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.

Electroplating is a key process in many industrial fields such as automotive, electronics and decorative applications; this process makes it possible to provide new properties to substrates materials such as corrosion resistance, hardness and aesthetic value. Nonetheless, electroplating is considered one of the most non-sustainable industries related to the manufacturing sector, from both an environmental and a social point of view. With the approaching deadlines set by the United Nations for the 2030 Agenda, electroplating companies have started a trend of innovating their production processes with a focus on sustainability, acting on several fronts: performing simulations to predict criticalities and optimize working procedures, reducing the material used and recovering it from processing water. The purpose of this communication is to highlight the state of the art of sustainable practices peculiar to the electroplating industry, critically analyzing ongoing challenges to achieve and exceed the targets set by regulatory agencies. Both atomistic and multiphysics simulations will be analyzed as powerful tools to design both new sustainable formulations and items; then, the problem of metal dispersion will be discussed, evaluating different industrial approaches; finally, the focus will be shifted towards the general procedures to recover metal from wastewater.

A method for the determination of the intermetallic diffusion coefficient in the Cu-Au system is described based on energy dispersive X-ray techniques. XRF and EDS analysis were used to measure the thickness of the electroplated gold coating and the copper diffused through it, respectively. This information was used to obtain the diffusion coefficient through an equation based on Fick's law. Colour measurements and metallographic section analysis of the samples were also performed to evaluate alternative methods for a qualitative determination of diffusion rate. The thickness of the gold layer was chosen in agreement with what is used in decorative and functional applications (<1 μm). The measurements were performed on samples heated in a range of temperatures between 100 °C and 200 °C from 12 to 96 h. The results obtained follow a linear trend between the logarithm of the diffusion coefficient and the inverse of the temperature and are in line with the values found in the literature.

Barrier layers against intermetallic diffusion are a fundamental part on engineering electroplated coatings as they improve the lifetime of goods reducing wastes and improving the sustainability of the production chain. This study aims to set a cost-effective methodology to characterize barrier systems by evaluating the effectiveness with a recent approach based on XRF and EDS and characterize the kinetic of diffusion processes with X-ray diffractometry. Several high fashion barrier systems were tested highlighting that anticorrosion systems are not automatically suited as barrier layers for intermetallic diffusion, as opposed to industrial practice. Investigations on gold coatings obtained varying the current density revealed a correlation between the activation energy of the diffusion process, roughness, and crystallite size.