Seyed Reza Elmi Hosseini, Fatemeh Azarnia, Hassan Saghafiana, Javad Behzadifara,
Volume 23, Issue 3 (9-2026)
Abstract
In this study, the feasibility of laser welding on anodized aluminum alloy has been investigated. There are many demands in the industry for the welding of anodized aluminium sheets. Firstly, the anodizing process was performed by changing the anodizing time and keeping the other anodizing parameters constant. The anodizing process was performed at three different anodizing times of 30, 45, and 60 minutes. Then, the sample with the largest oxide layer thickness, which was obtained at the higher anodizing time, was chosen for the laser welding. The welding process was performed at a laser power of 1500 watts and a welding speed of 300 mm/s on an anodized 6061-T6 aluminum alloy with an oxide layer thickness of 17 microns. The current investigation depicted that the sound joint occurred between two anodized aluminium sheets. Although the anodized layer acts as an inhibitor for the joining of aluminum sheets due to its high melting point, the results showed a homogeneous distribution of the elements within the weld zone. In the meantime, the growth of dendrites across the weldment shows the concentration of elements in the interdendritic regions of the weldment.
Shayan Sarraf, Seyedeh Marzieh Hosseini, Saeed Rastegari, Mansour Soltanieh,
Volume 23, Issue 3 (9-2026)
Abstract
In this study, Ni-Co-CeO2 nanocomposite coatings were deposited on copper substrates via a sol-enhanced electrodeposition method. Cerium oxide nanoparticles were synthesized using cerium chloride precursor and HMTA as a precipitating agent at 70 °C and subsequently added to a Watts bath containing nickel and cobalt ions. An investigation of the effect of deposition current density (10 to 30 mA.cm-2) revealed that increasing the deposition current density reduced the cerium oxide content in the coating from 12.2 to 7.1 wt%. SEM images confirmed a morphological transformation from an acicular structure to a fine-grained microstructure with surface heterogeneity in the presence of the nanoparticles. XRD results further demonstrated grain refinement induced by the CeO2 reinforcing phase. Electrochemical evaluations in 1 M KOH solution showed that the sample deposited at a current density of 20 mA.cm-2 exhibited the highest performance, with a discharge time of 92 seconds (a 77% improvement compared to the particle-free sample) and optimal charge transfer resistance. This enhanced performance is attributed to a favorable balance between the electrical conductivity of the metallic matrix and the catalytic activity of the cerium oxide nanoparticles. The findings of this investigation substantiate the efficacy of the sol-enhanced method in designing advanced electrodes for energy systems.
Krishnakumar K, Rajamanickam M.r,
Volume 23, Issue 3 (9-2026)
Abstract
Track rollers used in bucket wheel excavators are subjected to repeated mechanical loading in an environment where abrasive particles, moisture and corrosive contaminants can accelerate surface deterioration. The present study examines the mechanical, electrochemical and tribological behaviour of GS‑42CrMo4V cast steel used for this application. The material w::as char::acterized through chemical composition analysis, microhardness measurement, tensile testing and fractographic examination. Its corrosion behaviour was further evaluated in 3.5 wt.% NaCl and acidic HCl and H₂SO₄ solutions using potentiodynamic polarization and electrochemical impedance spectroscopy, while three-body abrasion and reciprocating wear tests were carried out to assess its resistance to material loss under different contact conditions. The bottom roller exhibited an average microhardness of 430 HV, compared with 314.2 HV for the roller pin. Tensile and fractographic observations indicated good mechanical performance, although localized damage features were observed on the fractured surfaces. The electrochemical results showed that the material performed better in the neutral chloride solution than in the acidic media. In 3.5 wt.% NaCl, the corrosion current density and corrosion rate were 1.597 μA cm⁻² and 0.487 mpy, respectively, whereas the acidic solutions produced considerably higher corrosion activity. The wear tests confirmed that high hardness alone did not prevent material removal under abrasive and sliding contact. Abrasive action, plastic deformation and localized adhesive interactions contributed to surface degradation under the investigated conditions. The results therefore indicate that, despite its favourable hardness and mechanical characteristics, GS-42CrMo4V remains susceptible to degradation in aggressive acidic environments and under severe abrasive and sliding conditions. The observed behaviour points to the need for further improvement in material processing, surface condition, corrosion protection and the control of abrasive particle ingress. These findings provide a basis for understanding the service-related limitations of the material and for improving the durability of track rollers used in mining equipment.
