteristic from the collected time-domain signals. The “identicality coefficient” (IC) was obtained for each sensing path under pristine structural conditions and used to eliminate any inequalities in the signals of each path. The output wave signals of samples were investigated by experiment and the finite element method. The values of the index produced by damages were significant against the threshold value set. The errors were less than 4%, which may be related to the linear relationship considered for the DI and delamination damage. A comparative of sensing paths showed a significant difference between both healthy and damaged samples. The delaminated damage was detected because the delamination phenomenon increased the amplitude of the wave and the wave energy. The comparison of the “damage index” (DI) values of six sensing paths showed that the path with delamination damage had the highest DI value i.e., 0.92 and then the sensing paths closest to the damage showed the highest DI values (DI=0.67). The path with a distance farther from the damage shows DI=0.09. The other DI values of other sensing paths were close to zero (DI=0) due to no damage.

In this study effect of active material particle size distribution (PSD) on TiNb2O7 electrodes and their performance were evaluated. To determine the effect of PSD, have focused on the performance of the electrode, which is mainly affected by the performance of individual particles and their interaction. For this purpose, TiNb2O7 was successfully synthesized by mechanochemical method and post-annealing, as an anode material for lithium-ion batteries. Phase identifications and microstructure characterization was carried out by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) to identify the phases and evaluate the morphology of the synthesized samples. The charging and discharging tests were conducted using a battery-analyzing device for evaluating the electrochemical properties of the fabricated anodes. Eventually, at faster charging rates, the electrochemical performance was found to be improved when smaller active material particle size distribution was used. Differences in particles size distributions resulted in variable discharge capacities so that the sample with particle size higher than 25 microns (>25 μm) showed a capacity of 19 mAh/g after 179 cycles, which had a lower capacity than their sample with particle size less than 25 microns (<25 μm). The final capacity of the sample with a particle size less than 25 microns is 72 mAh/g.

The 316L nickel-chrome molybdenum austenitic stainless steel is commonly employed in various industries. This type of steel is particularly of interest in chemical industries, especially in harsh and corrosive environmental conditions. Although 316L stainless steel has good mechanical and corrosive characteristics, it fails to perform well in chlorine-containing aqueous environments. To overcome this issue, a Ni-La-Cr-Fe layer is applied to the 316L steel using the electroplating method. In addition, the reverse pulse plating method is used to control the ion deposition kinetics. The plating current application duration (on-time), the current disruption duration (off-time), and (TRev) are the control parameters of the duration and polarity of the pulse. Finally, the coated layer acquires an average thickness of 6.83 after applying on-time and off-time repeatedly and performing SEM and polarization tests in 1.5% solution at 50 Celcius degrees. Furthermore, the desired surface morphology is achieved, and corrosion resistance is 160 times higher than 316 bare steel. Applying the reverse pulse plating method, adding beneficial compounds of saccharin and SDS, and using lanthanum chloride in the plating bath are the essential reasons to successfully add a coating layer on the 316 bare steel.

In this study, Pd-Co alloying nanoparticles supported on reduced graphene oxide (rGO) were synthesized and characterized by various techniques such as field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray (EDX), X-ray diffraction (XRD), and Raman spectra. The prepared Pd-Co/rGO nanoparticle was used as the electro-catalyst for the ethylene glycol (EG) oxidation reaction in the alkaline medium. The activity of Pd-Co/rGO was evaluated in the half-cell by cyclic voltammetry (CV) technique. Results demonstrate that Pd-Co/rGO electro-catalyst has higher performance compared to simple alloyed-based Pd electro-catalysts for EG electro-oxidation in alkaline media. Pd-Co/rGO catalyst showed well-defined peaks for the EG oxidation reaction after 150 CV cycle. This result indicated that Pd-Co/rGO electro-catalyst is still active in EG oxidation reaction even after 150 CV cycles, suggesting high poisoning toleration of Pd-Co/rGO electro-catalyst in the EG oxidation reaction. The results of electrochemical experiments indicated that Pd-Co/rGO could be practically used as the high-efficiency anode electro-catalyst for the EG oxidation reaction in alkaline media.

In the present work, a computer-based method is proposed to investigate the relationship between the steady-state grain size (ds) and stacking fault energy (SFE) in severely plastic deformed (SPDed) materials. The stacking fault energy, γ, plays an important role in determining the mechanical properties of face-centered cubic (fcc) metals. A number of models have been proposed to show this role. These models have several shortcomings, including complex computational variables, data constraints and small computational range constraints. The present model compatible with experimental results does not employ hard calculable variables. Besides, it is applicable not only for pure metals but also for alloys. The squared regression (R2) and error sum of squares (SSE) for the training and testing data of the presented model are 0.93, 0.0006 and 0.98, 0.00018, respectively, which indicates the high accuracy of the proposed model. The slope of the  versus  is about 0.6453 which is comparable to all the models offered in this field.

In this study, aluminum chips were milled in a planetary ball mill at different times and ball-to-powder weight ratios (BPRs). The resulting optimum powder was reinforced with 1 wt% and 2 wt% of multi-walled carbon nanotubes (MWCNTs). The effects of alloying time, BPR, and MWCNTs percentage on the morphology, distribution, and composition of the Al7075-MWCNT powder were investigated. The results showed that smaller particles with a limited size distribution can be obtainable by increasing BPR and decreasing mechanical milling time. A uniform dispersion of reinforcement (2 wt%) was achieved at lower alloying times (15 and 30 min) and a higher BPR (20:1). Using XRD analysis, it was revealed that the carbon peaks are more clearly in 2%-MWCNT powders than 1%-MWCNT ones. The addition of MWCNTs led to reducing the particle size; this is confirmed by the data obtained from the XRD patterns and their analysis with the Williamson-Hall model. Machining chips were converted into composite powder by cost-effective mechanical milling and alloying method with a uniform distribution of MWCNTs, which is unique.