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Copper (Cu) is widely used as electrical conducting and contacting material. However, Cu is soft and does not have good mechanical properties. In order to improve the hardness and wear resistance of Cu, sol-enhanced Cu–Al₂O₃ nanocomposite coatings were electroplated by adding a transparent Al oxide (Al₂O₃) sol into the traditional electroplating Cu solution. It was found that the microstructure and mechanical properties of the nanocomposite coatings were largely influenced by the Al₂O₃ sol concentration. The results show that the Al₂O₃ nanoparticle reinforced the composite coatings, resulting in significantly improved hardness and wear resistance in comparison with the pure Cu coatings. The coating prepared at the sol concentration of 3.93 mol/L had the best microhardness and wear resistance. The microhardness has been improved by ~20% from 145.5 HV (Vickers hardness number) of pure Cu coating to 173.3 HV of Cu–Al₂O₃ composite coatings. The wear resistance was also improved by ~84%, with the wear volume loss dropped from 3.2 × 10^-3 mm³ of Cu coating to 0.52 × 10^-3 mm³ of composite coatings. Adding excessive sol to the electrolyte deteriorated the properties.

The microstructure, microhardness and wear property of electroplated Ni–ZrO₂ nanocomposite coatings with different ZrO₂ concentration were analyzed using SEM, microhardness and wear tests. It was found that in the composite coatings, incorporation of ZrO₂ particles improves the mechanical property of Ni coatings and the effect of ZrO₂ nanoparticles concentration on the surface morphology, microstructure and mechanical property of electroplated coatings was discussed. The mechanical properties of Ni–ZrO₂ coatings reach the optimum value when the ZrO₂ concentration is 10 g/L.

This study has analyzed the welding joint of carbon fiber reinforced plastics (CFRP) and aluminum alloys. The surface of CFRP and 5083 Al alloy was modified by electroplating with nickel at first. Then the effect of electroplating parameters on coating was explored. SEM images revealed that the coating gradually became well but then began to fall off with the current density and the plating time increased. CFRP and aluminum alloys were brazed at 285${}^{\circ }$C and held for 20 s. Shear test was used to evaluate the strength of the joint and the strength was probably 7.56 MPa. SEM and EDS tests showed that there existed diffusion of the elements in the welding process and the joint reached the bonding of atomic or molecular sizes. Thus, this experiment achieved the tight brazing joining between thermoset CFRP and aluminum alloys providing the joining method of the application for CFRP.

In this paper, the Ni–Fe–P–TiO₂ coatings with different TiO₂ sol addition have been prepared by a sol-enhanced electroplating process. The microstructures and elemental compositions of prepared coatings were systematically characterized. The coating performance including mechanical properties and corrosion resistance were investigated. The results show that the proper addition of 10 mL/L TiO₂ sol slightly refines the surface morphology, while a much higher 50 mL/L TiO₂ sol addition causes a relatively nonuniform surface. The much-improved mechanical and corrosion performance is achieved by adding 10 mL/L TiO₂ sol, due to the strengthening effect by the well-dispersed nanoparticles and the compact, uniform surface structure. The wear tests confirm that abrasive wear dominates in the sample modified by 10 mL/L TiO₂ sol, while adhesion is the primary type for other samples.

As the key components of grating-based X-ray phase contrast imaging, absorption gratings are essential to be fabricated. In fact, the internal stress is one of the critical issues for the application of the electroplated gold deposit as the absorption metal for absorption gratings. It is common that high internal stress levels can cause the deposit cracking, blistering and peeling away from the substrate material. This study investigates the effect of current density on the internal stress by the bent strip method. The surface morphologies of gold deposits are examined using scanning electron microscopy (SEM) and the crystal structure of the electroplated deposit is analyzed by X-ray diffraction (XRD). The change of current density reverses the internal stress of the deposits from compressive to tensile. The value of deposit stress can be near zero by optimizing the current density.

SiC-mixed Sn–58Bi composite solder bumps were successfully fabricated via an electroplating process. For the composite solder bump fabrication, ultrasonically dispersed SiC nanoparticles were added to the plating solutions. DSC analysis indicated that the melting temperature of SiC-mixed Sn–58Bi solders was the same as that of the non-mixed Sn–58Bi. Shear strengths of Sn–58Bi+SiC solder bumps were 6% higher than that of non-mixed solder bumps. The thicknesses of intermetallic compound were almost the same for both Sn–58Bi and Sn–58Bi+SiC samples. The Sn–58Bi+SiC composite solder bumps had finer lamellar structures than non-mixed Sn–58Bi. From the fracture surface analysis, fracture occurred at solder bump matrix, not at joint interface. Therefore, the addition of the SiC nanoparticles in the Sn–58Bi solders decreased the grain sizes, which increased the shear strengths.

In this work, calcium (Ca)-modified titanium dioxide (TiO₂) nanoparticulate (NP) films were successfully prepared using sparking off Ca-electroplated Ti tips. Aqueous solution of calcium carbonate (CaCO₃) was used as electrolyte in the electroplating process. The experiment was carried out using electric current of 0.02mA applied to titanium electrodes for 10min. The NP films with small and uniform size were deposited on quartz substrate using the sparking process with a high DC voltage of 4kV in ambient air. The as-deposited NP films were then annealed at 800^∘C, 900^∘C and 1000^∘C for 3h under atmospheric pressure to improve their crystallinity. Morphology, structural and optical properties of the NP films were characterized by SEM, XRD, Raman, XPS and UV-Vis spectroscopy. The effects of annealing temperature on the properties of the as-deposited and annealed NP films were reported. Furthermore, photocatalytic activity against 10 $\mu$M of methylene blue (MB) under visible light region will be discussed.

Although electroplated hard chromium coatings were extensively studied and applied in industry, the properties of the coatings after annealing at different temperatures were investigated insufficiently. In this work, the influence of heat treatment on the mechanical, tribological, and structural properties of chromium coating, electrochemically deposited on 38HN3MFA steel were investigated. A specific bath composition and deposition parameters were selected, which has been compared to the literature data. Parameter selections were based on data from military research industry and contain noticeably lower amount of sulfuric acid (1.2g/L), CrO₃ (180g/L) and lower current density (25A/dm${}^2)$. Coefficient of friction and coatings wear rate were measured by means of ball-on-disc method at the temperature of 30${}^{\circ }$C, 200${}^{\circ }$C, 500${}^{\circ }$C, and 700${}^{\circ }$C. The coefficient of friction has decreased from 0.71 for the temperature of 30${}^{\circ }$C to the value of 0.5 for 700${}^{\circ }$C due to the change of wear mechanism. Hardness of the as-received coating reaches the value of 11.4GPa and 9.5, 8.3, 6.4GPa for the samples after annealing in the temperature of 200${}^{\circ }$C, 500${}^{\circ }$C and 700${}^{\circ }$C, respectively. The influence of heat treatment on structural properties of electroplated Cr coatings was studied by X-ray diffraction. Scratch test showed that layer is characterized by excellent adhesion with no adhesive rupture. Cr-coated 38HN3MFA steel exhibits reduced susceptibility to high-temperature degradation by 25%, basing on the mass lost measured at 900${}^{\circ }$C.

Anticorrosion requirements for the metallurgy, automotive, and aeronautical industries have increased in recent years, for which alternative plating chemicals must be developed. This study focuses on obtaining a Zn-Ni alloy plating with higher corrosion resistance and brightness. For this purpose, tetraethylenepentaamine as complexing agent, triethanolamine as the surfactant, and gelatin and $p$-aminobenzenesulfonic acid as brightening agents for the plating were selected and their optimal concentrations were determined for applications. The optimal Zn-Ni ratio and plating thickness were analyzed using an X-ray Dal device. Improved plating performance of the Zn-Ni alloys was achieved with a Zn-Ni alloy containing 12–14% Ni.

This paper outlines a framework for flexible hoist scheduling that utilizes a knowledge-based simulation system to emulate multi-hoist operations in an electroplating line and derives hoist schedule to meet production demands. The selected hoist schedule is then used by the knowledge-based controller to control the material handling hoist operations in real-time. The paper describes the overall design of the knowledge-based simulator for material handling hoist operations that forms the fundamental part of the proposed framework. Most hoist schedules in industry are experimented on-line, which are costly and time consuming. The use of knowledge-based simulation will save both cost and time. The simulator aims at improving current manual approaches so that better schedules can be identified. We demonstrate the application of the simulator to bi-directional multi-hoist line configuration that is commonly found in industry today, where loading and unloading stations are on the same end of the line, and consider other more realistic system parameters than those considered in previous studies. Three new hoist scheduling heuristics are proposed and their performances are compared with four previously studied rules. To this end, we also study the effect of several system variables such as hoist speed and inter-hoist distance on productivity. The simulation models developed are based on data from actual multi-hoist electroplating lines within several PCB manufacturing facilities.

Customer requirements and specifications are becoming increasingly complex, resulting in more complicate production processes to meet these requirements. With this complexity come anomalies and deviations into processes. On the other hand, we are seeing a new generation of technology can handle complexity of process and discover unusual executions of large and complex processes by tracing their generated data and transforming it into insights and actions. Hence, using data in industry becomes inevitable, giving it a fundamental role in improving efficiency and effectiveness of any organization. However, it is not sufficient to store and analyze data, but also the ability to link it to operational processes and be able to pose right questions; moreover, a deep understanding of end-to-end processes, which may ultimately accelerate every aspect of detecting abnormal process executions and determining process parameters responsible for quality fluctuations. Anomaly detection in manufacturing has raised serious concerns. Any divergence in process may lead to a quality degradation in manufactured products, energy wastage and system unreliability. This paper proposes an approach for anomaly detection in electroplating processes by combining process steps ordering relationship and boosted decision tree classifiers, XGBoost system, that employs the dimensionality reduction using Kernel principal component analysis which turns out to be effective in handling nonlinear phenomena using the Gaussian kernel on a self-tuning procedure. This approach has ensured a good accuracy property while maintaining enough generalization characteristics to beat data size and complexity challenges in order to improve detection rate and accuracy. The approach was validated using a dataset representing electroplating executions in year 2021. The classified anomaly events produced by our approach can be used, for instance, as candidates for a generalized anomaly detection framework in electroplating.