Electrochemical Workstation Research Articles

A Reliable, Practical and Cost-Effective Portable Wireless Potentiostat for Mobile Chemical Sensing and Biosensing

Abstract Traditional electrochemical workstations are costly, complex, bulky, and primarily used in laboratories. This study develops a reliable, practical, and cost-effective portable wireless potentiostat to achieve real-time detection on-site and overcome the limitations of traditional electrochemical workstations. The system employs a general-purpose microcontroller unit (MCU), a dual-mode Bluetooth module and cost-effective multi-analog-to-digital converter (multi-ADC) to achieve differential sampling of the LMP91000. The system is equipped with buttons and OLEDs, enabling connection to mobile phones and computers for in-depth data analysis or independent operation. The system was successfully tested with [Fe(CN)6]3-, C6H12O6, and C3H6O3 solutions at concentrations ranging from 0 to 20 mM. The goodness-of-fit (R²) values are 0.984, 0.996, and 0.998, respectively. The average relative standard deviation of the three blank solutions is approximately 3.22%. The detection limits measured (0.003, 0.009, and 0.005 mM) are all lower than the minimum detection concentration (0.2, 0.1, and 0.1 mM). The coefficient of variation for repetitive experiments is less than 5.53%. The device accurately executed chronoamperometry (applied voltage range is ± 1.2 V, current range is ± 882 μA, accuracy is ± 1 %) with high sensitivity and good repeatability. Based on this circuit, a lactic acid detector and a urine glucose detector were developed, which work stably and support long-term operation, proving the stability and reliability of the circuit. Compared to commercial electrochemical workstations, PWES offers remarkable advantages in cost (< $6.4), size (41.5 mm × 76.5 mm), and practicality, making it suitable for a range of applications, including biomedical analysis, food safety, environmental monitoring, and smart wearables.

An oriented self-assembly biosensor with built-in error-checking for precise midkine detection in cancer diagnosis and prognosis evaluation

Midkine (MDK) is a neurotrophic growth factor highly expressed during embryogenesis, currently recognized as a multifaceted factor in cancer progression and drug resistance. MDK has demonstrated greater accuracy than existing biomarkers. Serum MDK is a valuable indicator for the non-invasive early detection of tumors. It dynamically changes following surgical tumor excision and prior to recurrence, facilitating prognosis and treatment response evaluation. However, existing methods struggle to achieve the sensitivity required for clinical applications. Herein, we developed a triple-mode biosensor with oriented self-construction and built-in error-checking for rapid, sensitive, and convenient MDK detection. The sensor construction adhered to the principle of achieving oriented and strong covalent connections to ensure high sensitivity. Biosynthesized quantum dots (BQDs) were introduced to orient antibodies, enhancing the exploration of active binding sites and significantly increasing antibody-capturing ability. To further enhance sensitivity and signal amplification, Au@Pt nanorods-Ab2 (MF-Probe) were used as multifunctional probes, incorporating an error-checking mechanism to minimize false results. Detection was feasible using an electrochemical workstation, a microplate reader, and even a mobile phone. The sensor exhibited a wide linear range from 5 fg/mL to 100 ng/mL and a low limit of detection (LOD) of 1.620 fg/mL. It accurately distinguished MDK levels in the serum of healthy donors and cancer patients. Compared to existing ELISA kits, it exhibited a lower LOD and a more sensitive response to trace MDK, suggesting it is a promising tool for cancer diagnosis and prognostic evaluation.

Ce-Doped Iron Oxide Anticorrosive Coatings: Effect of c(Ce4+):c(Fe3+) Ratio on Structure, Morphology, and Coating Anticorrosion Performance

Utilizing hydrothermal methods, Ce-doped iron oxide nanoparticles were synthesized from precursor solutions under different c(Ce4:c(Fe3+) precursor solutions. The effects of the c(Ce4+):c(Fe3+) ratio in the precursor solutions on the nanoparticle morphology and nanoparticle structure of the Ce-doped iron oxide were investigated using X-Ray diffraction, transmission electron microscopy, and scanning electron microscopy. Fourier transform infrared spectroscopy (FTIR) was used to examine the bond energy strength of the Ce-doped iron oxide nanoparticles. The electrochemical properties of the Ce-doped iron oxide nanoparticles were tested using an electrochemical workstation and a saltwater immersion resistance test. The corrosion resistance of Ce-doped iron oxide coatings at different c(Ce4+):c(Fe3+) ratios was systematically analyzed, uncovering corrosion resistance mechanisms and self-healing capabilities. The results show that as the c(Ce4+):c(Fe3+) ratio decreases, the lattice constants of the samples increase along with the average grain size. Both smaller and larger c(Ce4+):c(Fe3+) ratios are detrimental to lattice distortion in α-Fe2O3. The reduced number of valence electrons provided by cerium ions in Ce-doped iron oxide hinders the generation of holes and exerts a minor influence on the crystal band structure, leading to weaker electrochemical stability. The Ce-doped iron oxide coating prepared at a c(Ce4+):c(Fe3+) ratio of 1:60 readily generates a higher number of reactive hydroxyl radicals during corrosion, thus exhibiting enhanced self-healing capabilities and corrosion resistance.

Redox Activity of Co Species in the Active Sites of CoNx/CoOx Facilitates Oxygen Electrocatalysis for Zn-Air Batteries.

Developing efficient bifunctional oxygen electrocatalysts is crucial for enhancing the performance of rechargeable Zn-air batteries (ZABs). In this study, cobalt/cobalt oxides embedded in N-doped carbon nanofibers (Co/CoOx/NCNFs) were synthesized through a combination of electrospinning and annealing processes. The resulting Co/CoOx/NCNFs catalysts feature abundant CoNx and CoOx active species, leveraging the large specific surface area of nanofibers to facilitate oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The optimized Co/CoOx/NCNFs-0.1 achieved a half-wave potential (vs. RHE) of 0.82 V and required only 429 mV to reach 10 mA cm-2 in a typical three-electrode system with 0.1 M KOH using an electrochemical workstation equipped with a pine instruments rotator, outperforming the Pt/C+RuO2. The assembled ZABs exhibited high specific capacity (771 mAh gZn -1), substantial power density (981.6 mWh gZn -1), and long-term stability (>325 h). In situ Raman spectroscopy confirmed that the electrocatalytic processes involve the redox activity of Co (II and III) species derived from abundant CoNx and CoOx, elaborating the origin of the catalysts' exceptional oxygen electrocatalysis performance. This work not only presents a straightforward and effective approach for producing bifunctional oxygen electrocatalysts in ZABs but also sheds light on the catalytic mechanisms underlying ORR and OER for CoNx/CoOx-based oxygen electrocatalysts.

Synergistic Effect of Polyurethane on Pore-Sealing and Lubrication of Microarc Oxidation Coating.

Microarc oxidation (MAO) is a widely used surface treatment technology. However, its processing inevitably leads to the presence of micropores, microcracks, and other defects in the MAO coating. These defects lead to suboptimal tribological performance and diminished corrosion resistance of the MAO coating. Thus, this study proposed a new pore-sealing method with environmental protection and high efficiency. Polyurethane reactive (PUR) composite coating was prepared on the surface of MAO coating. The sealing effect of the PUR sample was analyzed using scanning electron microscopy (SEM). The molecular structure and elemental changes of the coating were analyzed using X-ray photoelectron spectroscopy (XPS). The tribological properties were analyzed using a tribological testing machine, and the corrosion resistance was tested using an electrochemical workstation. The test results show that the lubricity and corrosion resistance of PUR sample are improved significantly compared with MAO coating. When the mass fraction of PUR is 3 wt %, the PUR sample shows the best lubrication performance, and the coefficient of friction decreases by 70.8%. Compared with the traditional sealing technology, this experimental method is simple and low-cost and has a wide application prospect, which promotes the development of MAO technology.

The Dependence of Electrochemical Behavior and Discharge Performance on the Zn/Gd Ratio of Mg-Li-Zn-Gd Anodes for Mg-Air Batteries

In this study, the electrochemical performance and discharge behavior of Mg-Li-Zn-Gd alloys with α-Mg and β-Li-based anode material are investigated, with the aim to improve the anode performance of Mg-air batteries. The experimental anode alloys with detailed Mg-8Li-xZn-yGd (x = 1, 2, 3; y = 1, 2, 3 wt.%) components are prepared, and extrusion deformation is carried out on these alloys. Simultaneously, scanning electron microscope (SEM), X-ray diffractometer (XRD), electrochemical workstation, and constant current discharge systems are applied for microstructure characterization, corrosion, and discharge performance testing. The results show that the experimental alloys are composed of an α-Mg and β-Li dual matrix, with W-Mg3Gd2Zn3, Mg3Gd, and MgLiZn second phases. Meanwhile, extrusion deformation promotes the recrystallization process through the particle-induced nucleation mechanism. The corrosion resistance is improved with the increasing Zn/Gd ratio, and the extruded Mg-8Li-2Zn-1Gd (LZG821) alloy exhibits the optimum corrosion resistance, with a corrosion rate of 0.493 mm·year−1. In addition, the extruded Mg-8Li-1Zn-1Gd (LZG811) alloy has the optimal discharge performance, with a discharge specific capacity of 1371.04 mA·g−1 at a current density of 40 mA∙cm−2, and its anode efficiency reaches nearly 70%. The poorer discharge properties of the Mg-8Li-2Zn-1Gd (LZG821) and Mg-8Li-2Zn-3Gd (LZG823) alloys are attributed to their refined grains, which could bring severe intergranular corrosion while increasing the grain boundary density.

Atomic-scale insight on nanostructures and electrochemical properties of (NiCrCo)82Ti9Al9 high-entropy alloy coatings by density functional theory calculations

(NiCrCo)82Ti9Al9 high−entropy alloy was attached to act as coating material by combining of laser cladding and laser remelting. In this study, the electrochemical properties of obtained HEA coatings were comparatively investigated using an electrochemical workstation, and the corrosion mechanism was revealed by the density functional theory calculations. The results show that the laser cladded HEA coating is mainly consisted of face-centered and body-centered cubic structures, and the face-centered cubic structure of the laser cladded HEA coating is transferred to the amorphous structure by laser remelting, which provides the stronger anti−corrosion capability compared with the face-centered cubic structure of HEA coating.

An In2O3/In2S3 photoanode-driven whole-cell biocathode sensor for sensitive detection of nitrate

Whole-cell biocathode sensor is a new form of self-regenerable biosensor and promising for environmental monitoring especially in the scenario with low organic substrate. However, external power supply such as electrochemical workstation is required to drive the biocathode reaction, which greatly limits its application. Herein, a new strategy based on the visible-light-driven whole-cell biocathode was proposed and validated for self-powered sensitive detections. To be specific, 1-OH phenazine was selected as the optimal electron shuttle for a Shewanella oneidensis MR-1 inoculated biocathode, which efficiently mediate the cathodic reaction at an electrode potential below −0.6 V (vs. SCE). Meanwhile, an In2O3/In2S3 photoanode with nanoflower-like structure was fabricated to match the kinetic of the biocathode. The photo-driven biocathode reduction was convinced by comparing with the performance of biocathode in the conventional three-electrode system. With this basis, a self-powered whole-cell biocathode sensor was developed for nitrate detection. An extreme low limit of detection of 0.028 μM (S/N=3) and linear detection range of 0.1–20 μM was achieved. Moreover, this biocathode sensor also exhibited excellent selectivity, reusability, accuracy, stability and was reliable for the detection of complex environmental samples. Therefore, this work developed a new photo-driven whole-cell biocathode sensor with excellent detection capacity of nitrate, which opens up new prospects for the development of high-performance biosensors.

Investigation of corrosion resistance offered by the Fe-based clad layer under salt spray and electrochemical workstations

The present work aims to evaluate the electrochemical characteristics of the Fe–based alloy coating formed on the 27SiMn steel substrate under neutral salt spray and 3.5 wt% NaCl environments. By adopting the high-speed laser cladding technique, the Fe-based clad layer was fabricated to perform microstructural and electrochemical characterizations. The microstructure and phase of the coating were analyzed using a scanning electron microscope (SEM), electron backscatter diffraction (EBSD) and X-ray diffraction (XRD), and its corrosion performance was also discussed using the salt spray corrosion chamber and the electrochemical workstation. The results show that the microstructure of the coating surface contains equiaxed crystals and long dendritic crystals which arise due to the higher solidification rate after the cladding process. The Fe–based coating was rich in FeCr phase throughout its microstructure without the formation of the intermetallic compounds. Compared to the substrate, the corroded surface of the coating tends to be compact containing a few corrosion pits after different corrosion times, which is attributed to the formation of Cr oxide on it. The electrochemical tests on the potentiodynamic polarization curve (PPC) and electrochemical impedance spectrum (EIS) indicate that the corrosion resistance of the coating is superior to the substrate, presenting a higher corrosion potential (−0.298 V), lower passive current density (1.36 × 10−6 A•cm2), and higher charge transfer resistance (8.23 × 106 Ω·cm2). Additionally, the corrosion mechanism of coating in salt spray and electrochemical tests is the local pitting corrosion due to the autocatalytic effect on the localized region, which facilitates Cl− ions penetrating the coating and leads to the dissolution of Fe and Cr oxides.

Effect of Ni on the corrosion resistance and passivation characteristics of Ni-Mn-Ga-Gd shape memory alloys in sodium chloride solutions

This paper investigates the effect of different Ni contents on the corrosion and passivation behavior of Ni54+xMn25Ga20.9-xGd0.1 (x = 0, 1, 2, 3, 4) shape memory alloy in a 3.5 wt% NaCl solution. Using scanning electron microscope, electrochemical workstation, and X-ray photoelectron spectroscopy. The results indicate that the corrosion resistance of single-phase alloys initially increases and then decreases as the Ni content ranges from x = 0 to 3, with the best corrosion resistance observed at x = 2. The passive film of the alloy mainly consists of NiO, Ni(OH)2, and Ga2O3. Both NiO and Ga2O3 positively affect the corrosion resistance of the passive film. In the range of 54 to 57 at% Ni content, the alloy remains a single-phase alloy. The elements Ni and Ga work together in the passivation film and at a Ni content of 56 at% to reach equilibrium, which provides the best corrosion resistance for single phase alloys. When the Ni content reaches 58 at%, the second phase appears in the form of a nickel-rich phase. Typically, intergranular corrosion preferentially corrodes the second phase, but in this study, the second phase is a nickel-rich phase with some corrosion resistance, which improves the overall corrosion resistance of the alloy.

Theoretical design and synthesis of Co30Ni60/CC for high selective methanol oxidation assisted energy-saving hydrogen production

The integration of methanol oxidation reaction (MOR) with hydrogen evolution reaction (HER) represents an advanced approach to hydrogen production technology. Nonetheless, the rational design and synthesis of bifunctional catalysts for both MOR and HER with exceptional activity, stability and selectivity present formidable challenges. In this work, firstly, density functional theory (DFT) was utilized to design and evaluate material models with high performance for both MOR and HER. Secondly, guided by DFT, Co30Ni60/CC (CC, carbon cloth) composites with a leaf-like nanosheet structure were successfully fabricated via electrodeposition. In the MOR process, Ni acts as the predominant active center, while Co amplifies the electrochemically active surface area (ECSA) and enhances the selectivity of methanol oxidation. Conversely, in the HER process, Co serves as the primary active center, with Ni augmenting the charge transfer rate. The electrochemical results demonstrate that Co30Ni60/CC exhibits exceptional performance in both MOR and HER at a current density (j) of 10 mA cm−2, with peak potentials of 1.323 V and −95 mV, respectively. Additionally, it shows remarkable selectivity for the oxidiation of methanol to high value-added formic acid. Thirdly, following a 100 h chronopotentiometry (CP) test, the required potential demonstrates an increase of 4.9 % (MOR) and 8.1 % (HER), signifying the superior stability of Co30Ni60/CC compared to those reported in the literature. The exceptional performance of Co30Ni60/CC can be primarily attributed to that the leaf-like nanosheets structure not only exposes a plethora of active sites but also facilitates electrolyte diffusion, the monolithic structure prepared by electrodeposition enhances its stability, and the transfer of electrons from Co to Ni regulates its electronic structure, as corroborated by X-ray photoelectron spectroscopy (XPS) and density of states (DOS) analyses. Finally, at the same j, the voltage required by the Co30Ni60/CC||Co30Ni60/CC electrolytic cell, powered by an electrochemical workstation, is 198 mV lower than that required for alkaline water-splitting. Meanwhile, at higher j (100 mA cm−2), the electrolytic cell exhibits sustained and stable operation for 150 h, enabling high-efficiency hydrogen production and the synthesis of high value-added formic acid.

Catechol/m-Phenylenediamine Modified Sol-Gel Coating with Enhanced Long-Lasting Anticorrosion Performance on 3003 Al Alloy.

Aluminum alloys, characterized by their low density and high mechanical strength, are widely applied in the manufacturing sector. However, the application of aluminum alloys in extreme environments presents severe corrosion challenges. Sol-gel organic coating techniques have garnered significant attention due to their excellent stability, barrier properties, and cost-effectiveness, as well as their simpler processing. Nevertheless, conventional sol-gel coatings are unable to withstand the corrosive effects of high-chloride and high-halide ion environments such as marine conditions, owing to their inherent structural defects. Therefore, this study proposes the utilization of a simple method to synthesize catechol (CA) and meta-phenylenediamine (MPD)-derived catecholamine compounds to modify sol-gel coatings. Surface characteristics of the modified coatings were analyzed using Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The thickness of the modified coating was approximately 6.8 μm. The CA/MPD-modified substance effectively densifies the sol-gel coating, enhancing its corrosion protection performance. A 3.5 wt% NaCl solution was used to simulate a marine environment, and electrochemical impedance spectroscopy (EIS) was conducted using an electrochemical workstation to evaluate the coating's protective properties over a long-term period. The results indicate that the modified coating provides protection for 3003 aluminum alloy for a minimum of 30 days under corrosive conditions, outperforming unmodified sol-gel coatings in terms of corrosion resistance.

Ultrasensitive and multiplexed Gastric cancer biomarkers detection with an integrated electrochemical immunosensing platform

Developing immunosensing platforms capable of simultaneously detecting multiple cancer markers is crucial for clinical diagnosis and biomedical research. Here, we introduce a novel dual-mode electrochemical biosensing assay platform capable of detecting two gastric cancer biomarkers: pepsinogen I (PG I) and pepsinogen II (PG II). Methylene blue (MB) and Prussian blue (PB) were used as dual signal sources to label PG I and PG II, respectively. The platform integrates an ARM STM32F411 microcontroller and an AD5941 analog front-end, which not only facilitates cyclic voltammetry (CV) and differential pulse voltammetry (DPV) with efficacy comparable to commercial electrochemical workstations but also offers data collection and synchronous analysis capabilities, allowing simultaneous output of PG I and PGR (PG I/PG II) values. Equipped with an interactive screen for operational control and result display, the immunosensing platform provides linear detection ranges for PG I (5 pg/mL–100 ng/mL) and PG II (50 pg/mL–200 ng/mL), enabling rapid detection within 5 min. It demonstrates excellent sensitivity and selectivity when comparing serum samples from healthy individuals and gastric cancer patients. The dual-marker detection platform significantly enhances early diagnosis and screening of gastric cancer, offering substantial improvements over single-marker assays. Furthermore, this platform shows potential for detecting multiple biomarkers in various diseases, highlighting its utility for biomedical applications.

Effects of Scanning Speed on the Microstructure and Wear Properties of Rockit 606 Coating Layer by Disk Laser Cladding.

Improving the wear resistance and corrosion resistance of 60Si2Mn steel is an important issue in agricultural machinery. A Rockit 606 coating layer may exhibit excellent performance in wear resistance and corrosion resistance. However, there are very a few public reports and articles involving the topic of a Rockit 606 laser cladding layer on a steel 60Si2Mn surface. It is of great importance to research Rockit 606 laser cladding layers. This work focuses on studying the microstructure and properties of Rockit 606 coating layers with different scanning speeds by disk laser cladding. Firstly, the laser cladding platform was designed and set up. Secondly, the laser cladding parameters were designed, and then the laser cladding experiment was conducted, and the Rockit 606 coating layers were obtained. And finally, the microstructure, phase distribution, corrosion resistance, surface hardness, and wear resistance of the coating layers were measured and analyzed. A scanning electron microscope (SEM), X-ray diffractometer (XRD), electrochemical workstation, and microhardness tester were used in this work. It was found that the microstructure Rockit 606 alloy coating consists of γ-Fe, V8C7, and Cr7C3. The microhardness of the Rockit 606 alloy coatings decreased with an increase in the scanning speed. When the scanning speed was 4 mm/s, the highest microhardness value reached 867.2 HV, which is about three times of that of the substrate. The average coefficients of friction (COFs) of the coatings decreased with an increase in the scanning speed, which led to the corresponding decrease of the wear rate. When the scanning speed was 4 mm/s, the wear behavior of the coating was mainly oxidative wear and a small amount of adhesive wear. The self-corrosion current density of the coatings prepared by laser cladding in a 3.5 wt.% NaCl solution is one order of magnitude lower than that of the substrate, indicating that the coatings have better corrosion resistance properties.

Superhydrophobic Corrosion-Resistant Coating of AZ91D Magnesium Alloy: Preparation and Performance

This research presents the development of a surface treatment for AZ91D magnesium alloy that exhibits both superhydrophobic and anticorrosive properties. Initially, a zinc-based phosphate film was deposited on the magnesium alloy surface. Subsequently, a composite coating with superhydrophobic properties was produced by surface modification using a fluorosilane-ethanol solution. The composite coating’s microstructure, chemical composition, wettability, self-cleaning, and anti-corrosion properties were evaluated using scanning electron microscopy, a contact angle measurement instrument, and an electrochemical workstation. The results demonstrated that the main components of the composite coating were P, O, Zn, F, and C. The static contact angle reached 158°, providing superior self-cleaning and acid and alkali corrosion resistance. Additionally, the charge transfer resistance and coating resistance of the composite coating were significantly higher than those of the magnesium alloy substrate, effectively preventing corrosion and preserving the surface from fouling.

Research on the Corrosion Resistance of Electrodeposited Ni-SiC Composites Constructed for Steel Storage Tank Application.

In this paper, the effects of the SiC phase incorporated in Ni substrate deposits on storage tank steel during electrodeposition at different current densities are explored. The microstructure, phase content, and corrosion resistance of the resulting Ni-SiC composites were investigated by scanning electron microscopy (SEM) matched with energy disperse spectroscopy (EDS), X-ray diffraction (XRD), and an electrochemical workstation, respectively. SEM micrographs and EDS results show that at 2.5 A/dm2, the composites presented a smooth and compact structure with high SiC content, while at 1.8 or 3.2 A/dm2, it became uneven and loose in structure with low SiC content. XRD patterns showed that the nickel grain size of composites firstly increased and then decreased with the growth of the current density. Notably, the Ni-SiC composite produced at 2.5 A/dm2 possessed a higher corrosion potential (-0.507 V) and lower corrosion current density (2.439 μA/cm2), illustrating that its excellent anti-corrosion ability was superior than that of other two composites. Hence, SiC co-deposited at 2.5 A/dm2 conducted as a protective barrier and inhibited the corrosion rate against a corrosion medium of Cl- and SO42- ions. In addition, the corrosion relationship illustrated that the SiC content of Ni-SiC composite firstly increased and then decreased with the growth of the current density, while the corrosion weight loss of Ni-SiC composites firstly decreased and then increased.

Investigating the Relationship between Building Orientation and Surface Properties of Stainless Steel Prepared via Selective Laser Melting

In our investigation of the influence rules and mechanisms of the building orientation on the surface properties of 316L stainless steel created via selective laser melting, we used X-ray diffractometry, scanning electron microscopy, and electron backscatter diffraction to investigate the phases, microstructures, and textures of specimens. In addition, we employed a digital microhardness tester, friction, and wear-testing apparatus, along with an electrochemical workstation, to examine variations in the surface properties. The results indicated that the surface phase compositions of the specimens with different building orientations were similar; however, they displayed anisotropic behavior in grain size, orientation, and texture. Notably, the surface densification of the specimens at 0°, 30°, 45°, and 60° initially decreased before subsequently increasing. In contrast, the surface roughness showed a pattern of first increasing and then declining. Moreover, the microhardness, wear resistance, and corrosion resistance decreased with an increasing inclination angle.

Enhanced adhesion and corrosion resistance through the modulation of a metallic Ti underlayer thickness

In this investigation, TiCN/TiN thin solid film was selected as a protective coating and deposited onto AZ31 alloy through reactive magnetron sputtering. To mitigate the potential failure resulting from the significant physical disparity between the ceramic film and the metal substrate, a Ti thin film was employed as a base layer. Following the deposition process, an analysis was conducted on the structural features, residual stress, fracture morphology, adhesion strength, and corrosion characteristics of the film/substrate system utilizing X-ray diffraction, scanning electron microscopy, scratch testing, and electrochemical workstation. The findings indicate that the incorporation of a Ti metallic underlayer significantly improves the adhesion and corrosion resistance of the TiCN film. However, when the thickness of the Ti layer surpasses 0.37 μm (deposition of 15 min), it leads to the formation of a distinct columnar crystal microstructure, increased residual stress, and diminished adhesion and corrosion resistance. Additionally, this study delves into the corrosion failure mechanisms in a chloride environment and explains the principles of residual stress measurement through XRD.

One-step hydrothermal method for long-term anti-corrosion lanthanum-based superhydrophobic coating on Mg alloy

The superhydrophobic coating was created on the surface of AZ31B using a one-step hydrothermal method. Various characterisation techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), contact angle goniometer, and electrochemical workstation, were employed to characterise its morphology, composition, hydrophobicity and corrosion resistance. The prepared coating from a 5-hour hydrothermal reaction exhibited a double-layer structure with a dense inner oxide layer and an outer layer of needle-like micro-nano structures. Achieving a water contact angle (WCA) as high as 159°, the superhydrophobic coating demonstrated low water adhesion and excellent self-cleaning properties. In a 3.5 wt-% NaCl aqueous solution, its corrosion rate was 5 orders of magnitude lower than that of the bare Mg alloy. Furthermore, the coating maintained a high impedance modulus value at 0.01 Hz (∼6.85 × 106 Ω cm2) after immersion in 3.5 wt-% NaCl solution for 25 days, which was attributed to the synergistic effect of the inner and outer layers. This study introduces a strategy for preparing long-term corrosion-resistant superhydrophobic coating on Mg alloy.

Quantitative characterization on influence of surface particles on corrosion behavior of multiarc ion plated CrAlN coatings

Surface particles on multiarc ion plated coatings are common defects, and their influence on the service performance of coatings is rarely defined. The CrAlN coatings were deposited on the tungsten steel (YG8) substrates using multiarc ion plating. The effects of the substrate bias voltages and nitrogen flow rates on the quantity of the surface particles were investigated, and the influence of the surface particles on the corrosion resistance of the coatings is quantitatively characterized. The morphology of surface particles was characterized using a scanning electron microscope. The quantity of the surface particles was counted by image software. The corrosion resistance of the coatings was evaluated through an electrochemical workstation. The results show that the quantity of surface particles decreased with the increase in the substrate bias voltage and nitrogen flow rate. The corrosion resistance of the coatings showed a positive correlation with the quantity of the surface particles, and it decreased dramatically when the quantity of the surface particles exceeded 111/10 000 μm2. The corrosion mechanism of the coatings was attributed to the defect-induced pitting corrosion.