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Kazamer N, Muntean R, Uțu ID, Mărginean G. Considerations on the Wear Behavior of Vacuum-Remelted ZrO 2-Reinforced Self-Fluxing Ni-Based Thermally Sprayed Alloys. Materials (Basel) 2023; 16:5183. [PMID: 37512457 PMCID: PMC10385681 DOI: 10.3390/ma16145183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 07/19/2023] [Accepted: 07/21/2023] [Indexed: 07/30/2023]
Abstract
Without proper post-processing (often using flame, furnace, laser remelting, and induction) or reinforcements' addition, Ni-based flame-sprayed coatings generally manifest moderate adhesion to the substrate, high porosity, unmelted particles, undesirable oxides, or weak wear resistance and mechanical properties. The current research aimed to investigate the addition of ZrO2 as reinforcement to the self-fluxing alloy coatings. Mechanically mixed NiCrBSi-ZrO2 powders were thermally sprayed onto an industrially relevant high-grade steel. After thermal spraying, the samples were differently post-processed with a flame gun and with a vacuum furnace, respectively. Scanning electron microscopy showed a porosity reduction for the vacuum-heat-treated samples compared to that of the flame-post-processed ones. X-ray diffraction measurements showed differences in the main peaks of the patterns for the thermal processed samples compared to the as-sprayed ones, these having a direct influence on the mechanical behavior of the coatings. Although a slight microhardness decrease was observed in the case of vacuum-remelted samples, the overall low porosity and the phase differences helped the coating to perform better during wear-resistance testing, realized using a ball-on-disk arrangement, compared to the as-sprayed reference samples.
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Affiliation(s)
- Norbert Kazamer
- Westphalian Energy Institute, Westphalian University of Applied Sciences, Neidenburgerstr. 43, 45897 Gelsenkirchen, Germany
| | - Roxana Muntean
- Materials and Manufacturing Engineering Department, Faculty of Mechanical Engineering, Politehnica University of Timișoara, Bvd. Mihai Viteazu nr. 1, 300222 Timișoara, Romania
| | - Ion-Dragoș Uțu
- Materials and Manufacturing Engineering Department, Faculty of Mechanical Engineering, Politehnica University of Timișoara, Bvd. Mihai Viteazu nr. 1, 300222 Timișoara, Romania
| | - Gabriela Mărginean
- Institute of Mechanical Engineering, Westphalian University of Applied Sciences, Neidenburgerstr. 43, 45897 Gelsenkirchen, Germany
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Cieluch M, Podleschny PY, Kazamer N, Wirkert FJ, Rost UW, Brodmann M. Development of a Bifunctional Ti-Based Gas Diffusion Electrode for ORR and OER by One- and Two-Step Pt-Ir Electrodeposition. Nanomaterials (Basel) 2022; 12:nano12071233. [PMID: 35407351 PMCID: PMC9003547 DOI: 10.3390/nano12071233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 03/09/2022] [Revised: 03/25/2022] [Accepted: 04/01/2022] [Indexed: 11/23/2022]
Abstract
The present paper presents one- and two-step approaches for electrochemical Pt and Ir deposition on a porous Ti-substrate to obtain a bifunctional oxygen electrode. Surface pre-treatment of the fiber-based Ti-substrate with oxalic acid provides an alternative to plasma treatment for partially stripping TiO2 from the electrode surface and roughening the topography. Electrochemical catalyst deposition performed directly onto the pretreated Ti-substrates bypasses unnecessary preparation and processing of catalyst support structures. A single Pt constant potential deposition (CPD), directly followed by pulsed electrodeposition (PED), created nanosized noble agglomerates. Subsequently, Ir was deposited via PED onto the Pt sub-structure to obtain a successively deposited PtIr catalyst layer. For the co-deposition of PtIr, a binary PtIr-alloy electrolyte was used applying PED. Micrographically, areal micro- and nano-scaled Pt sub-structure were observed, supplemented by homogenously distributed, nanosized Ir agglomerates for the successive PtIr deposition. In contrast, the PtIr co-deposition led to spherical, nanosized PtIr agglomerates. The electrochemical ORR and OER activity showed increased hydrogen desorption peaks for the Pt-deposited substrate, as well as broadening and flattening of the hydrogen desorption peaks for PtIr deposited substrates. The anodic kinetic parameters for the prepared electrodes were found to be higher than those of a polished Ir-disc.
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Affiliation(s)
- Maximilian Cieluch
- Westphalian Energy Institute, Westphalian University of Applied Sciences Gelsenkirchen Bocholt Recklinghausen, Neidenburger Str. 43, 45897 Gelsenkirchen, Germany; (P.Y.P.); (F.J.W.); (U.W.R.); (M.B.)
- Correspondence: (M.C.); (N.K.); Tel.: +49-209-9596-807 (M.C.); +49-209-9596-5089 (N.K.)
| | - Pit Yannick Podleschny
- Westphalian Energy Institute, Westphalian University of Applied Sciences Gelsenkirchen Bocholt Recklinghausen, Neidenburger Str. 43, 45897 Gelsenkirchen, Germany; (P.Y.P.); (F.J.W.); (U.W.R.); (M.B.)
| | - Norbert Kazamer
- Westphalian Energy Institute, Westphalian University of Applied Sciences Gelsenkirchen Bocholt Recklinghausen, Neidenburger Str. 43, 45897 Gelsenkirchen, Germany; (P.Y.P.); (F.J.W.); (U.W.R.); (M.B.)
- Correspondence: (M.C.); (N.K.); Tel.: +49-209-9596-807 (M.C.); +49-209-9596-5089 (N.K.)
| | - Florian Josef Wirkert
- Westphalian Energy Institute, Westphalian University of Applied Sciences Gelsenkirchen Bocholt Recklinghausen, Neidenburger Str. 43, 45897 Gelsenkirchen, Germany; (P.Y.P.); (F.J.W.); (U.W.R.); (M.B.)
| | - Ulrich Wilhelm Rost
- Westphalian Energy Institute, Westphalian University of Applied Sciences Gelsenkirchen Bocholt Recklinghausen, Neidenburger Str. 43, 45897 Gelsenkirchen, Germany; (P.Y.P.); (F.J.W.); (U.W.R.); (M.B.)
- ProPuls GmbH, Neidenburger Str. 10, 45897 Gelsenkirchen, Germany
| | - Michael Brodmann
- Westphalian Energy Institute, Westphalian University of Applied Sciences Gelsenkirchen Bocholt Recklinghausen, Neidenburger Str. 43, 45897 Gelsenkirchen, Germany; (P.Y.P.); (F.J.W.); (U.W.R.); (M.B.)
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Muntean R, Pascal DT, Kazamer N, Mărginean G, Șerban VA. Sliding Wear Behavior of High-Temperature Vacuum-Brazed WC-Co-NiP Functional Composite Coatings. Materials (Basel) 2021; 15:88. [PMID: 35009231 PMCID: PMC8746236 DOI: 10.3390/ma15010088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/20/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
The present study aimed to investigate the tribological behavior of high-temperature vacuum-brazed WC-Co-NiP functional coatings deposited on 16MnCr5 case hardening steel. Dry sliding wear resistance was evaluated using a non-conformal ball-on-disk arrangement, at room temperature against 100Cr6 and WC-Co static partners, respectively. Morphological, microstructural, and chemical composition analyses showed a complex, phased structure composed of tungsten carbide, nickel, and hard cobalt-based η-structure. In the testing conditions, the coefficient of friction against 100Cr6 and WC-Co counterparts entered a steady-state value after approximately 1000 m and 400 m, respectively. The wear track analysis revealed phenomena of particles trapped between the sliding bodies, as well as gradual removal of asperities. The calculations of the wear rates proved that the values were strongly influenced by properties of the sliding system, such as crystal structure, stress discontinuities, hardness, and material homogeneity.
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Affiliation(s)
- Roxana Muntean
- Department of Materials and Manufacturing Engineering, University Politehnica of Timișoara, Piața Victoriei 2, 300006 Timisoara, Romania; (R.M.); (V.-A.Ș.)
| | - Dragoș-Toader Pascal
- Westphalian Energy Institute, Westphalian University of Applied Sciences Gelsenkirchen Bocholt Recklinghausen, Neidenburgerstr. 43, 45897 Gelsenkirchen, Germany;
| | - Norbert Kazamer
- Westphalian Energy Institute, Westphalian University of Applied Sciences Gelsenkirchen Bocholt Recklinghausen, Neidenburgerstr. 43, 45897 Gelsenkirchen, Germany;
| | - Gabriela Mărginean
- Department of Materials Science and Testing, Westphalian University of Applied Sciences Gelsenkirchen Bocholt Recklinghausen, Neidenburgerstr. 43, 45897 Gelsenkirchen, Germany
| | - Viorel-Aurel Șerban
- Department of Materials and Manufacturing Engineering, University Politehnica of Timișoara, Piața Victoriei 2, 300006 Timisoara, Romania; (R.M.); (V.-A.Ș.)
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Kiryc M, Kazamer N, Kurumlu D, Marginean G. Comparative Study on the Thermal Performance of Cr-Cr xO y and YSZ-CoNiCrAlY Coatings Exposed at 900 °C. Materials (Basel) 2021; 14:ma14206040. [PMID: 34683628 PMCID: PMC8541463 DOI: 10.3390/ma14206040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 09/14/2021] [Revised: 10/04/2021] [Accepted: 10/08/2021] [Indexed: 01/09/2023]
Abstract
Yttria stabilized zirconia (YSZ) thermal barrier coatings (TBCs) deposited on CoNiCrAlY oxidation protective bond coats are commonly required in temperature regimes up to 1200 °C (e.g., hot gas turbine regions) due to their superior thermal behavior and mechanical properties. For temperatures up to around 900 °C, oxidation protection can be alternatively provided by metallic-ceramic Cr-CrxOy coatings. For the present research, Cr-CrxOy atmospheric plasma sprayed (APS) and YSZ-CoNiCrAlY APS-high velocity oxy-fuel TBC coatings were deposited on a NiCr20Co18Ti substrate. The samples were isothermally heat treated at 900 °C for 10 h in an environmental atmosphere and subsequently isothermally oxidized at the same temperature for 1200 h. Investigations of the physical, chemical, and mechanical properties were performed on the as-sprayed, heat-treated, and oxidized samples. The oxidation behavior, microhardness, cohesion, and adhesion of the samples were correlated with the microstructural investigations and compared to the conventional TBC system. It could be shown that heat treating decreased the Cr-CrxOy coatings crack susceptibility and led to the formation of a protective thermally grown Cr oxide layer. The experimental work on the YSZ-CoNiCrAlY system revealed that the phase composition of the bond coat has a direct influence on the oxidation protection of the coating system.
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Affiliation(s)
- Markus Kiryc
- Department of Materials Science and Testing, Westphalian University of Applied Sciences Gelsenkirchen Bocholt Recklinghausen, Neidenburger Str. 43, 45897 Gelsenkirchen, Germany; (M.K.); (D.K.); (G.M.)
| | - Norbert Kazamer
- Westphalian Energy Institute, Westphalian University of Applied Sciences Gelsenkirchen Bocholt Recklinghausen, Neidenburger Str. 43, 45897 Gelsenkirchen, Germany
- Correspondence: ; Tel.: +49-209-959-65089
| | - Deniz Kurumlu
- Department of Materials Science and Testing, Westphalian University of Applied Sciences Gelsenkirchen Bocholt Recklinghausen, Neidenburger Str. 43, 45897 Gelsenkirchen, Germany; (M.K.); (D.K.); (G.M.)
| | - Gabriela Marginean
- Department of Materials Science and Testing, Westphalian University of Applied Sciences Gelsenkirchen Bocholt Recklinghausen, Neidenburger Str. 43, 45897 Gelsenkirchen, Germany; (M.K.); (D.K.); (G.M.)
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Militaru BA, Pode R, Lupa L, Schmidt W, Tekle-Röttering A, Kazamer N. Using Sewage Sludge Ash as an Efficient Adsorbent for Pb (II) and Cu (II) in Single and Binary Systems. Molecules 2020; 25:molecules25112559. [PMID: 32486401 PMCID: PMC7321074 DOI: 10.3390/molecules25112559] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 05/28/2020] [Accepted: 05/29/2020] [Indexed: 11/16/2022] Open
Abstract
Incineration of sewage sludge produces every year huge amounts of sewage sludge ash. Due to its porosity and composition, sewage sludge ash can be used as an adsorbent for heavy metal ions removal. The present paper discusses the efficiency and feasibility of its use as an adsorbent for Pb (II) and Cu (II) removal in single and binary systems. Sewage sludge ash dosage, pH influence, equilibrium and kinetic studies were examined. The results show that sewage sludge ash is an effective and environmentally friendly adsorbent. The maximum adsorption capacity was 25.0 mg/g for Pb (II) and 7.5 mg/g for Cu (II). The presence of the competitive metal led to lower adsorption rate. The study concludes that sewage sludge ash is a promising adsorbent for Pb (II) and Cu (II) removal from wastewater presenting both economic and environmental benefits.
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Affiliation(s)
- Bogdan Adrian Militaru
- Faculty of Industrial Chemistry and Environmental, Politehnica University of Timisoara, 300006 Timisoara, Romania; (R.P.); (L.L.)
- Correspondence: ; Tel.: +40-729811595
| | - Rodica Pode
- Faculty of Industrial Chemistry and Environmental, Politehnica University of Timisoara, 300006 Timisoara, Romania; (R.P.); (L.L.)
| | - Lavinia Lupa
- Faculty of Industrial Chemistry and Environmental, Politehnica University of Timisoara, 300006 Timisoara, Romania; (R.P.); (L.L.)
| | - Winfried Schmidt
- Westfälische Hochschule, University of Applied Sciences, 45897 Gelsenkirchen, Germany; (W.S.); (A.T.-R.); (N.K.)
| | - Agnes Tekle-Röttering
- Westfälische Hochschule, University of Applied Sciences, 45897 Gelsenkirchen, Germany; (W.S.); (A.T.-R.); (N.K.)
| | - Norbert Kazamer
- Westfälische Hochschule, University of Applied Sciences, 45897 Gelsenkirchen, Germany; (W.S.); (A.T.-R.); (N.K.)
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Kazamer N, Vălean PC, Pascal DT, Muntean R, Mărginean GM, Șerban VA. Microstructure and Phase Composition of NiCrBSi-TiB2 Vacuum Furnace Fused Flame-Sprayed Coatings. ACTA ACUST UNITED AC 2018. [DOI: 10.1088/1757-899x/416/1/012001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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