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Sovík J, Kajánek D, Pastorek F, Štrbák M, Florková Z, Jambor M, Hadzima B. The Effect of Mechanical Pretreatment on the Electrochemical Characteristics of PEO Coatings Prepared on Magnesium Alloy AZ80. Materials (Basel) 2023; 16:5650. [PMID: 37629940 PMCID: PMC10456923 DOI: 10.3390/ma16165650] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/14/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023]
Abstract
The main objective of this article is to provide new information on the effects of mechanical pretreatment of AZ80 magnesium alloy ground with SiC emery papers of different grain sizes on the plasma electrolytic oxidation (PEO) process and corrosion properties of AZ80 in 0.1 M NaCl solution. Then, the roughness of the coated samples was measured by confocal microscopy. The corrosion properties of the ground and coated surfaces were determined by potentiodynamic polarization (PDP) within 1 h of exposure, and electrochemical impedance spectroscopy (EIS) was performed during 168 h of exposure at laboratory temperature. Consequently, the obtained results of the PDP measurements were evaluated by the Tafel analysis and the EIS evaluation was performed by the equivalent circuit analysis through Nyquist diagrams. The morphology and structure of PEO coatings were observed by scanning electron microscopy (SEM) through the secondary imaging technology, and the presence of certain elements in PEO coatings was analyzed by EDS analysis.
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Affiliation(s)
- Ján Sovík
- Department of Materials Engineering, Faculty of Mechanical Engineering, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia;
| | - Daniel Kajánek
- Research Centre, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia; (D.K.); (F.P.); (Z.F.); (B.H.)
| | - Filip Pastorek
- Research Centre, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia; (D.K.); (F.P.); (Z.F.); (B.H.)
| | - Milan Štrbák
- Department of Materials Engineering, Faculty of Mechanical Engineering, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia;
| | - Zuzana Florková
- Research Centre, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia; (D.K.); (F.P.); (Z.F.); (B.H.)
| | - Michal Jambor
- Institute of Physics of Materials, Czech Academy of Sciences, Žižkova 513/22, 61600 Brno, Czech Republic;
| | - Branislav Hadzima
- Research Centre, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia; (D.K.); (F.P.); (Z.F.); (B.H.)
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Arsić D, Lazić V, Nikolić RR, Sczygiol N, Krstić B, Ivković D, Hadzima B, Pastorek F, Ulewicz R. Weldability Assessment of Various Steels by Hard-Facing. Materials 2022; 15:ma15093082. [PMID: 35591418 PMCID: PMC9102784 DOI: 10.3390/ma15093082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 04/21/2022] [Accepted: 04/21/2022] [Indexed: 02/05/2023]
Abstract
Two aspects of various steels’ weldability are considered in this article. The theoretical part presents general concepts related to steel’s weldability and the application of the most important methods for its determination. In the experimental section, results of the hard-facing application to several samples are presented, and consist of hardness measurements in the different zones of the welded samples, with the evaluation of those zones’ microstructures. The tested materials included two carbon steels and two alloyed steels, with hard-facing layers deposited by various filler metals. Experimental results were compared to results obtained by calculations; using both, authors were able to conclude which combination of filler metal, welding procedure and, if necessary, heat treatment, would achieve the optimal improvement of weldability in welding/hard-facing of each of the tested base metals.
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Affiliation(s)
- Dušan Arsić
- Faculty of Engineering, University of Kragujevac, Sestre Janjić 6, 34000 Kragujevac, Serbia; (D.A.); (V.L.); (B.K.); (D.I.)
| | - Vukić Lazić
- Faculty of Engineering, University of Kragujevac, Sestre Janjić 6, 34000 Kragujevac, Serbia; (D.A.); (V.L.); (B.K.); (D.I.)
| | - Ružica R. Nikolić
- Research Centre, University of Žilina, Univerzitna 8215/1, 010 26 Žilina, Slovakia; (B.H.); (F.P.)
- Correspondence:
| | - Norbert Sczygiol
- Faculty of Mechanical Engineering and Computer Science, Czestochowa University of Technology, 42201 Czestochowa, Poland;
| | - Božidar Krstić
- Faculty of Engineering, University of Kragujevac, Sestre Janjić 6, 34000 Kragujevac, Serbia; (D.A.); (V.L.); (B.K.); (D.I.)
| | - Djordje Ivković
- Faculty of Engineering, University of Kragujevac, Sestre Janjić 6, 34000 Kragujevac, Serbia; (D.A.); (V.L.); (B.K.); (D.I.)
| | - Branislav Hadzima
- Research Centre, University of Žilina, Univerzitna 8215/1, 010 26 Žilina, Slovakia; (B.H.); (F.P.)
| | - Filip Pastorek
- Research Centre, University of Žilina, Univerzitna 8215/1, 010 26 Žilina, Slovakia; (B.H.); (F.P.)
| | - Robert Ulewicz
- Department of Production Engineering and Safety, Czestochowa University of Technology, 42201 Czestochowa, Poland;
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Fintová S, Trško L, Chlup Z, Pastorek F, Kajánek D, Kunz L. Fatigue Crack Initiation Change of Cast AZ91 Magnesium Alloy from Low to Very High Cycle Fatigue Region. Materials (Basel) 2021; 14:ma14216245. [PMID: 34771771 PMCID: PMC8585000 DOI: 10.3390/ma14216245] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/12/2021] [Accepted: 10/15/2021] [Indexed: 12/02/2022]
Abstract
Fatigue tests were performed on the AZ91 cast alloy to identify the mechanisms of the fatigue crack initiation. In different fatigue regions, different mechanisms were observed. In the low and high cycle fatigue regions, slip markings formation accompanied with Mg17Al12 particles cracking were observed. Slip markings act as the fatigue crack initiation sites. The size and number of slip markings decreased with decreased stress amplitude applied. When slip markings formation was suppressed due to low stress amplitude, particle cracking became more important and the cracks continued to grow through the particle/solid solution interface. The change of the fatigue crack initiation mechanisms led the S-N curve to shift to the higher number of cycles to the fracture, demonstrated by its stepwise character. A lower fatigue limit of 60 MPa was determined at 20 kHz for 2 × 109 cycles compared to the 80 MPa determined at 60 Hz for 1 × 107 cycles.
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Affiliation(s)
- Stanislava Fintová
- Institute of Physics of Materials, Czech Academy of Sciences, Žižkova 22, 616 00 Brno, Czech Republic; (Z.C.); (L.K.)
- Correspondence: ; Tel.: +420-532-290-301
| | - Libor Trško
- Research Centre, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia; (L.T.); (F.P.); (D.K.)
| | - Zdeněk Chlup
- Institute of Physics of Materials, Czech Academy of Sciences, Žižkova 22, 616 00 Brno, Czech Republic; (Z.C.); (L.K.)
| | - Filip Pastorek
- Research Centre, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia; (L.T.); (F.P.); (D.K.)
| | - Daniel Kajánek
- Research Centre, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia; (L.T.); (F.P.); (D.K.)
| | - Ludvík Kunz
- Institute of Physics of Materials, Czech Academy of Sciences, Žižkova 22, 616 00 Brno, Czech Republic; (Z.C.); (L.K.)
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Neslušan M, Bahleda F, Moravčík M, Zgútová K, Pastorek F. Assessment of Tendon Prestressing after Long-Term Service via the Barkhausen Noise Technique. Materials (Basel) 2019; 12:ma12203450. [PMID: 31652504 PMCID: PMC6829388 DOI: 10.3390/ma12203450] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 10/19/2019] [Accepted: 10/20/2019] [Indexed: 11/23/2022]
Abstract
This paper deals with the assessment of a real prestressed tendon by the use of Barkhausen noise emission. The tendon was obtained from a real highway bridge after 33 years in service. Barkhausen noise is studied as a function of the stress state, and the Barkhausen noise signals received directly from the tendon on the real bridge are compared with the Barkhausen noise signals received from the tendon during loading in the laboratory. Assessment of the prestressing is based on the analysis of the effective value of the Barkhausen noise signal as well as the position in which the Barkhausen noise envelopes attain a maximum.
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Affiliation(s)
- Miroslav Neslušan
- Faculty of Mechanical Engineering, University of Žilina, Univerzitná 1, 01026 Žilina, Slovakia.
| | - František Bahleda
- Faculty of Civil Engineering, University of Žilina, Univerzitná 1, 01026 Žilina, Slovakia.
| | - Martin Moravčík
- Faculty of Civil Engineering, University of Žilina, Univerzitná 1, 01026 Žilina, Slovakia.
| | - Katarína Zgútová
- Faculty of Civil Engineering, University of Žilina, Univerzitná 1, 01026 Žilina, Slovakia.
| | - Filip Pastorek
- Research Centre, University of Žilina, Univerzitná 1, 01026 Žilina, Slovakia.
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Mhaede M, Pastorek F, Hadzima B. Influence of shot peening on corrosion properties of biocompatible magnesium alloy AZ31 coated by dicalcium phosphate dihydrate (DCPD). Materials Science and Engineering: C 2014; 39:330-5. [DOI: 10.1016/j.msec.2014.03.023] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/05/2014] [Accepted: 03/07/2014] [Indexed: 11/28/2022]
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Hadzima B, Mhaede M, Pastorek F. Electrochemical characteristics of calcium-phosphatized AZ31 magnesium alloy in 0.9 % NaCl solution. J Mater Sci Mater Med 2014; 25:1227-1237. [PMID: 24477876 DOI: 10.1007/s10856-014-5161-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 01/21/2014] [Indexed: 06/03/2023]
Abstract
Magnesium alloys suffer from their high reactivity in common environments. Protective layers are widely created on the surface of magnesium alloys to improve their corrosion resistance. This article evaluates the influence of a calcium-phosphate layer on the electrochemical characteristics of AZ31 magnesium alloy in 0.9 % NaCl solution. The calcium phosphate (CaP) layer was electrochemically deposited in a solution containing 0.1 M Ca(NO3)2, 0.06 M NH4H2PO4 and 10 ml l(-1) of H2O2. The formed surface layer was composed mainly of brushite [(dicalcium phosphate dihidrate (DCPD)] as proved by energy-dispersive X-ray analysis. The surface morphology was observed by scanning electron microscopy. Immersion test was performed in order to observe degradation of the calcium phosphatized surfaces. The influence of the phosphate layer on the electrochemical characteristics of AZ31, in 0.9 % NaCl solution, was evaluated by potentiodynamic measurements and electrochemical impedance spectroscopy. The obtained results were analysed by the Tafel-extrapolation method and equivalent circuits method. The results showed that the polarization resistance of the DCPD-coated surface is about 25 times higher than that of non-coated surface. The CaP electro-deposition process increased the activation energy of corrosion process.
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Affiliation(s)
- Branislav Hadzima
- Department of Materials Engineering, Faculty of Mechanical Engineering, University of Žilina, Univerzitná 1, 010 26, Zilina, Slovak Republic
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