Enhanced Corrosion Resistance Research Articles

Effect of alloy 625 buffer layer on corrosion resistance of nickel base hardfacing

Nickel base hardfacing alloys serve to mitigate corrosion losses at elevated temperatures. Efficacy of Nickel base hardfacing alloys can be compromised when applied onto Fe base substrates due to iron dilution in hardfacing. The degree of Fe dilution can be reduced by using advanced deposition methods and optimized deposition parameters. Gas Tungsten Arc Welding (GTAW) method is commonly employed for its cost-effectiveness and versatility, but it tends to induce higher Fe dilution due to increased heat input. This study aims to reduce the degree of Fe dilution and enhance corrosion resistance by introducing a nickel base buffer layer (alloy 625) between the nickel base hardfacing alloy and AISI 316L stainless steel substrate. For comparative purposes, Ni base hardfacing alloy was deposited on the substrate without any buffer layer. Hardfacing depositions were prepared using manual GTAW process. Process parameters namely, deposition current, voltage, travelling speed, pre-heating temperature, and cooling method were kept constant. Samples underwent aging at 1123 K for 4 h, followed by microstructural examination via optical and scanning electron microscopes. Iron (Fe) dilution quantification was performed using energy dispersive spectroscopy (EDS). The EDS analysis showed that the use of buffer layer between the hardfaced deposit and the substrate decreased the degree of Fe dilution in the hardfaced deposit. X-Ray diffraction (XRD) analysis was performed to identify various phases formed in the hardfaced deposit. Potentiodynamic polarization test was performed to assess the corrosion resistance of hardfaced deposit in 3.5 wt% NaCl solution. Results show significant improvement in corrosion resistance of hardfacings deposited sample with buffer layer as compared to those without buffer layer. Aging treatment further enhanced corrosion resistance. The corrosion resistance data is correlated with the microstructure and phases formed in various samples.

Dense Al2O3 sealing inhibited high hydrostatic pressure corrosion of Cr/GLC coating

The corrosion failure of amorphous carbon (a-C) coatings is commonly ascribed to the existence of growth microdefects, which serve as pathways for corrosive fluids to permeate the substrate. Atomic layer deposition (ALD) is renowned for its ability to augment the corrosion resistance of metallic materials. Graphite-like carbon (GLC) is one of the amorphous carbon materials dominated by hybridized sp2-C bonds. In this study, an ALD-deposited Al2O3 layer is specially introduced on the Cr/GLC multilayer coating to solve the aforementioned corrosion risk of a-C by taking the sealing conception for defects. Compared to the as-deposited Cr/GLC coating, the coating encapsulated with Al2O3 layer depicts the reduction of corrosion current density over two orders of magnitude under a wide pressure range of 0.1 ~ 15 MPa. Particularly, the presence of released Crn+ and Fen+ in the corrosion solution is significantly diminished, accompanying with a small quantity of Aln+ generated in sealed coating during corrosion. Microstructural analysis and electrochemical results identified that both the dense Al2O3 layer offered strong safeguard for Cr elements released from multilayers, whilst amorphous carbon network inhibited the likelihood chloride penetration induced by partially infiltrated Al2O3, which made the synergistic contributions to the enhancement of corrosion resistance for Cr/GLC coating for deep-sea applications.

Efficient dual defense: PDA-Cu coating for simultaneous corrosion resistance and antibacterial protection of Mg alloys

The corrosion problem of Mg alloys remains a significant barrier to their technical applications. Particularly challenging is meeting specific functional requirements while enhancing corrosion resistance. Here, a novel metal organic composite coating (PDA-Cu) has been developed, exhibiting excellent corrosion resistance, strong bonding strength, and potent antibacterial properties. In 3.5 wt% NaCl solution, the corrosion rate of PDA-Cu alloy was significantly lower than that of bare Mg alloy, about 1/360; it had a strong inhibition rate (100%) and high binding strength (23.75 N). Importantly, the composite coating maintains consistency across various substrates and forms, proving its adaptability and expanding its potential applications.

The Effects of Cl− and selected deoxidizers on the high temperature corrosion electrochemistry of alloy 690 in nuclear steam generator water

ABSTRACT The heat transfer tube in a steam generator serves as a critical heat exchange component in the primary and secondary loops of pressurized water reactor (PWR) nuclear power plants. The corrosion resistance of the heat transfer tube material directly influences the longevity of PWR nuclear power plants. This study investigated the electrochemical corrosion properties of 690 alloy (UNS N06690) in a simulated secondary water environment of PWR, focusing on different chloride ion concentrations and combinations of deoxidizers. The findings reveal a gradual decrease in the corrosion potential of 690 alloy, accompanied by an increase in self-corrosion current and a progressive reduction in the passivation range, ultimately leading to its disappearance as chloride ion concentration rises from 0 μg·L−1 to 500 μg·L−1. Moreover, the impedance value of the inner film exhibits a declining trend with increase of chloride ion concentration. Conversely, the resistance value of the outer film remains relatively stable while the size and spacing of oxide particles on the surface of the 690 alloy continuously increase. This observation suggests that chloride ions primarily influence the formation of the inner passivation film, which in turn determines the corrosion resistance of the 690 alloy. Notably, the performance of the 690 alloy is similar when the deoxidizer combination is ammonia(NH3)+erythorbic acid(ERA) or NH3+hydrazine(N2H4), demonstrating the ability to form a relatively complete passivation film and exhibit improved corrosion resistance compared to NH3+N-isopropyl hydroxylamine, additionally, when the deoxidizer combination is NH3+N2H4, the 690 alloy exhibits lower self-corrosion current density across different chloride ion concentrations, indicating enhanced corrosion resistance.

Effect of hydrophobicity in hybrid sol-gel coating for enhanced barrier property on mild steel

Hydrophobic coatings have generated growing interest in mitigating the deterioration of metals against corrosion due to their water-repellency properties. For organic-inorganic hybrid (OIH) coatings derived from Sol-Gel, enhancing their hydrophobicity is an efficient way to limit the diffusion of corrosive species to the substrate through the mesopores and low-density zone. This research successfully applied crack-free multicomponent Sol-Gel coating based on zirconium oxide and silicate on mild steel. By doping Octadecyltriethoxysilane (ODTES) with an alkyl group (C18), the coating's hydrophobicity was tailored either on its surface or within the mesopore structure. It was proved in the first place that the enhancement of corrosion resistance is mainly due to the microcapillary effect rather than the surface wettability. Moreover, the effect of the alkyl group addition depends strongly on the coating's microstructure, which is determined by the Sol composition. The most promising composition arose from balancing the coating's density and hydrophobicity. So-prepared samples showed a low current density with increasing potential, which is four orders of magnitude lower than that of the bare substrate. Until a critical potential, denoted Ec, the corrosion species were driven by the electrostatic force to the underlying metal.

Desensitization of AA5083 alloy via pulsed laser irradiation and its microstructural mechanism

In the present work, a laser surface desensitization (LSD) method was carried out on sensitized AA5083 alloy with the underlying microstructural evolution examined. The enhanced corrosion resistance after LSD process was confirmed by nitric acid mass loss test (NAMLT), immersion test and electrochemical measurements, which is mainly ascribed to the modification of grain boundary chemistry. Accompanied with the dissolution of grain boundary β (Al3Mg2) phase during LSD process, the grain boundaries could be characterized by Mg segregation or nano-sized Mg-rich clusters, which may also be absent from chemical uniformity depending on grain boundary misorientation.

Irradiation-decelerated corrosion behavior of CrN/TiSiN multilayer coating in Liquid Pb-Bi eutectic alloy

CrN/TiSiN multilayer coatings deposited at 316L substrate were selected to explore the effects of irradiation on LBE (Liquid Pb-Bi eutectic alloy) corrosion. The as-deposited and irradiated coatings were exposed in LBE. After exposure, all CrN/TiSiN coatings presented oxidation accompanied with PbBi penetration. Irradiated coatings revealed better corrosion resistance with thinner oxide layer and smaller penetration thickness. The largest decrement of 39% in oxidation thickness was observed in CrN/TiSiN deposited with Ti80Si20 under 150V. The irradiation-decelerated LBE corrosion could be attributed to the rapidly formed protective oxide layer resulting from the irradiation defects which accelerated nucleation and diffusion process during oxides formation. The decelerated effect was relatively weak in coatings deposited with a bias voltage under 100 V, in which the decrement is under 10%. The enhanced corrosion resistance was attributed to the quickly formed dense and continuous chromium oxide which rapidly formed due to the irradiation induced defects and acted as diffusion barrier to slow down LBE penetration.

Essential role of Si in enhancing corrosion resistance of high strength low alloy steels in marine environment

High strength low alloy steels are extensively applied in marine engineering structures (cross-sea bridge, ocean platform, etc), which are usually subjected to severe corrosion in marine atmosphere. In this work, the corrosion behaviors of 550MPa-grade high strength low alloy marine steels with varied Si content were studied in simulated marine atmosphere. Results show the increase of Si could significantly facilitate the formation of α-FeOOH and enrichment of Cr and Cu in inner rust layer, making the rust layer compact and cation-selective. Si and Cr can be co-enriched in inner rust layer to form mixed or complex oxides with amorphous network structure, which could greatly improve the compactness and stability of rust layer and thereby enhance the corrosion resistance of low alloy steel.

Alternating C- and Ti-dominated sublayers on bipolar plates achieve enhanced corrosion resistance under high potentials toward proton exchange membrane fuel cells

High cathodic transient potentials accelerate the dissolution of metal bipolar plates, and developing corrosion-resistant coatings is imperative. A multilayer coating that C and Ti alternatively dominated the sublayers is fabricated on SS316L (C/Ti/SS). Such an optimized composition and structure significantly expands transpassive potential to 1.6V and thus offers full protection within the entire working potential range of proton exchange membrane fuel cells. After 10000 cyclic polarizations with Epeak of 1.6V, a conductive TiO2 nanofilm forms on the surface and C/Ti/SS achieves a noticeable interfacial contact resistance of 9.43 mΩ∙cm2, highlighting the remarkable commercial application of the novel coating.

Enhanced corrosion resistance of 9Cr alloy steel via Al alloying in simulated harsh marine atmosphere

The corrosion behaviors of Cr9Ni1 and Cr9Ni1Al in simulated harsh marine atmosphere were studied by dry-wet cyclic test (DWCT). Scanning electron microscopy (SEM), energy disperse spectroscopy (EDS) and electron probe microanalyzer (EPMA) were used to observe the cross-section morphology of rust layer. The composition of corrosion products were analyzed through X-ray diffractometer (XRD) and X-Photoelectron spectroscope (XPS). Electrochemical impedance spectroscopy (EIS) was used to determine the electrochemical properties of rusted samples. The results show that the corrosion rate of both 9Cr alloy steels increases continuously during the initial corrosion process of 576 h, which can be understood from α/γ*>1 of the rust layer and the acidification caused by increased CrO3. Interestingly, the addition of 0.7% Al reduced the corrosion rate of 9Cr steel by more than 26%. Al not only generates Al2O3 and Al(OH)3 enriched in the whole rust layer, but also optimizes the rust layer in terms of the Cr distribution, composition of Cr-containing compounds, and α-FeOOH content. Importantly, it is proposed that Al alloying weakens acidification through reducing CrO3 content and partial dissolution of the generated Al(OH)3.

The effect of doping different amounts of boron on the corrosion resistance and biocompatibility of TiO2 nanotubes synthesized on SLM Ti6Al4V samples

This comprehensive study investigates the corrosion and biocompatibility performances of boron-doped TiO2 nanotubes (TNT) synthesized on Ti6Al4V alloy produced by the selective laser melting (SLM) process. Structural analysis reveals a consistent reduction in nanotube diameter across varying boron doping levels (0.05 - 2 M boric acid doping), with B4-TNT exhibiting the smallest diameter at 190 nm. Boron incorporation induces phase transformation and decreases in diameter of nanotubes, influencing the material's structural properties. Corrosion resistance assessments indicate a significant enhancement, with B4-TNT demonstrating the highest polarization resistance (Rt = 2849.03 kΩ.cm2). The observed improvements are attributed to the combination of reduced nanotube diameter, altered phase structure, and increased polarization resistance, collectively contributing to enhanced corrosion resistance. Biocompatibility experiments conducted with human fibroblast cells (HDFa) reveal that B-doped TNTs foster increased cell viability compared to undoped TNT and uncoated alloy surfaces. These findings underscore the potential of boron doping as a strategic approach to improve corrosion resistance and enhance the biocompatibility of Ti6Al4V implants. This study provides valuable insights for advancing materials in biomedical applications with improved structural, corrosion-resistant, and biocompatible properties.

Microstructure and Corrosion Behavior of Ti-10Cu Fabricated by Selective Laser Melting

This study investigates the influence of scan rotation and remelting on the microstructure and corrosion performance of Ti-10Cu alloy fabricated via selective laser melting (SLM). By analyzing the interplay between processing parameters and material properties, the work provides key insights for optimizing SLM-produced Ti-Cu alloys for improved functionality. Our work demonstrates that combining simultaneous remelting with reduced scan rotation yielded a homogenous microstructure with lower stress, surpassing the benefits of copper alone. This optimized configuration led to the highest polarization resistance (9 MΩ cm²) and thickest passive layer after simulated body fluid immersion, showcasing the synergism between process control and alloying for enhanced corrosion resistance. This opens doors for tailoring SLM-produced Ti-10Cu for demanding biomedical and marine applications.

Green synthesis and characterization of binary, ternary, and quaternary Ti/MMO anodes for chlorine and oxygen evolution reactions

Dimensionally stable anodes of titanium (Ti) metal coated with mixed metal oxides (MMO) are widely used in several electrochemical applications, especially chloro-alkali electrolysis. Herein, we deposited MMO coatings on Ti substrates in different compositions, namely, (60%RuO2-40%TiO2), (60%RuO2-30%TiO2-10%IrO2), and (60%RuO2-20%TiO2-15%IrO2-5%Ta2O5), where RuO2 has the same percentage ratio in all coatings. The aim was to use these electrodes for chlorine evolution reaction (CER) and oxygen evolution reaction (OER) applications. Electrochemical characterization of the coated samples was performed to identify the best Ti/MMO electrodes with the highest efficiencies among the various prepared combinations. The role of IrO2 and Ta2O5 in enhancing corrosion resistance and electrochemical efficacy was up for debate. Scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses were exploited to determine the surface morphology, chemical composition, crystallinity, surface composition, and chemical states of the acquired coatings. The differential scanning calorimetry (DSC) method was used to evaluate the apparent activation energy (Ea\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{\ ext{E}}}_{{\ ext{a}}}$$\\end{document}) of the deposited MMO. Additionally, the electrochemical performance of our designed coatings was scrutinized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), a current on–off test, a CV stability test (ST), and an accelerated stability test (AST). Furthermore, linear sweep voltammetry (LSV) was incorporated to assess the catalytic efficacy of the prepared anodes toward the CER in a brine solution of pH 2 and the OER in 1 M H2SO4. It became clear that the CER and OER incurred almost the same potential value (1.1 V) on both Ti/RuO2-TiO2 and Ti/RuO2-TiO2-IrO2 electrodes. However, on the Ti/RuO2-TiO2-IrO2-Ta2O5 anode, there was a 0.2 V potential difference between the CER occurring at 1.1 V and the OER happening at 1.3 V.

Seamlessly embedded microcapsules in self-repairing coatings: Improved compatibility and enhanced corrosion resistance recovery

Microcapsules, with polyether amine as the core repairing agent and polyether amine-cured epoxy as the shell, were prepared via the multiple emulsion polymerization and applied in an epoxy/polyether amine coating system on carbon steel surfaces. The microcapsules and the coating substrate have the same composition and are seamlessly connected by chemical bonds, akin to the direct injection of liquid healing agents into the substrate. When the repairing agent flows out, it will crosslink and cure with the epoxy groups in the substrate to achieve no difference self-repair. The characteristics of microcapsules were studied by scanning electron microscope (SEM), Fourier transform infrared (FTIR) and Thermal gravimetric (TG). The mechanical properties and corrosion resistance recovery of coatings loaded of coatings with different weight percentages of loaded microcapsules were investigated using tensile testing, electrochemical impedance spectroscopy (EIS) and neutral salt spray test (NSS). Results indicate that the 7 wt% microcapsules composite coating shows a 37.7 % increase in tensile strength and a 71.4 % increase in fracture toughness over pure epoxy coating. After immersing in saltwater for 7 days, the scratch sealing efficiency can reach 99.85 %. The coating system not only improved the compatibility between microcapsules and the substrate, but also enhanced the toughness of thermosetting brittle epoxy materials, giving it long-lasting anti-corrosion capability.

Robust and efficient Iron-Based electrodes for hydrogen production from seawater at high current density above 1000 mA cm−2

The implementation of cheap iron-based catalysts for seawater electrolysis at high- current–density offers an economical and sustainable solution for industrial hydrogen production in near future. However, Fe-based electrodes suffer from poor intrinsic activity and corrosion resistance in seawater, resulting in unsatisfactory seawater splitting performance. Here, we reported the scale-up fabrication of whole-Fe-based electrodes (NiFe-X (X = O, P) NAs/Fe foam) by facile soaking-phosphating. Surface active layers exhibit enhanced corrosion resistance compared to bare Fe foam, and trace Ni modification lowers reaction energy barriers of cathodic NiFeP and in-situ generated anodic NiFeOOH, respectively. Thus, NiFe-P||NiFe-O pair only requires 1.93 V to deliver 3000 mA cm−2 at 6 M KOH, 60 °C for overall seawater splitting, and works stably for 200 h at 1000 mA cm−2. Furthermore, NiFe-X (X = O, P) NAs/Fe foam show impressive adaptation to fresh water/tap water/seawater and all kinds of renewable energies, presenting excellent flexibility for various environmental applications and scenarios.

Effect of recrystallization degree on properties of passive film of super ferritic stainless steel S44660

Abstract The effect of the recrystallization degree on the properties of passive films formed in 0.1 M HNO3 solution for super ferritic stainless steel S44660 was examined in this study. The initial specimens, in their cold-rolled state, showed a high dislocation density, as observed through electron backscatter diffraction (EBSD) experiments. Analysis of potentiodynamic polarization (PDP) curves and electrochemical impedance spectroscopy (EIS) measurements suggested that with the increase of recrystallization degree, the corrosion current density reduced and the corrosion potential increased. As revealed by Mott–Schottky analysis, the passive film showed a dual structure of n-type and p-type semiconductors, with the carrier density of the passive film decreasing as the recrystallization degree increased. X-ray photoelectron spectroscopy (XPS) provided insights into the film composition, indicating that the Fe2O3 and Cr2O3 content, which improved the stability of the passive film, increased with the degree of recrystallization. In summary, the increase in recrystallization degree reduced the number of defects in the microstructure, thereby creating favorable conditions for the formation of highly protective passive films. The passive film formed after complete recrystallization exhibited enhanced corrosion resistance.

Research on the Solid-Liquid Composite Casting Process of Incoloy825/P110 Steel Composite Pipe.

Bimetallic composites have a wide range of application prospects in various industries. Different bonding temperatures, as one of the influencing factors, directly affect the bonding effectiveness as well as the performance and application of the materials. Using metallurgical bonding techniques ensures a strong bond at the interface of bimetallic materials, resulting in high-quality composite pipe billets. This paper describes an Incoloy825/P110 steel bimetal composite material made by the solid-liquid composite method. By utilizing ProCAST 14.5 software for simulation and deriving theoretical formulas, an initial range of temperatures for bimetallic preparation has been tentatively determined. And this temperature range will be utilized for on-site experiments to prepare bimetallic samples. After the preparation process is completed, samples will be selected. The influence of the external mold temperature on the interface bonding of Incoloy825/P110 steel solid-liquid composite material is studied using an ultra-depth three-dimensional morphology microscope and a scanning electron microscope. Through research, the optimal preheating temperature range for the solid-liquid composite outer mold of Incoloy825/P110 bimetallic composite material has been determined. The casting temperature of the inner mold has a significant impact on the interface bonding of this bimetal composite material. As the casting temperature of the inner mold increases, the interface thickness gradually increases. At lower temperatures, the interface thickness is lower and the bonding is poorer. At higher temperatures, melting may occur, leading to coarse grains at the interface. When the temperatures of the inner and outer molds are within a certain range, a new phase appears at the interface. Indeed, it increases the strength of the interface bonding. Due to co-melting of the bimetal near the interface, element migration occurs, resulting in increased Ni and Cr content at the interface and enhanced corrosion resistance.

Effects of electroless nickel -coating on tribological and corrosion behaviour of TMT steel rebar with multi-walled carbon-nanotube and titanium dioxide nanoparticles

This study incorporated Multi-walled carbon nanotube particles (MWCNTs) and Titanium Dioxide Nanoparticles (TiO2) into a metal matrix composite in Ni–P coated substrate using an Electroless technique. This study significantly improves the tribological properties, enhances corrosion resistance, increases durability and extends the service life of coated rebar. Coated rebar helps make infrastructure more sustainable by extending the life of buildings and lowering their material consumption, trash output, and ecological footprint. The tribological behaviour of steel rebar has been studied by using a variety of characterization techniques, like X-ray diffraction, Atomic Force Microscopy, Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (EDX) including the corrosion test and the hardness test. The topographical roughness of the bare specimen, Ni–P coated specimen, CNT coated specimen and TiO2 coated specimen are 67.4 nm, 112 nm, 201 nm, and 162 nm respectively. The microhardness of the bare substrate, Ni–P coated, CNT doped coated, and TiO2 dopped coated specimens was done using Vicker's Hardness tester and the mean values were 455 HV, 580 HV, 810 HV, and 680 HV respectively. Resistance to corrosion of TMT steel rebar of Fe500 was examined using the polarisation method and Electrochemical-Impedance-Spectroscope (EIS) method. These techniques were examined in 3.5 wt% aqueous medium of NaCl and analysed the Ecorr (corrosion potential) and Icorr (Corrosion current density) of the bare substrate, Ni–P coated, Ni–P/CNT and Ni–P/TiO2 substrate. The corrosion inhabitation efficiency of the Ni–P-CNT doped was 22.5% more than the Bare substrate, and the TiO2 doped coated specimen was 10.63% more than the bare substrate. Resistance to corrosion of the CNT-coated substrate is better than Ni–P/TiO2 and Ni–P-coated specimens.

Galvanic Corrosion Behavior of the X80 Steel Welded Joint

Wire beam electrode techniques and classical electrochemical techniques were used to investigate the effect of the area ratio of each part of the welded joint on the galvanic corrosion behavior. The results showed that the order of the corrosion current density of the different regions in the simulated X80 steel welded joint was as follows: coarse-grained heat-affected zone > fine-grained heat-affected zone > intercritical heat-affected zone > base metal > weld metal. As the area ratio of weld metal increased, the galvanic potential shifted positively, the maximum anode galvanic current density increased and the main anode galvanic effect increased. On the other hand, as the area ratio of the base metal and the heat-affected zone decreased, the coupled potential shifted negatively and the maximum anode galvanic current density decreased. The galvanic corrosion intensity of the simulated X80 steel welded joint increased as the area ratio of the weld metal decreased and increased as the area ratio of the heat-affected zone and base metal increased. To enhance corrosion resistance, it is advisable to choose a shape with a larger groove to increase the WM area in the welded joint. Additionally, selecting a welding method with lower heat input and a higher energy density can help reduce the HAZ area in the welded joint.

Morphological stability of electrostrictive thin films

A large electric field is typically present in anodic or passive oxide films. Stresses induced by such a large electric field are critical in understanding the breakdown mechanism of thin oxide films and improving their corrosion resistance. In this work, we consider electromechanical coupling through the electrostrictive effect. A continuum model incorporating lattice misfit and electric field-induced stresses is developed. We perform a linear stability analysis of the full coupled model and show that, for typical oxides, neglecting electrostriction underestimates the film’s instability, especially in systems with a large electric field. Moreover, a region where electrostriction can potentially provide a stabilizing effect is identified, allowing electrostriction to enhance corrosion resistance. We identified an equilibrium electric field intrinsic to the system and the corresponding equilibrium film thickness. The film’s stability is very sensitive to the electric field: a 40 percent deviation from the equilibrium electric field can change the maximum growth rate by nearly an order of magnitude. Moreover, our model reduces to classical morphological instability models in the limit of misfit-only, electrostatic-only, and no-electrostriction cases. Finally, the effect of various parameters on the film’s stability is studied.