A. Maciej

Electrodeposition of Zinc Coatings from Ionic Liquid

The electrochemical deposition of zinc coatings from 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) baths on steel substrate was described in this paper. The influence of [ZnCl2]/[BMIMCl] ratio, current density as well as temperature have been investigated. It was found that electrodeposition in all of tested baths and parameters allowed to obtain zinc coatings. The surface of coatings were matte and in the most of cases the coating morphology was not homogenous. On the basis of corrosion investigation it was pointed out that application of the baths of higher ZnCl2 content are more beneficial for zinc coatings electrodeposition that the one of [ZnCl2]/[BMIMCl]= 2:3.

Effects of Sn and Mo Contents on the Electrochemical Behavior of Biomedical Ti-Mo-Sn Alloys Prepared in the Powder Metallurgy Process

The aim of this study was to investigate the effects of Sn and Mo contents on electrochemical behavior and phase analysis of Ti12Mo23Sn (wt.%) and Ti23Mo12Sn (wt.%) alloys for biomedical applications. The samples were manufactured by blended combining the elemental method from a sequence of uniaxial and cold isostatic pressing with subsequent densification by sintering at 1000°C, in protective gas atmosphere. The corrosion resistance of the studied alloys in Ringers solution were determined. The structural properties were examined by scanning electron microscopy (SEM + EDS) and X-ray diffraction (XRD). X-ray phase analysis shows two phases: β-Ti and Ti3Sn for both samples. The proposed quantitative composition of the tested samples was confirmed in the chemical analysis. The results of the electrochemical analysis reveal that the open circuit potentials recorded for the Ti12Mo23Sn and Ti23Mo12Sn samples were quite similar. Moreover, obtained results indicate that the titanium alloy composed of 23 wt.% of Mo and 13 wt.% of Sn exhibited slightly better corrosion resistance than the Ti12Mo23Sn sample with lower concentration of Mo (12 wt%) in the Ringer`s solution.

Galvanic Formation of Zn-Ni/Zn-Co Type Multilayer Alloy Coatings on Steel Substrate

Zn-Ni and Zn-Co monolayer and Zn-Ni/Zn-Co multilayer (from 2 to 128 layers) alloy coatings were formed on steel substrate by electrodeposition from acidic Zn-Ni bath and neutral Zn-Co bath. Samples were tested in salt chamber for corrosion resistance in neutral salt spray. Open circuit potential measurement and gravimetric study of corrosion were carried for samples immersed in the 5% NaCl solution.It was found that coatings of Zn-Ni surface layer occurred higher corrosion resistance then the coatings of Zn-Co surface layer. Sixteen-layer coating with Zn-Ni surface layer proved to be most effective in protecting the steel substrate. Zn-Ni monolayer showed the lowest corrosion potential, which affects the corrosion properties. Sample weight changes during exposure to a corrosive environment are related to digestion of the coating and the formation of corrosion products.

Anodic Treatment of Zn-Ni Alloy in Alkaline Solutions

The investigations on anodic oxidation of galvanic Zn-Ni alloy coating in the baths containing sodium hydroxide, sodium silicate and ammonium pentaborate was described in this paper. The surface morphology studies (SEM) and corrosion characterization was the main part of the work. It was found that the anodic treatment of the Zn-Ni alloy coating in the alkali solutions basis on NaOH permit to the obtaining the oxide layer with cracks formation. Application of the baths containing also sodium silicate and ammonium pentaborate cause the cracks decay. The corrosion studies may indicate that the cracks are shallow.

Corrosion Study of Amorphous Mg67Zn29Ca4 Alloy

The aim of this paper was investigating the corrosion resistance of Mg67Zn29Ca4 metallic glass and evaluating the ability of use studied amorphous alloy for medical applications as biodegradable implants. For comparative purposes the corrosion studies of the amorphous Mg67Zn29Ca4 samples were performed in a few simulated body fluids at 37°C. The immersion tests were performed in Ringer’s solution, PWE (multielectrolyte physiological fluid) and 3%NaCl water solution. The amount of evolved hydrogen[ml/cm2] and a corrosion rate Vcorr [g/(day·m2)] of studied Mg67Zn29Ca4 alloy were compared. Surface morphology of metallic glass after corrosion study was performed using the scanning electron microscopy.In aim determination dissolution rate and amount of evolved hydrogen was simulated the environment of human body fluids during immersion tests. The work presents structure characterization and corrosion properties analysis of Mg67Zn29Ca4 bulk metallic glasses in the form of plates. Samples structure was analyzed by means of X-ray diffraction. Fractographic study a cross section of the sample in plates form was performed using scanning electron microscopy

Microplasma Oxidation of Magnesium Alloy AZ91D by Impulse Current

In this work the results of investigations on thickness distribution of conversion coatings on magnesium alloy AZ91D obtained by plasma electrolytic oxidation (PEO) in sodium silicate solution are presented. The morphology and chemical composition as well as thickness distribution of obtained coatings, with special respect to hard to reach points are shown. Also the corrosion resistance of obtained alloy samples is determined.

Effect of temperature and pH of ammonium galvanic bath on the properties of Zn-Co alloy coatings

The results of investigations on Zn-Co coatings obtained electrochemically in acidic and neutral ammonium baths are presented. The chemical composition, morphology and surface roughness of received coatings were determined together with the current efficiency. It was found that the coatings morphology depends on the process parameters. In the case of neutral bath the increase of bath temperature resulted in decrease of cobalt contents in the coatings, whereas it was not practically observed for acidic baths. It was also observed that surface roughness of the Zn-Co coatings decreased with the increase of temperature for both types of baths. It was also found that the grain size of coatings obtained in neutral bath depends on pH of bath.