This research focused on comparison of adhesion properties of three different primers for wide consumption. Tested primers differed in their price range, and the conducted experiment aimed to ...determine whether more expensive primers were providing better adhesion between the substrate material and the coating. The primers were applied on specimens in two layers, each being 30 μm thick (total dry film thickness was 60 μm), as well as in one layer being 45 μm thick. After drying, specimens were exposed to indoor and outdoor atmospheric conditions. Adhesion properties were tested by the cross-cut test, and analysis of obtained results proved that the primers’ price range cannot be considered as an indicator of the primers’ quality with respect to their adhesion properties.
Conversion layers produced on an industrial scale are typically based on phosphates or chromates and involve toxicological and environmental problematic treatment solutions and waste. Concerning this ...matter, layered double hydroxide (LDH)‐based conversion layers prepared by the process described in our study offer a promising alternative where the treatment solution comes with no environmental or toxicological concerns. The corrosion protection of Zn–Al–Mg (ZM)‐coated steel by an in situ grown LDH conversion layer is investigated by potentiodynamic polarization measurements, linear polarization resistance determination, neutral salt spray test and mass loss test. An LDH layer formation time as short as 30 s considerably improves the corrosion resistance of ZM‐coated steel in electrochemical testing as well as in industrially relevant corrosion testing under chloride‐containing atmospheres. With prolonged LDH formation times, further improvement in corrosion protection is obtained. The significantly increased corrosion resistance of ZM‐coated steel after the industrially feasible treatment time of 30 s makes LDH‐based conversion layers a promising candidate for novel industrially viable conversion layers, with enhanced corrosion performance and environmentally benign as well as sustainable chemistry.
This study investigates the potential of layered double hydroxide (LDH) conversion layers synthesized by an environmental and toxicological uncritical process to increase the corrosion resistance of Zn–Al–Mg (ZM) coated steel. LDH layers prepared within industrial feasible reaction times as short as 30 s significantly decrease the corrosion rate of the ZM coating under chloride‐containing conditions and therefore considerably delay the appearance of red rust.
Inkjet-printing technology enables the contactless deposition of functional materials such as conductive inks on surfaces, hence reducing contamination and the risk of substrate damage. In printed ...electronics, inkjet technology offers the significant advantage of controlling the volume of material deposited, and therefore the fine-tuning of the printed geometry, which is crucial for the performance of the final printed electronics. Inkjet printing of functional inks can be used to produce sensors to detect failure of mechanical structures such as carbon fiber reinforced composite (CFRC) components, instead of using attached sensors, which are subject to delamination. Here, silver nanoparticle-based strain sensors were embedded directly in an insulated carbon-fiber laminate by using inkjet printing to achieve an optimized conductive and adhesive geometry, forming a piezoresistive strain sensor. Following the inkjet-printing optimization process, the sensor conductivity and adhesion performance were evaluated. Finally, the sensor was quantified by using a bending rig which applied a pre-determined strain, with the response indicating an accurate sensitivity as the resistance increased with an increased strain. The ability to embed the sensor directly on the CFRC prevents the use of interfacial adhesives which is the main source of failure due to delamination.
Our study focuses on the use of a remote atmospheric pressure plasma process for the improvement of polymer surface reactivity. Indeed, surface activation of carbon-fiber-reinforced polymers that use ...a polyetheretherketone matrix is required to achieve strong and long-term adhesion of paint on the composite. Emphasis will be placed on the contribution of gas plasma used on surface modification. We use two techniques to characterize adherence improvement: a qualitative and industrial approach with a cross-cut test and a quantitative approach with a three-point bending test. However, to provide a better understanding of the plasma-induced modifications using air or nitrogen gas, diagnostics of the surface are also necessary. The wettability improvement, chemical surface modifications, and topography are analyzed by using contact angle measurement, X-ray photoelectron spectroscopy, and atomic force microscopy, respectively. The combination of these diagnostics highlights the capability of plasma treatment to tune the plasma/surface interactions depending on gas plasma, which results in improved adhesion.
•An atmospheric pressure plasma process is used to activate a carbon-fiber-reinforced polymer (PEEK) and improve adhesion.•Air plasma has been shown to be relatively aggressive inducing surface oxidation.•Nitrogen plasma led to a smoother treatment with typical nanopeak formation.•Contribution of an unusual adhesion test has been shown to be relevant in differentiation between the various adherence.
In this work, formulations of "environmentally compatible" silicone-based antifouling, synthesized in the laboratory and based on copper and silver on silica/titania oxides, have been characterized. ...These formulations are capable of replacing the non-ecological antifouling paints currently available on the market. The texture properties and the morphological analysis of these powders with an antifouling action indicate that their activity is linked to the nanometric size of the particles and to the homogeneous dispersion of the metal on the substrate. The presence of two metal species on the same support limits the formation of nanometric species and, therefore, the formation of homogeneous compounds. The presence of the antifouling filler, specifically the one based on titania (TiO
) and silver (Ag), facilitates the achievement of a higher degree of cross-linking of the resin, and therefore, a better compactness and completeness of the coating than that attained with the pure resin. Thus, a high degree of adhesion to the tie-coat and, consequently, to the steel support used for the construction of the boats was achieved in the presence of the silver-titania antifouling.
The paper focuses on the cross-cut test, which serves as a basis for determining the adhesion test on the surface of aluminium parts. The coating adhesion test was performed according to the ISO 2409 ...standard where. Before carrying out the actual measurement, the tools necessary for making those individual measurements were prepared. A knife, an adhesive tape and a grid were used. The result was evaluated on the basis of the ISO 2409 standard. Spacing of a grid was 2mm apart. Grid exam cut test was carried out on 32 samples. The classification of the samples ranged from 0 to 1. At 1, we found that the surface of the material was slightly damaged. At the scale of 0, a smooth cut was made on the material surface, and no damage occurred. Through research, we found that with a constant chemical degreasing factor, the adhesion test varies according to the EN ISO 2409 standard at values 0 and 1. It follows that if we wanted to achieve worse cutting conditions in the grid, we would have to change the temperature of the solution, the time depositions.
Ionized sputtering like high power impulse magnetron sputtering HIPIMS opens new horizons for cost effective, environmental friendly plastic metallization with excellent adhesion. First reports on ...HIPIMS deposited films on polymer foils, textiles, and different untreated plastics showed significant adhesion improvement of the metallic or oxide coatings applied. Plexiglas (PMMA) is a very attractive substrate material due to its properties for several commercial applications. Since PMMA is very sensitive to the UV radiation of technical plasmas, direct metallization of the surface by sputtering is conventionally not possible. Using ionized sputtering it is shown that the adhesion can be enhanced to excellent level, passing a combined cross cut and tape test without any failure. The study of the interface correlated to the different peak current densities of the HIPIMS processes shows some trends for the significant adhesion improvement. With increasing peak current in the HIPIMS discharge, i.e. increasing degree of ionized species forming the film, the adhesion is significantly improved. The failure mechanism changes from adhesive failure and poor adhesion to a cohesive failure and excellent adhesion. Furthermore, the surface of the polymer was modified as a result of the increasing ionization. The PMMA surface reorganizes and roughens due to ions forming the film and additionally electrons providing local thermal annealing by recombination.
•HIPIMS for direct metallization of PMMA•Excellent adhesion without any pretreatment•Influence of peak current on adhesion•Coating-substrate interface investigations
The silicate conversion coating was modified with nano-silica and applied on the surface of AA2024 by dip-coating technique. The mechanical properties of produced modified silicate layer were ...investigated by the pencil scratch hardness, cross-cut and abrasion resistance tests. The characterisation of coated surface before and after the tests was studied with optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy and atomic force microscopy. Addition of nano-silica to the silicate coating caused an enhancement in the SiO
2
:K
2
O ratio. The results showed that the homogeneity of coating surfaces increased in the presence of nano-silica. The wear and scratch resistance of the modified silicate layer improved against the sliding conditions. In addition, the adhesion of coating layer to the substrate metal increased.
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