35 research outputs found
Study of calcium phosphate (DCPD) electrodeposition process on a Mg-3Al-1Zn magnesium alloy surface
Evaluation of calcium phosphating process realized on Mg-3Al-1Zn alloy surface after grinding was investigated by electrochemical tests supported by photodocumentation. The electrodeposition treatment was performed by electrochemical method in water solution of Ca(NO3)2.4H2O, (NH4)2HPO4 and H2O2. The formation of calcium phosphate was divided into several stages and described using light microscopy. The progress in corrosion protection of created calcium phosphate layer in 0.9% NaCl after particular electrodeposition steps was evaluated by electrochemical impedance spectroscopy. The results in the form of Nyquist plots were analyzed using equivalent circuits
Study of calcium phosphate (DCPD) electrodeposition process on a Mg-3Al-1Zn magnesium alloy surface
Evaluation of calcium phosphating process realized on Mg-3Al-1Zn alloy surface after grinding was investigated by electrochemical tests supported by photodocumentation. The electrodeposition treatment was performed by electrochemical method in water solution of Ca(NO3)2.4H2O, (NH4)2HPO4 and H2O2. The formation of calcium phosphate was divided into several stages and described using light microscopy. The progress in corrosion protection of created calcium phosphate layer in 0.9% NaCl after particular electrodeposition steps was evaluated by electrochemical impedance spectroscopy. The results in the form of Nyquist plots were analyzed using equivalent circuits
Corrosion resistance of AZ31 magnesium alloy influenced by conventional cutting fluid
This paper deals with the evaluation of cutting fluid impact on corrosion resistance of AZ31 magnesium alloy in aggressive environment containing chloride ions supported by photo documentation. Ground samples were immersed in the standard commercial cutting fluid for 5 minutes to simulate conditions during machining process at the temperature of 22 ± 2 °C and subsequently cleaned and immersed in 0.1M NaCl solution at the temperature of 22 ± 2°C in order to measure electrochemical corrosion characteristics. Cyclic potentiodynamic polarization (CPP) tests were chosen as a testing method. The measured CPP curves of immersed samples and ground samples were analysed by Tafel extrapolation method. The values of obtained electrochemical characteristics show that the chosen cutting fluid has negative effect on corrosion resistance of AZ31 magnesium alloy in sodium chloride solution.
Influence of mictrostructure features on the corrosion behaviourof AZ91 alloy in chloride media
The influence of the microstructure of as-cast AZ91 magnesium alloy, which applied to solution annealing treatment and ageing treatment respectively, was evaluated in terms of its corrosion behaviour in 0.1 M NaCl solution at room temperature. The corrosion process was monitored by electrochemical impedance spectroscopy (EIS) and the surface was characterized by scanning Kelvin probe force microscopy (SKPFM). The extent of corrosion damage was dependent on the microstructure. Surface potential maps indicated that, the surface potential of α-matrix is more positive than surface potential of β phase
The Corrosion Properties of S355J2 Steel Welded Joint in Chlorides Environment
Nowadays are steels the most used structural material for creation of constructions in different types of industry for lot of applications but suffer from unsatisfactory corrosion resistance in the presence of aggressive chlorides. Steel S355J2 represents common type steel for constructions. Very important property of S355J2 steel is weldability. S355J2 steel was welded by submerged arc welding (SAW) method. Corrosion resistance of welded joint was evaluated by electrochemical methods - linear polarization (LP) and electrochemical impedance spectroscopy (EIS). Results from electrochemical tests are general electrochemical characteristics - ECorr, iCorr, vCorr and RP. Environments for testing were solutions with different concentration of chlorides (0.01M, 0.1M and 1M NaCl solution). Difference of corrosion resistance between base material and weld metal is app. 14.5 %. This difference is preserved in all concentrations of tested environments. The highest corrosion resistance was reached by base material in 0.01M NaCl and the lowest corrosion resistance was reached by weld metal in 1M NaCl
INFLUENCE OF PHOSPHATIZED SURFACE LAYER ON CORROSION RESISTANCE OF Mg-Al-RE ALLOY
This contribution deals with evaluation of the corrosion resistance of extruded Mg-2Al-1RE (AE21) magnesium alloy in the state before and after treatment of ground surface by selected phosphatizing procedure. Specimens were exposed to 0.1M NaCl solution for several time periods starting from 5 minutes up-to 168 hours at room temperature of 22 ± 1 °C. Afterwards electrochemical impedance spectroscopy was carried out on the exposed specimens. Based on the results obtained from the electrochemical tests and visual observation of corrosion attack progress, positive or negative impact of selected phosphating process on the corrosion resistance of Mg-2Al-1RE magnesium alloy under given conditions was assessed
Study of calcium phosphate (DCPD) electrodeposition process on a Mg-3Al-1Zn magnesium alloy surface
Evaluation of calcium phosphating process realized on Mg-3Al-1Zn alloy surface after grinding was investigated by electrochemical tests supported by photodocumentation. The electrodeposition treatment was performed by electrochemical method in water solution of Ca(NO3)2.4H2O, (NH4)2HPO4 and H2O2. The formation of calcium phosphate was divided into several stages and described using light microscopy. The progress in corrosion protection of created calcium phosphate layer in 0.9% NaCl after particular electrodeposition steps was evaluated by electrochemical impedance spectroscopy. The results in the form of Nyquist plots were analyzed using equivalent circuits. </em
STUDY OF CALCIUM PHOSPHATE (DCPD) ELECTRODEPOSITION PROCESS ON THE Mg-3Al-1Zn MAGNESIUM ALLOY SURFACE
Evaluation of calcium phosphating process realized on the Mg-3Al-1Zn alloy surface after grinding was investigated by electrochemical tests supported by photodocumentation. The electrodeposition treatment was performed by electrochemical method in water solution of Ca(NO3)2.4H2O, (NH4)2HPO4 and H2O2. The formation of calcium phosphate was divided into several stages and described using light microscopy. The progress in corrosion protection of created calcium phosphate layer in 0.9% NaCl after particular electrodeposition steps was evaluated by electrochemical impedance spectroscopy. The results in the form of Nyquist plots were analyzed using equivalent circuits
Errata: Communications - Scientific Letters of the University of Zilina, Vol. 20, No. 3, 2018, "Electrochemical Characterization of Az31 Magnesium Alloy Treated by Ultrasonic Impact Peening (Uip)", pp. 24-29. The proper Acknowledgement should be as follow
Errata: Communications - Scientific Letters of the University of Zilina, Vol. 20, No. 3, 2018, "Electrochemical Characterization of Az31 Magnesium Alloy Treated by Ultrasonic Impact Peening (Uip)", pp. 24-29. The proper Acknowledgement should be as follows:The research was supported by project ITMS 26220220048 and by Slovak Research and Development Agency by the project No. APVV-14-0772