Plating Process Research Articles

Investigations of the Interface Design of Polyetheretherketone Filament Yarn Considering Plasma Torch Treatment

Taking advantage of its high-temperature resistance and elongation properties, conductive-coated polyetheretherketone (PEEK) filament yarn can be used as a textile-based electroconductive functional element, in particular as a strain sensor. This study describes the development of electrical conductivity on an inert PEEK filament surface by the deposition of metallic nickel (Ni) layers via an electroless galvanic plating process. To enhance the adhesion properties of the nickel layer, both PEEK multifilament and monofilament yarn surfaces were metalized by plasma torch pretreatment, followed by nickel plating. Electrical characterizations indicate the potential of nickel-coated PEEK for structural monitoring in textile-reinforced composites. In addition, surface energy measurements before and after plasma torch pretreatment, surface morphology, nickel layer thickness, chemical structure changes, and mechanical properties were analyzed and compared with untreated PEEK. The thickness of the Ni layer was measured and showed an average thickness of 1.25 µm for the multifilament yarn and 3.36 µm for the monofilament yarn. FTIR analysis confirmed the presence of new functional groups on the PEEK surface after plasma torch pretreatment, indicating a successful modification of the surface chemistry. Mechanical testing showed an increase in tensile strength after plasma torch pretreatment but a decrease after nickel plating. In conclusion, this study successfully developed conductive PEEK yarns through plasma torch pretreatment and nickel plating.

Investigation of roll forming process and quality control factors for metal bipolar plates

Metal bipolar plates (BPPs) are crucial components of proton exchange membrane fuel cells (PEMFCs), with the quality of their formation affects the power generation efficiency and lifespan of the fuel cells. The predominant manufacturing method, stamping, often results in localized excessive stretching of metal BPPs, thereby limiting the depth of the flow channels. Roll forming, dominated by bending deformation, is a forming process that ensures uniform thinning and greater depth of BPPs. The multi-directional flow channel roll forming model for BPPs is constructed in this paper for the first time, the characteristics of the roll forming process is investigated. Effects of process parameters on the forming results are discussed. The investigation indicates that during the roll forming process, the channel ports and corners are critical areas where defects are most likely to occur. The average filling ratio of the longitudinal flow channels is 5.6% higher than that of the transverse flow channels. The plastic strain in the longitudinal flow channels is about 36% higher than in the transverse ones, which making the form is more difficult to form, but the thickness is more uniform. Increasing the diameter of the rollers can enhance the filling ratio and flatness, but it will exacerbate thinning at the corners of the flow channels. When the ratio of the flow channel width to the rib width is close to 1, the filling ratio of the BPP is higher, with less thinning, resulting in a better forming result. As the depth of the flow channel increases, resulting in a thinner BPP, when depth-to-width ratio exceeding 0.6 is more likely to lead to failure. Increasing the speed of roll forming can lead to a greater thinning of the BPP and may even cause it to crack. The thinner the sheet metal is, the higher the filling ratio of the BPP and the more uniform its thickness. Those results can provide technical references for the structural design and forming process optimization of BPPs.

Study on Springback Behavior in Hydroforming of Micro Channels for a Metal Bipolar Plate.

Bipolar plates are one of the most important components of proton exchange membrane fuel cells. With the miniaturization of bipolar plate flow channel sizes and the increasing demand for precision, springback has become a key focus of research in the bipolar plate forming process. In this paper, the hydroforming process for 316L stainless steel bipolar plates was studied, and an FEM model was built to examine the stress and strain at various locations on the longitudinal section of the plate. Modeling accuracy was validated by the comparison of experimental profile and thickness distribution. The effects of forming pressure and grain size on springback behavior are discussed. The results show that with increasing forming pressure, the springback value decreases initially, followed by an increase, but then again decreases. When the forming pressure is 80 MPa-100 MPa, the deformation of the lower element of the upper rounded corner is not uniform with more elastic regions, and the springback is positively correlated with forming pressure. The springback distribution pattern on the cross-section of the bipolar plate changes from a normal distribution to a distribution of "M" shape with increased pressure. The larger the grain size, the lower the yield strength elastic proportion, resulting in a decrease in springback of the sheet. The maximum amount of springback of the bipolar plate is 3.1 μm when the grain size is 60.7 μm. The research results provide a reference for improving the forming quality of metal bipolar plates with different flow channel shapes.

Numerical simulation of gas tungsten arc welding for ZW61 magnesium alloy thin plates

Mg-Zn-Y alloy has become the favorite of magnesium alloy research due to its excellent comprehensive performance and increasingly mature deformation process. For the gas tungsten arc welding (GTAW) process of ZW61 magnesium alloy thin plates, the physical field and microstructure evolution is simulated with the finite volume method and the cellular automata (CA) method in this paper. The flow field results show that the Marangoni force dominates the flow of liquid metal in the molten pool from the center of the molten pool to the edge of the molten pool. The increase in welding speed significantly increases the temperature gradient in the molten pool. In addition, from the results of the stress field, the residual stresses are mainly distributed in the fusion zone (FZ) and heat-affected zone (HAZ). The maximum longitudinal residual stress occurs in the HAZ, about 82 MPa. While the maximum transverse residual stress occurs at the end of the plate, about 104 MPa. Neither exceeds the tensile strength of ZW61 alloy, so no cracks appear in the joint. The temperature gradient of the welded plate and the solidification rate of the molten metal in the molten pool are regulated by adjusting the welding process parameters, to improve the microstructure in the FZ. The minimum average grain size of the FZ is only 29.50 μm under the optimum welding process conditions set in this paper.

Study of atomic diffusion behavior in diffusion welding of NiTi alloy - based on molecular dynamics

NiTi alloy with nearly equiatomic ratios of Ni and Ti, has a unique shape memory effect and biocompatibility. Atomic diffusion is a determinant factor for the diffusion welding of NiTi alloys joining. In general, the atomic diffusion may be mediated by the temperature, time and pressure and so on. Despite the importance of technology, Ni and Ti atoms’ diffusion mechanism, however, still remains un-elucidated. Few works have investigated the movement rules of atoms from the atomic scale. Molecular dynamics simulations of diffusion welding were performed for 200-800ps to investigate the diffusion process of the NiTi alloy composite plate at temperatures of 1000, 1100, 1200, and 1300K. The results show that the holding temperature had the greatest effect on diffusion, with pressure having the least effect. The diffusion coefficients of NiTi, Ni, and Ti were calculated at temperatures of 1000, 1100, 1200, and 1300K, respectively. The diffusion degree of Ni atoms was higher than that of Ti atoms. The diffusion coefficients of Ni and Ti atoms satisfied the Arrhenius equation, and the diffusion activation energy of Ni atoms was lower than that of Ti atoms. Furthermore, this study demonstrates at the atomic scale that the growth of the diffusion layer at high temperatures follows the parabolic growth kinetics law.

Analytical and Finite Element Analysis of the Rolling Force for the Three-Roller Cylindrical Bending Process.

In the roll bending process, the rolling force acting on the roller shafts is one of the most important parameters since, on the one hand, it determines the process settings including the pre-loading, and, on the other hand, its distribution and size may affect the integrity of both the bending system and the final product. In this study, the three-roller bending process was modeled using a two-dimensional plane-strain finite element method, and the rolling force was determined as a function of plate thickness, upper roller diameter, and yield strength for various API steel grades. Based on the numerical simulation results, a critical bending angle of 41° was identified and the rolling systems were divided into two categories, of less than or equal to, and greater than 41°, and an analytical model for predicting the maximum rolling force was developed for each category. To determine the optimal pre-tensioning force, two optimization formulations were proposed by minimizing the maximum equivalent stress and the absolute maximum displacement. The rolling forces predicted by the analytical models were found to be in good agreement with the numerical simulation results, with relative errors generally less than 10%. The predictive analytical models developed in this study capture well the complex deformation behavior that occurs during the roll bending process of steel plates, providing guidelines and predictions for industrial applications of this process.

Effect of Material and Structure of Ultra-High-Molecular-Weight Polyethylene Body Armor on Ballistic Limit Velocity: Numerical Simulation.

The material properties and structural characteristics of ballistic composites are crucial to their ballistic performance. A numerical model of a 1.1 g FSP penetrating a UHMWPE target plate was established in this paper. The numerical results show that the failure process of the body armor target plate primarily involves shear failure, interlayer delamination, and tensile failure. Based on this, further research was conducted on the influence of material properties and structural characteristics on the ballistic limit velocity of the UHMWPE armor plate. Furthermore, the study evaluates the effects of elastic modulus, tensile strength, shear strength, number of layers, and interlayer strength on the ballistic limit velocity of UHMWPE body armor. The findings reveal that the ballistic limit velocity is most sensitive to changes in shear strength, with variation rates ranging from -18% to +11%, showing an approximate positive correlation, while the elastic modulus has the smallest impact on ballistic limit velocity, with variation rates ranging from -2% to +4%. Additionally, appropriate interlayer strength can improve the ballistic limit velocity of the body armor to a certain extent. This study provides theoretical methods and recommendations for optimizing anti-penetration performance of UHMWPE body armor.

Synthesis, structure characterization, and corrosion properties of duplex electroless Ni-P/Ni-B and Ni-P/Ni-B-W coatings on mild steel

This study investigates the formation of duplex electroless Ni-P/Ni-B and Ni-P/Ni-B-W alloys through electroless plating process coatings on mild steel using hypophosphite and sodium borohydride as a reducing agent, employing heat-treated. Electroless plating is affordable and suitable for coating convoluted structures. Duplex electroless on mild steel was characterized by X-ray diffraction (XRD), Energy-dispersive X-ray spectrometry (EDS), scanning electron microscopy (SEM) were used to examine the surface and cross-sectional morphologies of the duplex coating, and finally study electrochemical corrosion properties. The analysis reveals that duplex coating yields a thicker, more homogeneous coating with a characteristic cauliflower morphology and spherical nodular structures. The coating was initially amorphous, but finally crystallized when heated to 400 °C. More corrosion resistance was found in the Ni-P/Ni-B and Ni-P/Ni-B-W layers when Ni-B served as the outer covering. This study focuses on the important effects of varying tungsten concentrations and heat treatment on the corrosion resistance, surface quality, and microstructural characteristics of duplex coatings. Showed improved corrosion resistance when exposed to 0.5 g/L of Na2WO4.

Minimum quantity lubrication grinding process for high aluminum-silicon glass mobile phone cover plates

Purpose The impact on both the environment and operator health is significant. As high-alumina silica glass finds applications in smart devices such as curved mobile phone screens, the grinding of complex curved surfaces necessitates cleaner and more efficient cooling and lubrication methods to enhance processing quality and improve grinding yield rates. This study aims to focus on grinding high-alumina silica glass using micro-lubrication technology and compares its performance with traditional cutting fluid cooling methods. Design/methodology/approach In the fabrication of mobile phone cover plates composed of high-alumina silicon glass, the incorporation of micro-lubrication grinding technology was undertaken, with the conventional cutting fluid cooling approach serving as the benchmark control group for comparative analysis. Findings The results indicate that increasing the spray pressure of micro-lubrication within a specific range contributes to reducing grinding surface roughness. At a grinding speed ranging from 25 to 35 m/s, using micro-lubrication can effectively replace the traditional cutting fluid cooling method, resulting in glass surfaces with roughness levels between 0.22 and 0.26. However, at grinding speeds exceeding 35 m/s, the insufficient pressure of the micro-lubricant mist hinders most of the oil mist from entering the grinding zone, leading to inferior cooling performance compared to cutting fluid cooling. Notably, at a grinding speed of 35 m/s, micro-lubrication demonstrates better effectiveness in suppressing chipping during glass grinding compared to traditional cutting fluid cooling methods. Originality/value Through the application of micro-lubrication grinding technology, a marked improvement in the grinding quality of high-alumina silicon mobile phone cover plate glass can be achieved, leading to a reduction in surface roughness, a decrease in processing defects and ultimately satisfying the demands for high-precision and high-quality fabrication of such cover plates. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2024-0297

Parameter Optimization for Laser Peen Forming on 6005A-T6 Aluminum Alloy Plates to Enhance the Constrained Deformation of Integral Stiffened Plates.

Multiscale parameter optimization for laser peen forming (LPF) on 6005A-T6 aluminum alloy plates was conducted through a combination of simulation and experimentation. By obtaining the optimal parameter, this study aims to explore the constrained deformation and forming laws of the integral stiffened plates. Detailed descriptions were provided regarding the dynamic response process and transient behavior of aluminum alloy plates under ultrahigh strain rates, along with an in-depth analysis of the stress evolution. The results reveal that laser beam diameter and laser beam energy can achieve large range forming, while the number of tracks facilitates the precise deformation adjustment. During the 12-track LPF process, there is an overall upward trend in deformation values accompanied by a dynamic increase in the bend curvature. After static relaxation, the deformation value recovers to 55.2% of the final bending curvature. The chord direction scanning of stiffened plates exhibits a larger bending curvature, indicating its greater forming capacity for large-sized single unfolding direction formation; whereas, the unfolding direction scanning of stiffened plates excels in achieving efficient integrated two-way forming.

Complexion-induced Cu2+ coordinated phase separation PBI membrane for lithium metal batteries

The uncontrolled dendritic lithium production issues and the highly reactive behavior of lithium with electrolytes has limited use of lithium metal batteries. Herein, we utilized a straightforward method of the Complexion-Induced Phase Separation (CIPS) to fabricate a Cu2+ coordinated polybenzimidazole (PBI) membrane for a lithium metal battery. CIPS offer improved control over the structure and composition of the membrane, potentially leading to improved selectivity in ion transport, enhancing the safety and longevity of the battery. The formation mechanism and influencing elements of PBI-Cu are analyzed through experimental analysis and density functional theory calculations (DFT). The PBI-Cu membrane is effective in facilitating reversible lithium stripping and plating processes, suppressing dendrite formation, and promoting stable long-term cycling. Notably, the PBI-Cu cell demonstrated stable cycling conditions for over 200 h at a very high current density of 4 mA cm−2. The impressive rate performance was also confirmed during Li//LiFePO4 full cell operation, where it maintained a stable capacity of 120 mAh g−1 for more than 300 cycles. This research provides an in-depth insight into membrane design and paves the way for its application in various other energy-related technologies.

A novel strategy for activation technique for 6H-SiC substrates in electroless Ni-P plating processes

This study proposes a novel iron wire activation method for electroless Ni-P plating on 6H-SiC substrates, offering a sustainable alternative to traditional metal activation techniques, focusing on the surface roughness effect on the microhardness and Ni-P plating efficiency of 6H-SiC substrates. This experimental approach reveals insights into the relationship between substrate morphology and plating characteristics. It is found that the plating thickness (33.82 μm) of the non-polished substrates closely matched the expected (33.26 μm), with a deposition rate of 6.65 μm/h, which underscores the precision regulation of the plating process. In contrast, despite the faster deposition rate of 9.20 μm/h of the polished S500 substrate, it exhibited a minor thickness discrepancy, suggesting a saturation point in the deposition dynamics on fully polished surfaces. The research additionally sheds light on the adhesion characteristics of the plated layers, particularly emphasizing the role of surface roughness. Remarkably, non-polished substrates demonstrated better adhesion, categorized as HF3, indicating a significantly stronger bond compared to the polished substrates, which were categorized as HF4 to HF6. This distinction in adhesion categories underlines the critical influence of substrate morphology on the quality of the Ni-P layer's adherence.

T2-weighted spoiled gradient echo MRI for forensic age estimation: a study on knee growth plates.

The timing of growth plate fusion is a key indicator for age estimation and is primarily used in forensic investigations. On the other hand, non-ionizing techniques such as MRI are being developed to provide safer and more ethical evaluations in forensic casework. This study aims to evaluate the closure process of growth plates in the distal femoral and proximal tibial epiphyses using Multiple Echo Recombined Gradient Echo (MERGE) MRI sequences and provide age estimation data based on staging methods for forensic purposes. We retrospectively analyzed 559 patients (294 males, 265 females, aged 8-25 years) diagnosed with trauma and knee pain at Tepecik Training and Research Hospital from 2016 to 2019. MRI scans were performed using a 1.5-T system with MERGE sequences and evaluated by two observers using a new staging system. Observer agreement was assessed using Cohen's κ test, yielding high agreement values (κ > 0.8). Positive correlations were found between age and ossification stages (p < 0.001). Minimum age thresholds for stages 5a and 5b of the distal femoral epiphysis were 16 and 18 years for females and 17 and 19 years for males, respectively. For the proximal tibial epiphysis, the minimum ages for stages 5a and 5b were 15 years for females and 17 years for males. The MERGE sequence provides a viable method for assessing skeletal maturity in living individuals with significant ethical advantages due to non-ionizing radiation. This study supports the potential application of the MERGE sequence in forensic age estimation, demonstrating high observer agreement and consistency. Future research should focus on comparing different sequences and populations to enhance the methodology's applicability.

Corrosion-resistant titanium-based electrodes synergistically stabilized with polymer for hydrogen evolution reaction

The economic and reasonable design of highly stable and corrosion-resistant electrodes is fundamental to achieving the industrial-scale hydrogen productions via water electrolysis, but electrodes’ premature failures are often caused by corrosion and stress damage. Therefore, these challenges are successfully solved by utilizing conductive and crack-resistant polyaniline “stabilizer” with a mild chemical plating process to construct the catalytic electrode on a titanium substrate (15 %PANI-NiB@Ti) in the present work. The 15 %PANI-NiB@Ti catalytic electrodes have been in continuous operation for 350 h at the current density of 200 mA cm−2 with the high efficiency of 98.4 % in a 323.15 K environment. With the high economy and universality, the catalytic electrodes have good catalytic performance and reliability in the extreme industrial environments, such as high temperature, air, and high current density. Except for the above advantages, the 15 %PANI-NiB@Ti catalytic electrodes also have good cracking resistance, which provides a novel and feasible approach to the industrial application of transition metal catalytic electrodes.

Research Status of Laser Welding Technology for Thin Metal Plates

Thin metal sheets have always been one of the core materials in the mechanical industry, and laser welding technology is an important technique for connecting thin metal sheets. This article analyzes the current research status of laser welding technology for metal thin plates, discusses the problems existing in laser welding technology for metal thin plates, points out the development direction of laser welding technology for metal thin plates, solves some problems in the welding process of metal thin plates, and provides reference for future thin plate welding technology.

Laser Cutting of Titanium Alloy Plates: A Review of Processing, Microstructure, and Mechanical Properties

The growing use of titanium alloys has led to the gradual replacement of traditional processing methods by laser cutting technology, making it the preferred method for processing titanium alloy plates due to its high efficiency, precision, and adaptability. In this review, the characteristics of laser cutting technology and its application in titanium alloy plate processing are summarized, outlining several aspects of the cutting process, microstructure, and mechanical properties of the material after cutting, along with simulation predictions. Previous research categorized laser-cutting input parameters into beam parameters and process parameters, with the commonly used parameters being the laser power, cutting speed, and gas pressure. Various parameter combinations can achieve different cutting qualities, and seven indices can be used to evaluate the cutting process, with the surface roughness and slit width serving as the most common indices. Different auxiliary gases have shown a significant impact on the laser cutting quality, with commonly used gases consisting of nitrogen, argon, and air. Argon-assisted cutting generally results in better surface quality. Due to the rapid temperature change, the titanium alloy microstructure will undergo a non-diffusive martensitic phase transformation during laser cutting, producing a heat-affected zone. Experimental studies and simulations of the mechanical properties have shown that the occurrence of a martensitic phase transformation increases the hardness and residual tensile stress of the material, which reduces the fatigue strength and static tensile properties. In addition, studies have found that the more streaks appear on the cut surface, the lower the fatigue strength is, with fatigue cracks arising from the stripes. Hence, the established analytical solution model and three-dimensional finite element model can effectively predict the temperature distribution and residual stress during the cutting process. This can provide a better understanding of the high residual stress characteristics of the cutting edge and the stripe formation mechanism, allowing researchers to better explore the mechanism of laser cutting.

Analysis of Thickness Variation in 2219 Aluminum Alloy Ellipsoid Shell with Differential Thickness by Hydroforming

The process of spinning and machining for heavy plates has the problems of a large amount of machining, large springback, and easy cracking. Aiming to address these issues, we proposed a deep drawing forming method for a plate with differential thickness to manufacture an integral ellipsoid component with a thin zone in the middle and a thick zone in the periphery. The plate with a differential thickness was initially produced through machining, followed by the execution of deep drawing deformation. During the deformation process of plates with differential thickness, the thin zone is prone to rupture defects. Therefore, a hydroforming method utilizing an elastic auxiliary plate was adopted to solve this problem. Through mechanical analysis and deep drawing experiments, the influences of hydraulic pressure and elastic auxiliary plate on the distributions of thickness and strain were studied, and the influence of friction on hydroforming was analyzed. The results indicate that increasing the hydraulic pressure and setting elastic auxiliary plates can increase the interfacial friction, reduce the thickness thinning rate, and improve the thickness distribution and deformation uniformity within the thin zone. When the hydraulic pressure is 5.2 MPa and the thickness of the elastic plate is 5 mm, the maximum thickness thinning rate of the ellipsoid shell is 8.8%, which is 34% lower than that of the ellipsoid shell obtained via conventional deep drawing.

Study on the forging process of artificial bone plates of SUS 316L

Abstract SUS 316L stainless steel, valued for its strength and biocompatibility, is a popular choice for artificial bone plates. Forged SUS 316L plates offer advantages like enhanced strength, improved fatigue resistance, reduced material waste, and increased production efficiency. Consequently, the forging technology and die design for SUS 316L is crucial in the manufacturing of high quality artificial bone plates. Finite element analysis simulates the forging process of SUS 316L bone plates, guiding the selection of the appropriate forging machine, die design, and process parameters based on the resulting forging load, stress distribution, and filling condition. Ultimately, this approach facilitates the creation of high-quality SUS 316L bone plates with precise dimensional accuracy.

Evaluating copper plating process for filling micro vias with thin surface Cu by the 1-(4-carboxyphenyl)-5-mercapto-1H-tetrazole additive

The 1-(4-carboxyphenyl)-5-mercapto-1 h-tetrazole (CMHT) as a novel leveler for the overfilling of micro-blind vias was investigated in acidic copper electroplating. The synergistic effect between CMHT and other additives were confirmed through chronoamperometry, cyclic voltammetry and electrochemical impedance spectroscopy. The results showed a convection-dependent interaction between the CMHT and suppressor (propyleneoxide (PO)-ethylene oxide (EO)-propylene oxide (PO), named PEP). Metallographic section testing demonstrated that the CMHT not only have excellent microvia filling performances, but also only have 19.1 μm thin surface Cu for micro blind vias with a diameter of 150 µm and a depth of 80 µm by the electrodepositing 60 min of 2 A/dm2. The quantum chemical calculations experiments revealed also that the CMHT parallel orientation of the benzene ring and tetrazole heterocycle can enhance the effective adsorption area. The obtained results from electrochemical test and quantum chemical calculations were in reasonably good agreement.

Re-understanding and mitigating hydrogen release chemistry toward reversible aqueous zinc metal batteries

Interfacial H2 release severely limits the reversibility and feasibility of aqueous Zn metal batteries for large-scale energy storage. Different from the conventional perception that H2 release mainly originates from the competition between hydrogen evolution reaction and Zn plating process, we herein surprisingly find that non-negligible H2 is also generated during stripping due to the accelerated chemical corrosion of the newly exposed Zn surface. To address this issue, we systematically screened the organic additives with different molecular structures and functional groups. Interestingly, a positive correlation between the adsorption strength of additives and the ability to inhibit the interfacial hydrogen release is found. Taking cysteamine (MEA) as a model additive, a gradient solid electrolyte interphase (SEI) is in situ formed at the Zn surface, acting as a chemical “barrier” to isolate interfacial water molecules from electrode surface consequently enable a higher Coulombic efficiency (>99.5%, 4000 cycles) compared with that of MEA-free electrolyte (98.1%, 189 cycles). This work provides a new understanding of the interfacial hydrogen release mechanism and the criteria for selecting additives for aqueous Zn metal anodes.