Electrodeposition of amorphous Fe-Cr-Ni stainless steel alloy with high corrosion resistance, low cytotoxicity and soft magnetic properties

Abstract

Electrodeposition of Fe-Cr-Ni alloy thin films with high corrosion resistance, low cytotoxicity and soft-magnetic properties is reported. Fe-Cr-Ni films with Cr contents from 5 wt% to 40 wt% were prepared by adjusting the current density during electrodeposition and the film properties were investigated. An excellent corrosion resistance was found in films with high Cr contents (≥30 wt%), where anodic polarization performance similar to those of AISI 304 and 316L stainless steels was observed in both acidic and biological media. Cell compatibility, measured by lactate dehydrogenase assay, demonstrated that electrodeposited Fe-Cr-Ni films exhibit low cytotoxicity, comparable to AISI 304 and 316L stainless steels. Unlike AISI 304 and AISI 316L, which are conventional austenite stainless steels, the electrodeposited Fe-Cr-Ni films were found to be amorphous. This leads to soft ferromagnetic characteristics, which are dependent on the alloy composition. The unique combination of excellent corrosion resistance, low cytotoxicity and tunable magnetic properties makes this material interesting for functional coatings and components in advanced biological and medical microsystems.

‘Green’ Cr(iii)–glycine electrolyte for the production of FeCrNi coatings: electrodeposition mechanisms and role of by-products in terms of coating composition and microstructure

“…1a). As reported in previous similar works, 26,30 the presence of cracks is mainly dependant on the thickness of the lm (crack-free samples obtained when coating thickness is less than 5 mm). However, crack-free coatings (thickness # 5 mm) started to crack immediately or a few days aer deposition, when the Cr content in the coating exceeded a certain amount (Cr $ 28 wt%).…”

“…It could be expected that the higher amount of Ni (see Section 3.1.3) in the Ni anode samples would cause g-Fe to be the predominant phase in the electrodeposited lms (nickel retains austenitic phase in stainless steel 27 ). However, from one of our previous studies, 30 the microstructure of FeCrNi lms was found not to be inuenced by Cr and Ni concentrations. Therefore, the microstructure diversity is anode-dependant and most probably related to impurity variations.…”

“…The FeCrNi electrodeposits present nodule-like features, which are undistinguishable in terms of composition with respect to the smooth surface, as observed in our previous work. 30 Nevertheless, the difference in anode material does not particularly affect the surface morphology of the studied coatings.…”

Electrodeposition of Thick and Crack-Free Fe-Cr-Ni Coatings from a Cr (III) Electrolyte

“…As a result, more NaCl solution reaches the substrate material (copper) and an increased cathodic reaction takes place on the nobler copper, which shifts the corrosion current potential towards positive values. The difference in electrochemical behavior between the electrodeposited Fe-Cr-Ni samples and the AISI 304 stainless steel is attributed to the dissimilarities in the microstructure and chemical composition of the passive oxide film [26]. As previously shown in the study on the influence of heat treatment on the microstructure of Fe-Cr-Ni coatings, electrodeposited Fe-Cr-Ni alloys are amorphous or nanocrystalline in contrast to its metallurgical crystalline counterpart [11].…”

Investigation of Mg–xLi–Zn alloys for potential application of biodegradable bone implant materials

“…[7][8][9]. However, recent researches find that there are some disadvantages in these implants: The toxic ions, Ni and Cr ions released from stainless steel, as well as Al released from titanium alloy, which will cause irreversible damage if absorbed excessively by the human body [10][11][12]; The elastic modulus of these bone implants is too much higher than that of natural bone, which can not avoid stress shielding effect [13,14]; These implants can not degrade completely by themselves, and they need to be taken out again after bone healing [15]. Therefore, it has become the focus of orthopedic clinic to find a suitable medical metal which releases no toxic ions, produce no stress shielding, and degrade at the same time.…”