Cu-Pd and Cu-Pd-Ag alloys can find application as corrosion-resistant conductors of weak electrical signals. The work is devoted to the comparison of the structure and physical and mechanical properties of copper, Cu-8Pd and Cu-8Pd-3Ag alloys (at %). Samples in various initial states were studied: quenched and deformed, and annealed at temperatures ranging from 150 to 450 degrees C. Heat treatment durations ranged from 0.5 to 216 h. It has been established that in almost the entire range of annealing temperatures, the electrical resistance of the ternary alloy is higher than that of the binary alloy. The most significant increase in electrical resistance of both the initially deformed and pre-hardened alloy Cu-8Pd-3Ag is observed after annealing for maximum duration at temperature of 250 degrees C. X-ray diffraction patterns of samples after such heat treatment remain virtually unchanged.
The addition of nano scale ceramic reinforcements into lightweight metal matrices has gained a large attention towards the development of advanced structural materials. In this research, the AZ91D magnesium alloy matrix was reinforced with nano-CeO2 particles to form a magnesium metal matrix composite that has enhanced mechanical and thermal properties. This fabricated composite is subjected to a Quantitative Phase analysis using X-Ray Diffraction (XRD) to identify and evaluate the crystalline phases and their relative volume fractions. Scanning Electron Microscopy (SEM) is used to describe the surface morphology of the reinforced matrix. The results show the formation of a highly crystalline Mg–CeO2 composite with nanoscale reinforcement, stable interfacial bonding and absence of secondary phases, highlighting the potential of nano CeO2 as an effective reinforcement for lightweight magnesium-based metal matrix composites.
This study investigates an efficient hydrometallurgical route for the recovery of Pb from spent Pb–acid battery paste using nitric acid leaching followed by carbonate precipitation. Effect of different inorganic and organic acid were investigated. It was observed that nitric acid exhibited highest recovery among other acids. Response Surface Methodology (RSM) was applied to optimize process based on a Box–Behnken design by evaluating the effects of acid concentration, particle size, and stirring time. A second-order polynomial model was developed, and analysis of variance confirmed the adequacy and significance of the model with a high coefficient of determination (R2 = 0.9795). Particle Size was identified as the most influential parameter. Under optimized conditions such as acid concentration 3.8134 M, particle size 150 μm and stirring time 210 min, a maximum recovery of Pb, approximately 91.21
The main objective of this part of the research is to address the insufficient improvements in mechanical and tribological properties resulting from powder metallurgical (PM) fabrication processes for metal matrix composites derived from A356 aluminum alloy. The aim of this study was to investigate the impact of successive incorporation levels (0.5–3.5 wt
In this paper, the effect of deformation by equal-channel angular pressing (ECAP) and subsequent coating formation using various regimes (pulsed unipolar polarization—PUP and pulsed bipolar polarization—PBP) of plasma electrolytic oxidation (PEO) on the corrosion behavior of a bioresorbable Mg–Zn–Zr magnesium alloy was studied. Structural studies, gravimetric and electrochemical corrosion tests were performed to evaluate the alloy’s resistance to corrosion in Ringer’s solution. It was found that the use of ECAP contributes to structure refinement and a decrease in the corrosion rate, as compared to the initial state, to 7.6 ± 0.7 mm/year. The best corrosion resistance of the alloy in both the initial and deformed states is ensured by applying the PEO coating using the PUP regime; the corrosion rate was 2.8 ± 0.2 and 3.8 ± 0.4 mm/year, respectively. This may be due to the fact that this regime exhibits a higher content of the high-temperature forsterite Mg2SiO4 phase. Electrochemical tests indicate a decrease in the corrosion current density for the PEO-coated samples by 3–4 orders of magnitude. ECAP processing leads to an increase in the polarization resistance to corrosion for the samples with a PEO coating produced in the PUP and PBP regimes.
