The Surface Properties of Implant Materials by Deposition of High-Entropy Alloys (HEAs)

High-entropy alloys (HEAs) contain more than five alloying elements in a composition range of 5-35% and with slight atomic size variation. Recent narrative studies on HEA thin films and their synthesis through deposition techniques such as sputtering have highlighted the need for determining the corrosion behaviors of such alloys used as biomaterials, for example, in implants. Coatings composed of biocompatible elements such as titanium, cobalt, chrome, nickel, and molybdenum at the nominal composition of Co30Cr20Ni20Mo20Ti10 were synthesized by means of high-vacuum radiofrequency magnetron (HVRF) sputtering. In scanning electron microscopy (SEM) analysis, the coating samples deposited with higher ion densities were thicker than those deposited with lower ion densities (thin films). The X-ray diffraction (XRD) results of the thin films heat treated at higher temperatures, i.e., 600 and 800 degrees C, revealed a low degree of crystallinity. In thicker coatings and samples without heat treatment, the XRD peaks were amorphous. The samples coated at lower ion densities, i.e., 20 mu Acm(-2), and not subjected to heat treatment yielded superior results in terms of corrosion and biocompatibility among all the samples. Heat treatment at higher temperatures led to alloy oxidation, thus compromising the corrosion property of the deposited coatings.

Automated summary

High-entropy alloys (HEAs) with more than five alloying elements and slight atomic size variation are being studied for their corrosion behaviors as biomaterials, particularly in implants. Coatings composed of biocompatible elements were synthesized using high-vacuum radiofrequency magnetron (HVRF) sputtering. Coating thickness was influenced by ion densities, while heat treatment temperatures affected crystallinity. Samples coated at lower ion densities and without heat treatment showed superior corrosion and biocompatibility.