Conventional Coatings Research Articles

Durable anti-icing coating with stability based on self-regulating oil storage layer

In recent years, slippery liquid-infused porous surfaces (SLIPSs) have emerged as a potential alternative to superhydrophobic surfaces (SHSs) due to their exceptional anti-icing properties. However, the current challenge lies in the significant lubricant consumption of SLIPSs, which poses a major obstacle to coating durability. In this study, we developed a durable anti-icing coating with stability (DASS), which combines SHSs and SLIPSs. By incorporating high adsorption particles and low cross-linking density rubber into the oil storage layer, the coating achieves an increased oil storage capacity while effectively inhibiting lubricant loss. Additionally, a superhydrophobic layer is introduced on the surface to ensure surface lubrication and prevent lubricant depletion. The three-layer structure enables the coating to maintain a low τice (<20kPa) during 30 icing/deicing cycles, showcasing superior de-icing durability compared to conventional anti-icing coatings. Interestingly, the original anti-icing properties of the coating can be restored through external oil replenishment. Furthermore, this coating exhibits excellent resistance against fouling, mechanical stress, chemical exposure, temperature variations, and weathering effects, making it highly suitable for practical applications in anti-icing coatings.

Eco-friendly coatings composed of lignosulfonate-modified biopolymer and vegetable waxes for nitrogenous fertilizers

Fertilizer coatings are considered mandatory to protect the physical quality of fertilizer granules. They continue to be developed due to compliance with novel fertilizer types and, most importantly, future environmental and animal-plant health regulations. As known, bio-based contents are sustainable and eco-friendly compared to petroleum-based materials. However, many types of coatings are commonly composed of unsustainable, costly, and can be ecologically toxic, such as paraffin or mineral oil. This article presents a comparative research study to provide eco-friendly anticaking coatings composed of lignosulfonate-modified biopolymer and vegetable waxes instead of conventional coatings. This research mainly aims to find alternative ingredients instead of a petroleum-derivatives in conventional coatings. According to the results, an anticaking coating containing lignosulfonate-modified biopolymer improved the granule structure of calcium ammonium nitrate fertilizer. It showed the best anticaking performance compared to other coating types. Vegetable-based coatings, on the other hand, gave results in appropriate intervals, especially at low concentrations, and showed a valuable way to develop better versions in future studies. As a result, it is seen that biopolymers can replace paraffin-based products.

Изучение модификатора битума на основе низкомолекулярных каучуков

The issue of road surface quality has always been relevant for Russia, especially in conditions of modern heavy traffic. Conventional asphalt concrete coatings based on bitumen cannot provide the required physical and mechanical properties and durability. However, the use of a new bitumen modifier based on low molecular weight rubbers, containing active substances that change the molecular structure of bitumen, allows to improve its properties, such as penetration, there is an improvement of 30%, frost resistance increases by 10-15 ° C, there is also an increase in the softening temperature of bitumen by 2-5 ° C, the limit increases strength by 10-30%. This leads to the creation of a stronger and more durable road surface. In addition, such a modifier can be used to modify other materials, which allows you to create new materials with improved properties and extend the service life of roads.

Application of waste raw materials as a reinforcement for protective coatings based on pyrophyllite

In this study, pyrophyllite was used for the first time in the composition of protective refractory coatings together with supplementary waste resources. The proposed refractory coatings are applicable for metallic and non-metallic structures, with the option of using them to protect machinery components in the chemical industry, metallurgy, and mining. Given that pyrophyllite has a low hardness, the goal was to improve the coating's resistance to cavitation erosion by adding 20 wt.% of hard refractory materials, i.e., crushed and micronized waste bricks based on mullite and corundum, respectively. Previous studies have demonstrated that protective coatings using a pyrophyllite filler have refractory qualities but insufficient resistance to cavitation erosion. As a result, the composition of refractory coatings, the preparation techniques, and the coating manufacturing process were altered. This study presents a simple method for combining conventional coatings made of refractory fillers (primary resource: pyrophyllite) with waste materials (mullite brick and corundum brick) used as reinforcement in protective refractory coatings for metal and non-metal structural elements that are highly resistant to cavitation erosion.

An Analysis of the Influence of Cool Roof Thermal Parameters on Building Energy Consumption Based on Orthogonal Design

An analytical hierarchy model of the impact of solar reflectance, thermal emittance, heat transfer coefficient, and heat storage coefficient on building energy consumption was established through the implementation of orthogonal design experiments. The EnergyPlus software (v9.0.1) was utilized to simulate building energy consumption across diverse climatic regions in China, providing essential benchmarks for the orthogonal design. The results of the range analysis consistently indicate that, barring regions characterized by extremely cold climates, solar reflectance emerges as the predominant factor exerting an influence on building energy consumption. As geographical latitude increases, the impact of the heat transfer coefficient becomes progressively larger, while the weight of thermal reflectance concurrently diminishes. Drawing upon the principles rooted in the gradient refractive rate theory and the concept of atmospheric window radiation, a range of high-reflectance and high-emittance cool roof coatings in various colors were meticulously developed. A spectrophotometer was employed to precisely quantify their reflectance properties, and simulations were subsequently conducted to scrutinize their energy-saving characteristics. The results demonstrate that the cool roof coatings that were developed using the methodology described in this paper exhibit substantial enhancements in reflectance, with increases of 0.24, 0.25, 0.37, and 0.35 for the yellow, red, blue, and green cool roofing materials, respectively, in comparison to conventional colored coatings. Under typical summer conditions, these enhancements translate to significant reductions in roof temperatures, ranging from 9.4 °C to 14.0 °C. Moreover, the simulations exploring the cooling loads for the roofs of differing colors consistently revealed remarkable energy savings. These savings were quantified to be 4.1%, 3.9%, 5.5%, and 5.4%, respectively, when compared to conventional coatings of the corresponding colors. These findings offer valuable insights into strategies for optimizing the energy efficiency of buildings through the application of high-reflectance cool roofing materials.

Black Silicon as Anti-Reflective Structure for Infrared Imaging Applications.

For uncooled infrared cameras based on microbolometers, silicon caps are often utilized to maintain a vacuum inside the packaged bolometer array. To reduce Fresnel reflection losses, anti-reflection coatings are typically applied on both sides of the silicon caps.This work investigates whether black silicon may be used as an alternative to conventional anti-reflective coatings. Reactive ion etching was used to etch the black silicon layer and deep cavities in silicon. The effects of the processed surfaces on optical transmission and image quality were investigated in detail by Fourier transform infrared spectroscopy and with modulated transfer function measurements. The results show that the etched surfaces enable similar transmission to the state-of-the-artanti-reflection coatings in the 8-12 µm range and possibly obtain wider bandwidth transmission up to 24 µm. No degradation in image quality was found when using the processed wafers as windows. These results show that black silicon can be used as an effective anti-reflection layer on silicon caps used in the vacuum packaging of microbolometer arrays.

Multilayering of conventional latex-based dispersion coatings containing small amounts of silica nanospheres: Runnability on a pilot scale flexographic coater and barrier performance

The addition of functional coatings to packaging materials is a key requirement for increasing their performance and creating innovative packaging solutions. Flexography, a cost-effective printing method commonly used to print information and graphics directly onto a wide variety of packaging substrates, shows good potential for applying functional coatings. In this study, conventional clay-latex coating formulations containing approximately 1.3 wt% silica nanospheres were applied to a linerboard using a pilot scale flexographic printing web press. The performance of multilayered silica nanosphere-based coatings was compared with conventional coatings containing talc and/or wax dispersion in terms of coating grammage, runnability, and barrier performance. Coating grammage increased with an increased number of coating layers and a significant decrease in both the water vapor transmission rate (WVTR) and the direct water uptake of water (Cobb 120 wettability test) was observed for coatings containing silica nanoparticles. In general, the silica nanosphere-based coatings performed better than talc-based coatings. Talc/wax-based coatings had the highest variation in surface roughness due to an uneven distribution and variations of coating layers.

Colloidal crystals array enabled bionic biliary stent for efficient domestic biofluid management

In vivo surgical interventions require effective management of biofluids, including controlling bleeding and removing excess biofluids such as bile, wound exudate, and blood. To address these issues, recent advances have emerged, such as self-sealing needles, drug-eluting stents, and shear-thinning hydrogels. However, complications associated with intestinal mucosal injury and secondary damage still persist. Therefore, a multifunctional stent is urgently required that can effectively remove excessive biofluid. Surface wettability of biliary stents is crucial in biofluid management, and conventional coatings can cause adhesion to wound tissue. To overcome this issue, we developed an interpenetrating Janus wettability stent coating, enabling unidirectional draining of excessive biofluid from its hydrophobic side to hydrophilic side, thereby preventing biofluid from wetting the wound. Furthermore, we demonstrate a directional biofluid movement using a self-pumping dressing in an infected tissue model, providing a new approach for in situ biofluid collection and disease diagnosis by detecting metal ion changes. Overall, our integrated system presents an opportunity to design wound dressings with effective biofluid management and metal ion detection capabilities.

Nanocone-shaped Ni-electroplated carbon fiber composite films for electromagnetic shielding applications

This study developed a series of lightweight composite films with adjustable reflectivity and superior mechanical properties. Carbon fiber (CF) was electroplated with both conventional and nanocone-shaped Ni coatings to create Ni-plated carbon fiber (CF@Ni), which was then further classified into conventional Ni carbon fiber (CF@CN) and nanocone-shaped Ni carbon fiber (CF@NN). CF@Ni fibers were sheared and filtered to produce Ni-plated carbon fiber fabric (CFF@Ni), which was then encapsulated in polyimide resin (PI) to form the final thin film materials (CF@Ni/PI). The shielding performance and mechanical properties of these CF@Ni/PI thin films have been comprehensively investigated. The study found that the nanocone-shaped Ni-plated samples exhibited superior performance. Absorption loss was dominant when a relatively low amount of Ni-plated carbon fiber was added, while reflection loss dominated when a relatively high amount was added. Adding 0.3 g of nanocone-shaped Ni carbon fiber created a 1.2 mm thin film with a shielding effectiveness of 71 dB and a tensile strength of 22.4 MPa. Additionally, the thin film demonstrated excellent flexibility and durability. Due to its exceptional mechanical properties and flexibility, this composite film holds significant potential in the fields of microelectronics and intelligent electronic devices.

Correlation between microstructure, phase composition and oxidation behavior of CoNiCrAlY/nano-Al2O3 coatings using satellited feedstock deposited by LPPS process

In this study, satellited CoNiCrAlY/2, 4 wt% nano-Al2O3, and conventional CoNiCrAlY feedstocks were deposited through the low-pressure plasma spraying (LPPS) process on Inconel738 substrate. The oxidation test was done at 1050 °C for 10 min and 5, 50, 100, 150, and 200 h. The microstructure and phase composition of the powders and coatings were characterized by the FESEM and XRD, respectively. The results showed that the CoNiCrAlY and Al2O3 powders comprised γ-CoNiCr and β-(Co,Ni)Al, and α-Al2O3, respectively. In contrast, the as-sprayed coatings included supersaturated γ-CoNiCr and meta-stable γ-Al2O3 phases. With the increase in the percentage of nanoparticles (from 2 to 4 wt%), the amount of porosity (from 2 to 3.76 vol%), and the roughness of the coating (from 6.1 to 7.5 μm) increased. With oxidation time, dissolved β-(Co,Ni)Al was recovered and then gradually consumed to create a thermally grown oxide (TGO) layer. In the composite coatings, the transformation of γ-Al2O3 to stable α-Al2O3 occurred, creating defects across the TGO layer. Therefore, with the addition of Al2O3 nanoparticles, the oxidation rate was continuously increased. The oxidation rate constant (Kp × 10−13) of conventional and composite coatings (2, 4 %) was measured as 3.89, 4.35 and 5.08 cm2.s−1, respectively.

Novel thermal conductivity and anti-corrosion coating with hydrophobic properties for heat exchanger applications

Industrial heat exchangers commonly encounter the issue of metal corrosion. Conventional anti-corrosion coatings typically exhibit poor heat conduction, leading to diminished heat exchange efficiency. This study presents a novel coating that combines high thermal conductivity with enduring anti-corrosion performance. The interfacial compatibility between the boron nitride (BN) / silicon carbide (SiC) and fluorosilicone resin (FSR) is effectively enhanced through fluorosilane modification. This improvement, in conjunction with the superior thermal conductivity of the BN/SiC composite filler and the multi-barrier effects of the two-dimensional BN material, results in the composite coating with a high thermal conductivity of 1.65 W/(m·K). After 60 days of immersion in 3.5 wt% NaCl solution, the coating maintains a low-frequency impedance exceeding 1011 Ω·cm2. Good hydrophobicity can promote the long-term anti-corrosion performance of the coating. Thanks to the inherent hydrophobicity of FSR and the reduced surface energy of the filler due to fluorosilane modification, the coating also exhibits hydrophobic characteristics, evidenced by a water contact angle of 109.69°. The development of this novel multifunctional coating holds significant implications for heat exchangers and other applications requiring a balance between thermal conductivity and anti-corrosion performance.

A smart acid-responsive GO/MS/BTA hybrid epoxy-based anti-corrosion coating for Mg alloy

Conventional surface coatings exhibit poor self-healing ability, especially under the acid corrosion conditions, which is regarded as a huge challenge for the effective protection of Mg alloy. In this study, a smart self-healing hybrid coating is facilely fabricated, providing an excellent long-term anti-corrosion performance for Mg alloys within the harsh environments. Mesoporous silica (MS) loaded with corrosion inhibitor benzotriazole (BTA) is grafted onto the surface of graphene oxide (GO), to synthesize GO-based nanomaterials, which can be uniformly dispersed in the epoxy (EP) coating through ring opening reaction and form the covalent bonds. Electrochemical Impedance Spectroscopy (EIS) results show that the modulus of the EP-GO-MS-BTA hybrid coating remains at 2.57 × 1011 Ω cm2 after immersion in 3.5 wt% NaCl solution for 15 days. In contrast to previously reported works that achieved the self-healing ability in acidity, the current EP-GO-MS-BTA coating represents an ultra-high self-healing efficiency of 1.2 × 108 Ω cm2 h−1 under acid 3.5 wt% NaCl condition (pH = 3). Due to the labyrinth effect, the impermeability of epoxy coating is enhanced by the ameliorative dispersity of GO sheet. In addition, the as-prepared GO-based nanomaterial can be used to load corrosion inhibitor BTA and possess H+ ion-responsive release property, leading to an improved corrosion protection. Combining the dual effects of superior GO dispersion and smart self-healing, it will provide a green and convenient synthetic method for constructing self-healing coatings with the excellent anticorrosion resistance.

Enhancement of corrosion resistance and bond strength in rebars employing abrasives-infused soy-protein isolate coatings

While epoxy coatings effectively prevent rebar corrosion, they can sustain damage during transportation, making them susceptible to localized corrosion during service. Additionally, these coatings can reduce the bond strength with concrete by over 20%, necessitating an increase in development length. Although soy-protein coatings could potentially repair damaged epoxy coatings in the field, they may further reduce the bond strength. This study aims to enhance the corrosion resistance of soy-protein isolate (SPI) coatings without undermining their bond with concrete. To achieve this, five new coating formulations were prepared by blending chemically inert oxide abrasives into SPI coatings in varying proportions. These modified soy-protein coatings were then assessed through physical, chemical, mechanical, and electrochemical analyses to measure their improvements. Adding abrasives beyond a certain weight proportion increased the viscosity and thickness of the coatings, improving their mechanical properties, including abrasive resistance and lap shear strength. Potentiodynamic polarization tests and macrocell analyses revealed a 94% and 78% improvement in short-term and long-term corrosion performance respectively. Moreover, when compared to conventional SPI coatings, the bond strength of the modified soy-protein coatings improved by up to 90.41%. In conclusion, SPI coatings infused with abrasives outperform traditional SPI coatings and could serve as superior secondary coats. They could even be considered as stand-alone coatings for rebars.

Advanced Analyses of Heating Elements Manufactured by an Optimized Arc Spraying Process

Heating elements in the automotive industry are currently produced by several thermal spray processes and materials. However, simpler spraying technologies such as arc spraying are investigated regarding technological suitability as a cost-effective alternative to plasma spraying in the production process of these components. Thus, several mixtures and combinations of alternative pressurizing gases and further modifications of an arc spray process were examined in this study. Consequently, coatings based on NiCr were produced, since this alloy is typical for heating elements. Coating properties were investigated by SEM, EDS, and resistivity measurements. The results demonstrate reduced oxygen content and improved morphology compared with the industrially used plasma-sprayed coatings. Additionally, the improved microstructure affects the surface quality and specific resistivity of the coatings positively. This allowed for laser texturing the arc-sprayed coatings successfully. It must be considered a drawback, though, that cracks partially appeared in the underlying coatings. In contrast, the temperature coefficients of resistance and the resistivities of the heating elements were superior to the conventional coatings, which can lay the foundation for a future industrial application. To further investigate this and to minimize the influence of potential sample preparation issues on the analysis results, different methods of cross-sectioning, i.e., in detail hot mounting, cold mounting, and ion beam polishing, were evaluated.

Novel Al2CoCrFeNi high-entropy alloy coating produced using suspension high velocity air fuel (SHVAF) spraying

Metallic coatings of Al2CoCrFeNi high entropy alloy (HEA) were deposited using the suspension high velocity air fuel spray (SHVAF) process, towards exploring its viability as a bond coat in thermal barrier coatings. The relatively high Al content promoted a BCC + B2 phase-dominated coating structure, leading to enhanced mechanical properties. The oxidized microstructure exhibited a protective Al2O3 layer with characteristics comparable to conventional bond coat alloys.

Research on Thermal Properties and High Temperature Exposure Behavior of Non-Skid Coating Fabricated by Twin Wire Arc Spraying

Conventional non-skid coatings for marine construction contain polymeric materials. These materials are generally susceptible to high temperature environments because of their low thermal conductivity and thermal resistance. A metal-based non-skid coating has great potential for high temperature applications, yet, there has only been limited research. In this study, twin wire arc spray (TWAS) was used to fabricate Al and Al-3%Ti coatings on a high strength low alloyed (HSLA) steel substrate. The purpose of this study is to confirm the feasibility of TWAS Al-based coating for non-skid areas on marine construction. The static coefficient friction of TWAS Al-based coatings exhibited excellent and uniform values compared with a conventional epoxy-based non-skid coating. The specific heat and thermal conductivity of TWAS Al-based coating was measured and compared with that of the substrate. The thermal property values of the TWAS Al-based coating were reported for the first time in this study. The TWAS Al-based coating had A continuous interface with the substrate and the general microstructural features of a thermal-sprayed metal coating. After exposure to 500℃ for 24 hours, the an Fe-Al intermetallic compound and oxide were formed inside of the coating and coating-substrate interface. The adhesion strength indicated that the TWAS Al-based coating sustained its strength after the isothermal exposure test. The Vickers hardness of the TWAS Al-3%Ti coating was higher than that of the Al coating. The solid solution hardening of Ti atoms in the as-deposited coating and the precipitation hardening of the TiAl3 compound in the heat-treated coating contributed to the improvement of in Vickers hardness. Thus, the TWAS Al-3%Ti coating is proven to be a promising nonskid coating for high temperature applications.

A latened catalytic strategy for low cure thermoset powder coating by post-dry-blending technique

Conventional thermoset powder coatings typically require curing at a high temperature of 190 °C for a minimum duration of 15 min, which poses challenges when applying them to heat-sensitive substrates and results in elevated energy costs. A solution known as low-temperature-curing powder coating (LCPC) has been developed to address this issue. By normally incorporating the curing catalyst into the coating system via hot extrusion, LCPC can achieve either a reduced curing temperature or a shortened curing period. However, the current extrusion method used for catalyst incorporation leads to undesirable side effects, such as compromised surface quality, shorter shelf-life and a narrower operational window for the hot-extrusion process involved in producing powder coatings. To overcome these challenges, a new strategy is proposed in this study, in which the tailor-made nano-catalyst is post-dry-blended into the powder coating instead of subjecting it to hot treatment with coating ingredients. This dry-blending catalyst (DBC), encapsulating nanosized fumed silica with catalysts by impregnation method, is introduced to the powder coating system before spraying, eliminating the need for hot-kneading into the powder coating system at the beginning. The DBC is attached to the surface of the particle realizing the interparticle contact mode and latening the catalysis. The dry-blended low-temperature-curing powder coating (DB-LCPC), containing a 0.03 % dosage of onium salt and 0.035 % of 2-methylimidazole, is identified as the optimum formulation due to its excellent surface quality, prominent chemical and mechanical characteristics. The sample successfully achieved low-temperature curing or a shortened curing time while maintaining excellent mechanical properties and chemical resistance. Furthermore, it exhibited superior coating appearances and a longer shelf-life compared to the hot-extruded sample. This novel DBC method has the potential to greatly enhance the adoption of low-temperature-curing powder coatings.

Effects of Synchronous Bias Mode and Duty Cycle on Microstructure and Mechanical Properties of AlTiN Coatings Deposited via HiPIMS

The good mechanical properties of metal nitrides make them ideal surface coatings for cutting tools and mold components. Conventional TiN coatings have largely been replaced by AlTiN due to their superior mechanical properties and resistance to high temperatures. In this study, we investigated the application of bias voltage to the substrate to enhance ion bombardment during the synthesis of protective AlTiN coatings using high-power impulse magnetron sputtering (HiPIMS) with synchronous trigger-direct current (ST-DC) bias voltage. The ST-DC parameters included the duty cycle duration (3%, 6%, 12%, 18%) and turn-on time, which included synchronous (TD0) or a trigger delay of 50 μs (TD50). Scanning electron microscope images revealed that the highest deposition rate (22.1 nm/min) was achieved using TD50 with a duty cycle of 3%. The results obtained using an electron probe microanalyzer and X-ray diffractometer revealed the formation of an h-AlN structure when the Al/Ti ratio was between 0.71 and 0.74. Transmission electron microscopy and nanoindentation results revealed that transforming DC bias into synchronous bias to boost the bias output time (i.e., increasing the duty cycle) increased AlTiN grain refinement (from ~100 nm to ~55 nm) with a corresponding increase in hardness (from 22.7 GPa to 24.7 GPa) as well as an increase in residual stress within the AlTiN coating (from 0.16 GPa to −51 GPa). The excellent adhesion performance of the coatings provided further evidence indicating the importance of duty cycle and trigger delay when using pulsed-DC bias in HiPIMS.

Hot corrosion resistance of Al2O3 nanoparticles reinforced CoNiCrAlY coatings deposited by LPPS and HVOF processes in molten Na2SO4-V2O5 at 850[formula omitted

In this research, satellited CoNiCrAlY/nano-Al2O3 feedstocks with 2 and 4 wt% oxide nanoparticles and conventional CoNiCrAlY powder were deposited through the HVOF and LPPS processes on Inconel 738 substrates. The hot corrosion test was done in molten Na2SO4-55wt.%V2O5 salt at 850 °C for 24 h. The microstructure and phase composition of the as-sprayed and corroded coatings were characterized by the FESEM and XRD. The results showed that by adding Al2O3 nanoparticles in the HVOF CoNiCrAlY coatings up to 4 wt%, the porosity increased from 0.6 to 2.7 vol% and the surface roughness increased from 4.4 to 7.1 μm. By adding Al2O3 nanoparticles in the LPPS CoNiCrAlY coatings up to 4 wt%, the porosity increased from 2 to 3.76 vol%, and the surface roughness increased from 6.1 to 7.5 μm. Penetration of corrosive salt in the conventional and composite HVOF coatings, including 2 and 4 wt% nanoparticles, was obtained as 72, 16, and 140 μm, respectively. Penetration of the corrosive species in the conventional and composite LPPS coatings consisting of 2 and 4 wt% nanoparticles was measured as 91, 125, and 170 μm, respectively. The hot corrosion mechanism was basic and acidic fluxing, creating (Co, Ni)2V2O7, Na(AlO2), CoCo2O4, and NiCr2O4 corrosion products.

Effects of the Mg Content on Microstructural and Corrosion Characteristics of Hot-Dip Al-Si-Mg Alloy-Coated Steel Sheets.

Hot-dip Al-Si alloy coatings with excellent resistance to corrosion and high-temperature oxidation have emerged as promising lightweight substitutes for conventional corrosion-resistant coatings. The introduction of Mg can be an effective strategy for enhancing the sacrificial protection capability of Al-Si coatings. In this study, the effects of Mg addition on the morphology, electrochemical behavior, and mechanical properties of Al-Si coatings were investigated, along with the Mg-content optimization of the coating layer. Adding Mg promoted the formation of finely distributed eutectic intermetallic phases, such as Al/Mg2Si and the primary Mg2Si phase. Notably, the Mg2Si phase coarsened significantly when ≥15 wt.% of Mg was added. In addition, an Al3Mg2 intermetallic compound was observed in coating layers containing >20 wt.% of Mg, reducing the adhesion of the coating layers. Samples containing 5-10 wt.% of Mg exhibited excellent corrosion resistance (owing to a uniform distribution of the fine eutectic Al/Mg2Si phase and the formation of stable corrosion products), whereas those containing 20 wt.% of Mg exhibited unremarkable corrosion resistance (owing to the formation of an Al3Mg2 phase that is susceptible to intergranular corrosion).