Austenitic Fe‐30Mn‐1C (FeMnC) is a prospective biodegradable implant material combining high mechanical integrity with adequate corrosion rates. The fast solidified TWIP alloy, its constituents and 316L stainless steel were electrochemically analysed in various electrolytes at 37 °C under laminar flow. Potentiodynamic polarization tests were conducted in Tris‐buffered simulated body fluid (SBF), in Tris‐buffered saline (TBS) and in 150–0.15 mM NaCl solutions (pH 7.6, 10, 5, 2) to study initial corrosion stages. Active dissolution of FeMnC is revealed in all electrolytes and is discussed on basis of the Fe and Mn behaviour plus is compared to that of 316L. The role of Tris (Tris(hydroxymethyl)aminomethane) as organic buffer for SBFs is critically assessed, particularly with view to the sensitivity of Fe. SEM studies of FeMnC corroded in NaCl revealed preferential dissolution along Mn‐rich grain boundary regions. Static immersion tests of FeMnC in SBF with surface and solution analyses (SEM/EDX, XPS, ICP‐OES) indicated that dissolution processes interfere with the formation of permeable surface coatings comprising hydroxides and salts.

Functional manganese-(Mn)-containing layers are becoming increasingly important in the fields of sacrificial corrosion protection, biodegradable medical devices or electrochemical energy conversion systems. Electrodeposition can be a low cost and time-efficient production route, but the very electronegative nature of Mn makes this reduction process quite challenging. In this paper, electrolytic potentiostatic deposition of metallic Mn layers from environmentally friendly aqueous manganese sulfate electrolytes with pH 3 is successfully demonstrated. A continuous electrolyte flow in the cathodic compartment of the electrochemical cell for controlling the pH value during deposition was found to be essential for achieving good layer qualities. Based on cyclic voltammetry analysis in combination with quartz crystal microbalance measurements a suitable deposition potential range was identified. The obtained electrodeposited layers were characterized by means of SEM, XRD, GD-OES and XPS. The shift of the deposition potential from −2.4 VMSE to −2.6 VMSE (deposition time 60 min) yields a thickness increase of the metallic α-Mn deposits from< 500 nm to ~2 μm. Only thin additional surface regions of Mn-oxides/-hydroxides were identified. The important role of (NH4)2SO4 as complex-forming electrolyte additive is discussed and an impact of the salt concentration on the deposit properties is revealed. This is a promising starting point for further Mn alloy deposition analysis.

Sputtering and electrodeposition are among the most widespread techniques for metallic thin film deposition. Since these techniques operate under different principles, the resulting films typically show different microstructures even when the chemical composition is kept fixed. In this work, films of Fe 70 Pd 30 were produced in a thickness range between 30 and 600 nm, using both electrodeposition and sputtering. The electrodeposited films were deposited under potentiostatic regime from an ammonia sulfosalicylic acid-based aqueous solution. Meanwhile, the sputtered films were deposited from a composite target in radio frequency regime. Both approaches were proven to yield high quality and homogenous films. However, their crystallographic structure was different. Although all films were polycrystalline and Fe and Pd formed a solid solution with a body-centered cubic structure, a palladium hydride phase was additionally detected in the electrodeposited films. The occurrence of this phase induced internal stress in the films, thereby influencing their magnetic properties. In particular, the thickest electrodeposited Fe 70 Pd 30 films showed out-of-plane magnetic anisotropy, whereas the magnetization easy axis lied in the film plane for all the sputtered films. The domain pattern of the electrodeposited films was investigated by magnetic force microscopy. Finally, nanoindentation studies highlighted the high quality of both the sputtered and electrodeposited films, the former exhibiting higher reduced Young's modulus and Berkovich hardness values.

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