In this work, sulfonated polyetheretherketone (S-PEEK)-based coatings, nanocrystalline ZnS and hydroxyapatite (n-HA) particles were developed on Zr-2.5Nb zirconium alloy substrates by electrophoretic deposition (EPD) combined with subsequent heat treatment. The properties of suspensions and deposition kinetics were studied. Cationic chitosan polyelectrolyte ensured the stabilization of the suspension and allowed for the co-deposition of all coating components on the cathode. The heating of the coated samples at a temperature of 450 °C and slow cooling resulted in sulfonation of the PEEK and the formation of dense coatings. The coatings were characterized by high roughness, hardness, modulus of elasticity and adhesion strength. The coatings revealed mild hydrophilicity, improved the electrochemical corrosion resistance of the alloy and induced the formation of hydroxyapatite with a cauliflower-like morphology on its surface during the Kokubo test. This work explored the great development potential of advanced sulfonated PEEK-based coatings, incorporating antibacterial and bioactive components by EPD combined with heat treatment to stimulate the surface properties of zirconium alloy for prospective dental and orthopedic applications. The antibacterial and osteoconductive properties of the obtained coatings should be further investigated.

In this study, multilayered Cu/HA/ZnS + PEEK coatings were fabricated using hybrid technology on Zr–2.5Nb alloy substrates. The use of electrophoretic deposition (EPD) and heat treatment allowed the 1st base composite ZnS + PEEK layer and the 2nd hydroxyapatite (HA) top layer to be obtained. The EPD kinetics of both layers was studied. Heating at a temperature of 450 °C and slow cooling resulted in densification and sulfonation of PEEK. It also led to an increase in the adhesion of HA particles on the surface of the PEEK + ZnS layer and to the settlement of HA particles deep into the 1st layer. The effect of substrate preparation on the adhesion strength of coatings was investigated. The ZnS + PEEK layer exhibited high adhesion to the chemically treated zirconium alloy. Furthermore, the first layer was characterized by a high scratch resistance. The selective distribution of Cu on the top of the coating was obtained by shadow-masked pulsed laser deposition (PLD). The multilayered coatings exhibited high roughness and mild hydrophobicity. This study showed the possibility of obtaining a multilayered coating system with a controlled distribution of bioactive components (HA) and antimicrobial components (Cu) on its surface using a hybrid method that combined EPD, heat treatment, and PLD.

Ferrosilicon (FeSi) is a commercially important material with multiple uses in metallurgical processes. Recently, in an attempt to reduce the carbon impact of the FeSi production process, researchers have proposed using recycled Si recovered from electronic waste in the production of FeSi. However, Si recovered from electronic waste usually contains Al, Cu, and Sn as impurities. Hence, FeSi alloys produced with recycled Si from electronic waste may contain all these elements in varying proportions. Al, Cu, and Sn have been explored as alloying elements to produce alloys with Fe. FeSiAl alloys have also been studied recently for their superior properties. In this work, a multicomponent FeSiAlCuSn alloy is produced, and the phases formed at different temperatures are analyzed using different phase identification techniques. We also analyze the hardness of the multicomponent alloy to find any deviation from the standard FeSi alloy without the additional alloying elements. Understanding the phases and the composition of such alloys may help design future multi-component or high-entropy alloys involving Fe, Si, Al, Cu, and Sn for specific applications.