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... chromium coatings on polymer substrates incorporate numerous steps of chemical baths and rinses to produce the 35 to 50 microns of leveling and support metals under the final, thin, decorative chromium top layer (Figure 1). These steps include: cleaning, conditioning, neutralizing, acid etching, catalyzing, accelerating, nickel flash, copper plating, nickel plating, chrome plating along with the necessary effluent care and disposal. ...
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... pictures of the SuperChrome™ chrome coated plaques and electroplated chrome coated plaques are shown below in Figures 9 -12: Destructive tests were performed to compare the mechanical behavior of electroplated chromium and PVD chromium. These tests include scratch at various loads using an Erichsen Model 413 tester ( Figure 13) with a 90 µm diameter diamond tip stylus (Figure14), and 10 kg load Braille C diamond indentation on the coated ABS plaques (Figures 15 -17). Table 2 contains micrographs of the various scratch tests and profilometer scans across the scratches. ...
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... pictures of the SuperChrome™ chrome coated plaques and electroplated chrome coated plaques are shown below in Figures 9 -12: Destructive tests were performed to compare the mechanical behavior of electroplated chromium and PVD chromium. These tests include scratch at various loads using an Erichsen Model 413 tester ( Figure 13) with a 90 µm diameter diamond tip stylus (Figure14), and 10 kg load Braille C diamond indentation on the coated ABS plaques (Figures 15 -17). Table 2 contains micrographs of the various scratch tests and profilometer scans across the scratches. ...
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... 50.0 µm thick electroplated Cr sample in figure 15 has the smallest diameter crater, and like the SuperChrome™ sample in figure 16, shows excellent adhesion. Stress cracking and adhesion loss of the sample in Figure 17, is mostly due to the tensile stress cracking and hardness of the single layer chrome coating. ...
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... 50.0 µm thick electroplated Cr sample in figure 15 has the smallest diameter crater, and like the SuperChrome™ sample in figure 16, shows excellent adhesion. Stress cracking and adhesion loss of the sample in Figure 17, is mostly due to the tensile stress cracking and hardness of the single layer chrome coating. ...
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... 50.0 µm thick electroplated Cr sample in figure 15 has the smallest diameter crater, and like the SuperChrome™ sample in figure 16, shows excellent adhesion. Stress cracking and adhesion loss of the sample in Figure 17, is mostly due to the tensile stress cracking and hardness of the single layer chrome coating. ...
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Electroplated hard chromium (EPHC) has been widely used in industry due to its excellent mechanical properties, but the development of this technology is limited by environmental risks. The physical vapor deposition (PVD) process has shown promise as an alternative to EPHC for producing chromium-based coatings. In this research, we investigate the...
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... From the literature, Cr coatings were deposited on polymers in a thickness range between~100 nm and~600 nm [3,15,18]. Thicker films (>1000 nm) are often desired, especially for decorative applications, since they show higher impact abrasion resistance-however, there is a trade-off, since increasing the thickness of the metallic films may increase the propensity for coating delamination [19]. In the case of functional coatings, the occurrence of cracking or delamination due to excessive residual stress levels can dramatically affect the performance, reliability, and durability of material components [20]. ...
... For the successive use of these coatings in the automobile industry, it is a prime factor that the coatings must be free of defects and at the same time possess high thickness. As the thickness increases, the films have greater abrasive resistance, but there is also a higher chance of cracking the coating [19]. Figure 2 shows the plain-view SEM images of polymeric substrates coated with the following thicknesses: 800 nm, 1400 nm, and 1600 nm. ...
... 16 For the successive use of these coatings in the automobile industry, it is a prime factor that the coatings must be free of defects and at the same time possess high thickness. As the thickness increases, the films have greater abrasive resistance, but there is also a higher chance of cracking the coating [19]. Figure 2 shows the plain-view SEM images of polymeric substrates coated with the following thicknesses: 800 nm, 1400 nm, and 1600 nm. ...
Metal-coated plastic parts are replacing traditional metallic materials in the automotive industry. Sputtering is an alternative technology that is more environmentally friendly than electrolytic coatings. Most metalized plastic parts are coated with a thin metal layer (~100–200 nm). In this work, the challenge is to achieve thicker films without cracking or without other defects, such as pinholes or pores. Chromium coatings with different thicknesses were deposited onto two different substrates, polycarbonate with and without a base coat, using dc magnetron sputtering in an atmosphere of Ar. Firstly, in order to improve the coating adhesion on the polymer surface, a plasma etching treatment was applied. The coatings were characterized for a wide thickness range from 800 nm to 1600 nm. As the thickness of the coatings increased, there was an increase in the specular reflectivity and roughness of the coatings and changes in morphology due to the columnar growth of the film and a progressive increase in thermal stresses. Furthermore, a decrease in the hardness and the number of pinholes was noticed. The maximum thickness achieved without forming buckling defects was 1400 nm. The tape tests confirmed that every deposited coating showed a good interface adhesion to both polymers.
... Base coat is the layer of material which demonstrates higher interfacial adhesion to polymeric substrate and serve as an intermediate layer between the substrate and final metallic coating. Vergason [53] deposited Cr films on an ABS substrate using magnetron sputtering rather than electroless plating. After selecting the proper base coat and optimizing the deposition process, the coating performance was similar to that of the well-established Cr-electroplated components regularly used in the decorative sector of the automotive industry. ...
... Decorative coatings (glassware, trophies, and medallions) [53,65] Optical coatings (lenses and headlamps) [73] Electrical devices (capacitors, solar cells, electromagnetic interference shielding, and data storage) [50,70] Materials with improved mechanical and wear properties [59,74] Biomedical applications (biocompatibility and antibacterial activities) [56,61]. ...
... Metallic decorations to improve the appearances of plastic parts are often performed using a PVD technique. Polymers such as ABS are typically metalized with a Cr coating via eco-unfriendly electro-chemical plating [53], thus PVD is a promising alternative approach for preparing a thin conductive layer of Cr or Al [46]. When a reactive gas (such as an N-or C-containing gas) is added to the PVD process, PVD can also achieve compound films (e.g., TiN, TiCN, or CrN) with various colors, which is a distinct advantage in decorative applications. ...
Polymers and their composites are widely used for designing structures in aerospace, automotive, electronic, sport industries due to their lightweight, cost, and processing advantages. However, the surface of polymeric materials typically exhibits intrinsic deficiencies, limiting their durability and functionalities, e.g., low wear resistance, low thermal and electrical conductivity, low adhesion, low bioactivity, low reflectiveness, and weak photochemical resistance. Polymer metallization is an emerging concept that addresses these deficiencies by forming a metallic skin on polymeric surfaces. Herein, the working principles, recent advances, challenges, functional capabilities, and applications of the state-of-the-art polymer metallization methods in the fields of additive manufacturing, coating technologies, and material science are reviewed on nano-, micro-, and macroscales. The polymer metallization methods applied to polymeric and polymer composite substrates are physical vapor deposition, electrochemical plating, a family of thermal spray methods (such as flame spaying, arc spraying, plasma spraying, and cold spraying), and a series of polymer–metal direct bonding methods (such as adhesive bonding, injection overmolding, and fusion joining techniques, including ultrasonic joining, friction spot joining, electromagnetic induction joining, and laser joining). Understanding the key aspects within these approaches would guide scientist and engineers for optimizing the design and durability of structural materials made of polymers/composites.
... Due to problems previously identified using Cr-VI in electrodeposition processes, the REACH program (Regulation for Registration, Evaluation, Authorisation and Restriction of Chemicals) developed at the European Union has as its focus the abolishment of this process for the deposition of decorative Cr coatings. Thus, Vergason et al. [34] investigated the properties of Cr deposited by DC sputtering with a view to its application in the automotive industry. Subsequent evaluations carried out by several OEMs in the automotive industry confirmed that the investments obtained in vacuum had a nanoscale, in contrast to the thickness traditionally obtained by electroplating, presenting extremely interesting characteristics for the applications in question. ...
The automotive industry is a pioneer in solutions that meet market expectations. However, in the automotive industry, some less environmentally friendly technologies are still used, such as electroplating. Due to legislative restrictions in several countries, thin coatings made in a vacuum have been replacing coatings traditionally made by electroplating, mainly in decorative terms. This work is more focused on the use of these coatings made in vacuum for optical applications, namely on headlights and exterior backlit components. Although these components are protected during the period of use, there may be situations of contact during the assembly of the components or their repair, necessary to safeguard and to ensure that these coatings have the scratch and wear resistance needed to withstand any treatment deficiency during the operations referred to above. Therefore, this work is essentially focused on the study of the wear resistance of Cr coatings made by PVD (Physical Vapour Deposition) on polymeric substrates. To this end, the coatings previously studied have now been subjected to micro-abrasion tests, with a view to assessing their wear resistance. For this purpose, alumina abrasive has been used, and the wear mechanisms observed in the coatings were studied. The abrasion and scratch tests showed that the most stable film has the one provided with 10-layers, showing greater wear resistance as well, greater adhesion to the substrate and less cohesive failures in the performed tests. Given the nature of the substrate and the coating, the results obtained are very promising, showing that these 10-layer Cr thin coatings can overcome any careless operation during manufacturing, assembly and repair processes, when applied in lightning or backlit components in motor vehicles.
... Much effort has been invested over the decades to develop alternatives to replace the toxic chrome electroplating process. Environmentally-safe physical vapor depositions (PVD) can provide a simple yet reliable chromium coating [2][3][4][5]. In addition to being the protective and decorative top-coat layer, chromium layers can also be used as the adhesion enhancement interlayer for nitride and carbide coatings [6,7]. ...
Environmentally-safe high-power impulse magnetron sputtering (HiPIMS) technology was utilized to deposit chromium films. This research focused on the influences of the HiPIMS pulse widths on the microstructure of films deposited at different deposition pressures and substrate bias voltages. Under the conditions of the same average HiPIMS power and duty cycle, the deposition rate of the Cr thin film at working pressure 0.8 Pa is slightly higher than at 1.2 Pa. Also, the difference between deposition rates under two pressures decreases with the discharge pulse width. The deposition rate of the short pulse width 60 μs is lowest, but those of 200 and 360 μs are approximately the same. With no or small direct current substrate biasing, the microstructure of films coated at short pulse width is similar to the typical magnetron sputtering deposited films. Elongating the pulse width enhances the ion flux toward the substrate and changes the film structure from individual prism-like columns into tangled 3-point/4-point star columns. Substantial synchronized substrate biasing and longer pulse width changes the preferred orientation of Cr films from Cr (110) to Cr (200) and Cr (211). The films deposited at longer pulse width exhibit a higher hardness due to the reducing of intercolumn voids.
Physical Vapor Deposition (PVD) is a widely utilized process in various industrial applications , serving as a protective and hard coating. However, its presence in fields like fashion has only recently emerged, as electroplating processes had previously dominated this reality. The future looks toward the replacement of the most hazardous and toxic electrochemical processes, especially those involving Cr(VI) and cyanide galvanic baths, which have been restricted by the European Union. Unfortunately, a complete substitution with PVD coatings is not feasible. Currently, the combination of both techniques is employed to achieve new aesthetic features, including a broader color range and diverse textures, rendering de facto PVD of primary interest for the decorative field and the fashion industry. This review aims to outline the guidelines for decorative industries regarding PVD processes and emphasize the recent advancements, quality control procedures, and limitations.
PVD (physical vapor deposition) and CVD (chemical vapor deposition) have gained greater significance in the last two decades with the mandatory shift from electrodeposition processes to clean deposition processes due to environmental, public safety, and health concerns. Due to the frequent use of coatings in several industrial sectors, the importance of studying the chromium coating processes through PVD–sputtering can be realized, investing in a real alternative to electroplated hexavalent chromium, usually denominated by chromium 6, regularly applied in electrodeposition processes of optical products in the automotive industry. At an early stage, experimental tests were carried out to understand which parameters are most suitable for obtaining chromium coatings with optical properties. To study the coating in a broad way, thickness and roughness analysis of the coatings obtained using SEM and AFM, adhesion analyzes with the scratch-test and transmittance by spectrophotometry were carried out. It was possible to determine that the roughness and transmittance decreased with the increase in the number of layers, the thickness of the coating increased linearly, and the adhesion and resistance to climatic tests remained positive throughout the study. Thus, this study allows for the understanding that thin multilayered Cr coatings can be applied successfully to polymeric substrates regarding optical applications in the automotive industry.
