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Kozadaeva M, Surmeneva M, Khrapov D, Rybakov V, Surmenev R, Koptyug A, Vladescu Dragomir A, Cotrut CM, Tyurin A, Grubova I. Assessment of Microstructural, Mechanical and Electrochemical Properties of Ti-42Nb Alloy Manufactured by Electron Beam Melting. Materials (Basel) 2023; 16:4821. [PMID: 37445133 DOI: 10.3390/ma16134821] [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] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/20/2023] [Accepted: 06/30/2023] [Indexed: 07/15/2023]
Abstract
The β-type Ti-42Nb alloy has been successfully manufactured from pre-alloyed powder using the E-PBF method for the first time. This study presents thorough microstructural investigations employing diverse methodologies such as EDS, XRD, TEM, and EBSD, while mechanical properties are assessed using UPT, nanoindentation, and compression tests. Microstructural analysis reveals that Ti-42Nb alloy primarily consisted of the β phase with the presence of a small amount of nano-sized α″-martensite formed upon fast cooling. The bimodal-grained microstructure of Ti-42Nb alloy comprising epitaxially grown fine equiaxed and elongated equiaxed β-grains with an average grain size of 40 ± 28 µm exhibited a weak texture. The study shows that the obtained microstructure leads to improved mechanical properties. Young's modulus of 78.69 GPa is significantly lower than that of cp-Ti and Ti-6Al-4V alloys. The yield strength (379 MPa) and hardness (3.2 ± 0.5 GPa) also meet the criteria and closely approximate the values typical of cortical bone. UPT offers a reliable opportunity to study the nature of the ductility of the Ti-42Nb alloy by calculating its elastic constants. XPS surface analysis and electrochemical experiments demonstrate that the better corrosion resistance of the alloy in SBF is maintained by the dominant presence of TiO2 and Nb2O5. The results provide valuable insights into the development of novel low-modulus Ti-Nb alloys, which are interesting materials for additive-manufactured implants with the desired properties required for their biomedical applications.
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Affiliation(s)
- Maria Kozadaeva
- Physical Materials Science and Composite Materials Centre, Research School of Chemistry & Applied Biomedical Sciences, National Research Tomsk Polytechnic University, 30 Lenina Avenue, 634050 Tomsk, Russia
| | - Maria Surmeneva
- Physical Materials Science and Composite Materials Centre, Research School of Chemistry & Applied Biomedical Sciences, National Research Tomsk Polytechnic University, 30 Lenina Avenue, 634050 Tomsk, Russia
| | - Dmitriy Khrapov
- Physical Materials Science and Composite Materials Centre, Research School of Chemistry & Applied Biomedical Sciences, National Research Tomsk Polytechnic University, 30 Lenina Avenue, 634050 Tomsk, Russia
| | - Vladimir Rybakov
- International Research and Development Center "Piezo- and Magnetoelectric Materials", Research School of Chemistry and Applied Biomedical Sciences, National Research Tomsk Polytechnic University, 30 Lenina Avenue, 634050 Tomsk, Russia
| | - Roman Surmenev
- Physical Materials Science and Composite Materials Centre, Research School of Chemistry & Applied Biomedical Sciences, National Research Tomsk Polytechnic University, 30 Lenina Avenue, 634050 Tomsk, Russia
| | - Andrey Koptyug
- Sports Tech Research Centre, Mid Sweden University, Akademigatan 1, SE 83125 Östersund, Sweden
| | - Alina Vladescu Dragomir
- Physical Materials Science and Composite Materials Centre, Research School of Chemistry & Applied Biomedical Sciences, National Research Tomsk Polytechnic University, 30 Lenina Avenue, 634050 Tomsk, Russia
- National Institute of Research and Development for Optoelectronics INOE 2000, 409 Atomistilor St., 77125 Magurele, Romania
| | - Cosmin Mihai Cotrut
- Faculty of Materials and Science Engineering, University Politehnica of Bucharest, 313, Spl. Independentei, 060042 Bucharest, Romania
| | - Alexander Tyurin
- Institute "Nanotechnology and Nanomaterials", G.R. Derzhavin Tambov State University, 33 Internationalnaya St., 392000 Tambov, Russia
| | - Irina Grubova
- Physical Materials Science and Composite Materials Centre, Research School of Chemistry & Applied Biomedical Sciences, National Research Tomsk Polytechnic University, 30 Lenina Avenue, 634050 Tomsk, Russia
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Bita T, Antoniac A, Ciuca I, Miculescu M, Cotrut CM, Paltanea G, Dura H, Corneschi I, Antoniac I, Carstoc ID, Bodog AD. Effect of Fluoride Coatings on the Corrosion Behavior of Mg-Zn-Ca-Mn Alloys for Medical Application. Materials (Basel) 2023; 16:4508. [PMID: 37444822 DOI: 10.3390/ma16134508] [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] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/14/2023] [Accepted: 06/15/2023] [Indexed: 07/15/2023]
Abstract
The most critical shortcoming of magnesium alloys from the point of view of medical devices is the high corrosion rate, which is not well-correlated with clinical needs. It is well- known that rapid degradation occurs when an implant made of Mg-based alloys is placed inside the human body. Consequently, the implant loses its mechanical properties and failure can occur even if it is not completely degraded. The corrosion products that appear after Mg-based alloy degradation, such as H2 and OH- can have an essential role in decreasing biocompatibility due to the H2 accumulation process in the tissues near the implant. In order to control the degradation process of the Mg-based alloys, different coatings could be applied. The aim of the current paper is to evaluate the effect of fluoride coatings on the corrosion behavior of magnesium alloys from the system Mg-Zn-Ca-Mn potentially used for orthopedic trauma implants. The main functional properties required for the magnesium alloys to be used as implant materials, such as surface properties and corrosion behavior, were studied before and after surface modifications by fluoride conversion, with and without preliminary sandblasting, of two magnesium alloys from the system Mg-Zn-Ca-Mn. The experimental results showed that chemical conversion treatment with hydrofluoric acid is useful as a method of increasing corrosion resistance for the experimental magnesium alloys from the Mg-Zn-Ca-Mn system. Also, high surface free energy values obtained for the alloys treated with hydrofluoric acid correlated with wettability lead to the conclusion that there is an increased chance for biological factor adsorption and cell proliferation. Chemical conversion treatment with hydrofluoric acid is useful as a method of increasing corrosion resistance for the experimental Mg-Zn-Ca-Mn alloys.
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Affiliation(s)
- Tiberiu Bita
- Faculty of Material Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, District 6, 060042 Bucharest, Romania
| | - Aurora Antoniac
- Faculty of Material Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, District 6, 060042 Bucharest, Romania
| | - Ion Ciuca
- Faculty of Material Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, District 6, 060042 Bucharest, Romania
| | - Marian Miculescu
- Faculty of Material Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, District 6, 060042 Bucharest, Romania
| | - Cosmin Mihai Cotrut
- Faculty of Material Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, District 6, 060042 Bucharest, Romania
| | - Gheorghe Paltanea
- Faculty of Electrical Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, District 6, 060042 Bucharest, Romania
| | - Horatiu Dura
- Faculty of Medicine, Lucian Blaga University of Sibiu, 2A Lucian Blaga Street, 550169 Sibiu, Romania
| | - Iuliana Corneschi
- Romfire Protect Solution S.R.L., 39 Drumul Taberei, District 6, 061359 Bucharest, Romania
| | - Iulian Antoniac
- Faculty of Material Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, District 6, 060042 Bucharest, Romania
- Academy of Romania Scientist, 54 Splaiul Independentei, 050094 Bucharest, Romania
| | - Ioana Dana Carstoc
- Faculty of Medicine, Lucian Blaga University of Sibiu, 2A Lucian Blaga Street, 550169 Sibiu, Romania
| | - Alin Danut Bodog
- Faculty of Medicine and Pharmacy, University of Oradea, 10 P-ta 1 December Street, 410073 Oradea, Romania
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Cojocaru MO, Branzei M, Ciuca S, Gherghescu IA, Ion M, Druga LN, Cotrut CM. Sulfonitrocarburizing of High-Speed Steel Cutting Tools: Kinetics and Performances. Materials (Basel) 2021; 14:ma14247779. [PMID: 34947373 PMCID: PMC8707416 DOI: 10.3390/ma14247779] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/04/2021] [Accepted: 12/08/2021] [Indexed: 11/16/2022]
Abstract
The scholarly literature records information related to the performance increase of the cutting tools covered by the superficial layers formed “in situ” when applying thermochemical processing. In this context, information is frequently reported on the carbamide role in processes aiming carbon and nitrogen surface saturation. Sulfur, together with these elements adsorbed and diffused in the cutting tools superficial layers, undoubtedly ensures an increase of their operating sustainability. The present paper discusses the process of sulfonitrocarburizing in pulverulent solid media of high-speed tools steel (AISI T1, HS18-0-1) and its consequences. The peculiarity of the considered process is that the source of nitrogen and carbon is mainly carbamide (CON2H4), which is found in solid powdery mixtures together with components that do not lead to cyan complex formation (non-toxic media), and the sulfur source is native sulfur. The kinetics of the sulfonitrocarburizing process, depending on the carbamide proportion in the powdered solid mixture and the processing temperature, was studied. The consequences of the achieved sulfonitrocarburized layers on the cutting tools’ performance are expressed by the maximum permissible cutting speed and the maximum cut length. An interesting aspect is highlighted, namely the possibility of using chemically active mixtures. Their components, by initiation of the metallothermic reduction reaction, become able to provide both elements of interest and the amount of heat needed for the ultrafast saturation of the targeted metal surfaces.
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Affiliation(s)
- Mihai Ovidiu Cojocaru
- Department of Metallic Materials Science, Physical Metallurgy, Faculty of Materials Science and Engineering, University POLITEHNICA of Bucharest, 060042 Bucharest, Romania; (M.O.C.); (S.C.); (I.A.G.); (M.I.); (C.M.C.)
- Section IX-Materials Science and Engineering, Technical Sciences Academy of Romania, 030167 Bucharest, Romania;
| | - Mihai Branzei
- Department of Metallic Materials Science, Physical Metallurgy, Faculty of Materials Science and Engineering, University POLITEHNICA of Bucharest, 060042 Bucharest, Romania; (M.O.C.); (S.C.); (I.A.G.); (M.I.); (C.M.C.)
- Correspondence: ; Tel.: +40-21-402-9874
| | - Sorin Ciuca
- Department of Metallic Materials Science, Physical Metallurgy, Faculty of Materials Science and Engineering, University POLITEHNICA of Bucharest, 060042 Bucharest, Romania; (M.O.C.); (S.C.); (I.A.G.); (M.I.); (C.M.C.)
| | - Ioana Arina Gherghescu
- Department of Metallic Materials Science, Physical Metallurgy, Faculty of Materials Science and Engineering, University POLITEHNICA of Bucharest, 060042 Bucharest, Romania; (M.O.C.); (S.C.); (I.A.G.); (M.I.); (C.M.C.)
| | - Mariana Ion
- Department of Metallic Materials Science, Physical Metallurgy, Faculty of Materials Science and Engineering, University POLITEHNICA of Bucharest, 060042 Bucharest, Romania; (M.O.C.); (S.C.); (I.A.G.); (M.I.); (C.M.C.)
| | - Leontin Nicolae Druga
- Section IX-Materials Science and Engineering, Technical Sciences Academy of Romania, 030167 Bucharest, Romania;
| | - Cosmin Mihai Cotrut
- Department of Metallic Materials Science, Physical Metallurgy, Faculty of Materials Science and Engineering, University POLITEHNICA of Bucharest, 060042 Bucharest, Romania; (M.O.C.); (S.C.); (I.A.G.); (M.I.); (C.M.C.)
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Popescu D, Baciu F, Amza CG, Cotrut CM, Marinescu R. The Effect of Disinfectants Absorption and Medical Decontamination on the Mechanical Performance of 3D-Printed ABS Parts. Polymers (Basel) 2021; 13:4249. [PMID: 34883752 PMCID: PMC8659898 DOI: 10.3390/polym13234249] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 11/23/2021] [Accepted: 12/02/2021] [Indexed: 12/13/2022] Open
Abstract
Producing parts by 3D printing based on the material extrusion process determines the formation of air gaps within layers even at full infill density, while external pores can appear between adjacent layers making prints permeable. For the 3D-printed medical devices, this open porosity leads to the infiltration of disinfectant solutions and body fluids, which might pose safety issues. In this context, this research purpose is threefold. It investigates which 3D printing parameter settings are able to block or reduce permeation, and it experimentally analyzes if the disinfectants and the medical decontamination procedure degrade the mechanical properties of 3D-printed parts. Then, it studies acetone surface treatment as a solution to avoid disinfectants infiltration. The absorption tests results indicate the necessity of applying post-processing operations for the reusable 3D-printed medical devices as no manufacturing settings can ensure enough protection against fluid intake. However, some parameter settings were proven to enhance the sealing, in this sense the layer thickness being the most important factor. The experimental outcomes also show a decrease in the mechanical performance of 3D-printed ABS (acrylonitrile butadiene styrene) instruments treated by acetone cold vapors and then medical decontaminated (disinfected, cleaned, and sterilized by hydrogen peroxide gas plasma sterilization) in comparison to the control prints. These results should be acknowledged when designing and 3D printing medical instruments.
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Affiliation(s)
- Diana Popescu
- Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, Romania; (D.P.); (C.G.A.)
| | - Florin Baciu
- Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, Romania; (D.P.); (C.G.A.)
| | - Catalin Gheorghe Amza
- Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, Romania; (D.P.); (C.G.A.)
| | - Cosmin Mihai Cotrut
- Faculty of Materials Science and Engineering, University Politehnica of Bucharest, 060042 Bucharest, Romania;
| | - Rodica Marinescu
- Department of Orthopedics, University of Medicine and Pharmacology Carol Davila, 020021 Bucharest, Romania;
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Fischer P, Barbu HM, Fischer CAI, Pantea M, Baciu F, Vranceanu DM, Cotrut CM, Spinu TC. Bending Fracture of Different Zirconia-Based Bioceramics for Dental Applications: A Comparative Study. Materials (Basel) 2021; 14:ma14226887. [PMID: 34832293 PMCID: PMC8621405 DOI: 10.3390/ma14226887] [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: 10/25/2021] [Revised: 11/08/2021] [Accepted: 11/10/2021] [Indexed: 01/09/2023]
Abstract
The fabrication of fixed dental prostheses using aesthetic materials has become routine in today’s dentistry. In the present study, three-unit full zirconia fixed prosthetic restorations obtained by computer-aided design/computer-aided manufacturing (CAD/CAM) technology were tested by bending trials. The prostheses were intended to replace the first mandibular left molar and were manufactured from four different types of zirconia bioceramics (KatanaTM Zirconia HTML and KatanaTM Zirconia STML/Kuraray Noritake Dental Inc.; NOVAZir® Fusion float® ml/NOVADENT/Dentaltechnik; and 3D PRO Zirconia/Bloomden Bioceramics). In total, sixteen samples were manufactured—four samples per zirconia material. Additionally, the morphology, grain size area distribution, and elemental composition were analyzed in parallelepiped samples made from the selected types of zirconia in three different areas, noted as the upper, middle, and lower areas. The scanning electron microscope (SEM) analysis highlighted that the grain size area varies with respect to the researched area and the type of material. Defects such as microcracks and pores were also noted to a smaller extent. In terms of grain size area, it was observed that most of the particles in all samples were under 0.5 μm2, while the chemical composition of the investigated materials did not vary significantly. The results obtained after performing the bending tests showed that a zirconia material with fewer structural defects and an increased percentage of grain size area under 0.5 µm2, ranging from ~44% in the upper area to ~74% in the lower area, exhibited enhanced mechanical behavior. Overall, the resulting values of all investigated parameters confirm that the tested materials are suitable for clinical use.
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Affiliation(s)
- Peter Fischer
- Oral Implantology Department, Titu Maiorescu University, 67A Gh. Petrascu Street, 040441 Bucharest, Romania; (P.F.); (H.M.B.)
| | - Horia Mihail Barbu
- Oral Implantology Department, Titu Maiorescu University, 67A Gh. Petrascu Street, 040441 Bucharest, Romania; (P.F.); (H.M.B.)
| | - Caroline Adela Ingrid Fischer
- Doctoral School, Faculty of Dental Medicine, Titu Maiorescu University, 67A Gh. Petrascu Street, 040441 Bucharest, Romania;
| | - Mihaela Pantea
- Department of Fixed Prosthodontics and Occlusology, Faculty of Dental Medicine, Carol Davila University of Medicine and Pharmacy, 17-23 Plevnei Street, 010221 Bucharest, Romania; (M.P.); (T.C.S.)
| | - Florin Baciu
- Department of Strength of Materials, Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania;
| | - Diana Maria Vranceanu
- Department of Metallic Materials Science, Physical Metallurgy, Faculty of Materials Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania
- Correspondence: (D.M.V.); (C.M.C.); Tel.: +40-(0)21-316-9563 (D.M.V. & C.M.C.)
| | - Cosmin Mihai Cotrut
- Department of Metallic Materials Science, Physical Metallurgy, Faculty of Materials Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania
- Correspondence: (D.M.V.); (C.M.C.); Tel.: +40-(0)21-316-9563 (D.M.V. & C.M.C.)
| | - Tudor Claudiu Spinu
- Department of Fixed Prosthodontics and Occlusology, Faculty of Dental Medicine, Carol Davila University of Medicine and Pharmacy, 17-23 Plevnei Street, 010221 Bucharest, Romania; (M.P.); (T.C.S.)
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Bechir F, Bataga SM, Ungureanu E, Vranceanu DM, Pacurar M, Bechir ES, Cotrut CM. Experimental Study Regarding the Behavior at Different pH of Two Types of Co-Cr Alloys Used for Prosthetic Restorations. Materials (Basel) 2021; 14:ma14164635. [PMID: 34443157 PMCID: PMC8402223 DOI: 10.3390/ma14164635] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 07/26/2021] [Revised: 08/11/2021] [Accepted: 08/13/2021] [Indexed: 12/12/2022]
Abstract
Cobalt-chromium (Co-Cr) alloys are widely utilized in dentistry. The salivary pH is a significant factor, which affects the characteristics and the behavior of dental alloys through corrosion. This study aimed to evaluate the corrosion behavior in artificial saliva with different pH values (3, 5.7, and 7.6) of two commercial Co-Cr dental alloys manufactured by casting and by milling. Corrosion resistance was determined by the polarization resistance technique, and the tests were carried out at 37 ± 1 °C, in Carter Brugirard artificial saliva. After the electrochemical parameters, it can be stated that the cast Co-Cr alloy has the lowest corrosion current density, the highest polarization resistance, and the lowest speed of corrosion in artificial saliva with pH = 7.6. In the case of milled Co-Cr alloy, the same behavior was observed, but in artificial saliva with pH = 5.7, it recorded the most electropositive values of open circuit potential and corrosion potential. Although both cast and milled Co-Cr alloys presented a poorer corrosion resistance in artificial saliva with a more acidic pH value, the milled Co-Cr alloy had better corrosion behavior, making this alloy a better option for the prosthetic treatment of patients suffering from GERD.
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Affiliation(s)
- Farah Bechir
- Faculty of Dental Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures, 38 Gh. Marinescu Str., 540142 Targu Mures, Romania; (F.B.); (M.P.)
| | - Simona Maria Bataga
- Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures, 38 Gh. Marinescu Str., 540142 Targu Mures, Romania;
| | - Elena Ungureanu
- Faculty of Materials Science and Engineering, Politehnica University of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania; (E.U.); (D.M.V.); (C.M.C.)
| | - Diana Maria Vranceanu
- Faculty of Materials Science and Engineering, Politehnica University of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania; (E.U.); (D.M.V.); (C.M.C.)
| | - Mariana Pacurar
- Faculty of Dental Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures, 38 Gh. Marinescu Str., 540142 Targu Mures, Romania; (F.B.); (M.P.)
| | - Edwin Sever Bechir
- Faculty of Dental Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures, 38 Gh. Marinescu Str., 540142 Targu Mures, Romania; (F.B.); (M.P.)
- Correspondence: ; Tel.: +40-72-339-6969
| | - Cosmin Mihai Cotrut
- Faculty of Materials Science and Engineering, Politehnica University of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania; (E.U.); (D.M.V.); (C.M.C.)
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Mahu G, Munteanu C, Istrate B, Blanari I, Paleu C, Cotrut CM. Evaluation of the Corrosion Resistance of Some Coating Obtained by Thermal Spray in Plasma Jet, on the Surface of Some Crankshafts Made of C45 Steel. Rev Chim 2020. [DOI: 10.37358/rc.20.10.8366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
For modern engines the oil change interval can reach up to 30,000 km. If the oils lose their properties and are contaminated, they can adversely affect the corrosion resistance, the surface of the main bearing journals and the main journals of the crankshafts. In this study, the results obtained from the corrosion process were analyzed, in a solution of 3.5% NaCl of the layers obtained after spraying the surface of a C45 steel, used in the construction of crankshafts, with three powders: Cr3C2-(Ni20Cr), Al2O3-13TiO2, Cr2O3-SiO2-TiO2. The corrosion process was determined by the potentiodynamic polarization technique. The variations in time of the open-circuit potential and the Tafel curves were analyzed, for the samples with deposited layers and the basic material. Morphology and characterization of the structure of the layers after corrosion were performed by means of SEM microscopy and EDAX analysis. The results confirm that the powders sprayed by the atmospheric plasma spray method protect the surface of C45 steel from corrosion.
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Sandu IG, Vasilache V, Sandu AV, Chirazi M, Honceriu C, Dabija RC, Vladescu A, Cotrut CM, Sandu I. The Role of Saline Aerosols in the Prevention and Therapy of Cardio-respiratory and Osteo-muscular Afflictions. Rev Chim 2018. [DOI: 10.37358/rc.18.10.6634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The saline aerosols generated in gaseous media, as nanodispersions, behave, with respect to the concentration levels and the lifespan, as trimodal distributions (the three domains with Gaussian distributions: fine or Aitken under 50 �m, medium between 50 and 500 mm and, respectively, coarse or large between 500 and 1000 mm). The generation in latent state is dependent on the active surface of the source (number of generator centres, the size and position of the fluorescences, the porosity, size and shape of the source, etc.), the climatic parameters, but also on a series of other characteristics of the gaseous medium. Our team has demonstrated experimentally that saline aerosols, NaCl type, besides the ability to prevent and treat broncho-respiratory and cardiac conditions, through coassistance of saline aerosols of other cations than sodium, and of the iodine anion, have for certain levels of concentrations propitious effects over the immune, bone and muscular systems. Similarly proved has been the positive influence on the development of children, as well the determinant role in increasing athletic performance and of other human subjects performing intense activities.
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Vladescu A, Mihai Cotrut C, Ak Azem F, Bramowicz M, Pana I, Braic V, Birlik I, Kiss A, Braic M, Abdulgader R, Booysen R, Kulesza S, Monsees TK. Sputtered Si and Mg doped hydroxyapatite for biomedical applications. Biomed Mater 2018; 13:025011. [DOI: 10.1088/1748-605x/aa9718] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Neacsu P, Staras AI, Voicu SI, Ionascu I, Soare T, Uzun S, Cojocaru VD, Pandele AM, Croitoru SM, Miculescu F, Cotrut CM, Dan I, Cimpean A. Characterization and In Vitro and In Vivo Assessment of a Novel Cellulose Acetate-Coated Mg-Based Alloy for Orthopedic Applications. Materials (Basel) 2017; 10:ma10070686. [PMID: 28773046 PMCID: PMC5551729 DOI: 10.3390/ma10070686] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [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: 04/26/2017] [Revised: 06/12/2017] [Accepted: 06/19/2017] [Indexed: 11/16/2022]
Abstract
Despite their good biocompatibility and adequate mechanical behavior, the main limitation of Mg alloys might be their high degradation rates in a physiological environment. In this study, a novel Mg-based alloy exhibiting an elastic modulus E = 42 GPa, Mg-1Ca-0.2Mn-0.6Zr, was synthesized and thermo-mechanically processed. In order to improve its performance as a temporary bone implant, a coating based on cellulose acetate (CA) was realized by using the dipping method. The formation of the polymer coating was demonstrated by FT-IR, XPS, SEM and corrosion behavior comparative analyses of both uncoated and CA-coated alloys. The potentiodynamic polarization test revealed that the CA coating significantly improved the corrosion resistance of the Mg alloy. Using a series of in vitro and in vivo experiments, the biocompatibility of both groups of biomaterials was assessed. In vitro experiments demonstrated that the media containing their extracts showed good cytocompatibility on MC3T3-E1 pre-osteoblasts in terms of cell adhesion and spreading, viability, proliferation and osteogenic differentiation. In vivo studies conducted in rats revealed that the intramedullary coated implant for fixation of femur fracture was more efficient in inducing bone regeneration than the uncoated one. In this manner, the present study suggests that the CA-coated Mg-based alloy holds promise for orthopedic aplications.
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Affiliation(s)
- Patricia Neacsu
- Department of Biochemistry and Molecular Biology, University of Bucharest, 91-95 Spl. Independentei, 050095 Bucharest, Romania.
| | - Adela Ioana Staras
- Department of Biochemistry and Molecular Biology, University of Bucharest, 91-95 Spl. Independentei, 050095 Bucharest, Romania.
| | - Stefan Ioan Voicu
- Department of Analytical Chemistry and Environmental Engineering, Politehnica University of Bucharest, 313 Spl. Independentei, 060042 Bucharest, Romania.
| | - Iuliana Ionascu
- Department of Clinical Sciences, University of Agricultural Sciences and Veterinary Medicine, 105 Spl. Independentei, 050097 Bucharest, Romania.
| | - Teodoru Soare
- Pathology Department, University of Agricultural Sciences and Veterinary Medicine, 105 Spl. Independentei, 050097 Bucharest, Romania.
| | - Seralp Uzun
- Department of Clinical Sciences, University of Agricultural Sciences and Veterinary Medicine, 105 Spl. Independentei, 050097 Bucharest, Romania.
| | - Vasile Danut Cojocaru
- Materials Processing Department, Politehnica University of Bucharest, 313 Spl. Independentei, 060042 Bucharest, Romania.
| | - Andreea Madalina Pandele
- Department of Analytical Chemistry and Environmental Engineering, Politehnica University of Bucharest, 313 Spl. Independentei, 060042 Bucharest, Romania.
| | - Sorin Mihai Croitoru
- Machines and Manufacturing Systems Department, Politehnica University of Bucharest, 313 Spl. Independentei, 060042 Bucharest, Romania.
| | - Florin Miculescu
- Department of Metallic Materials Science, Physical Metallurgy, Politehnica University of Bucharest, 313 Spl. Independentei, 060042 Bucharest, Romania.
| | - Cosmin Mihai Cotrut
- Department of Metallic Materials Science, Physical Metallurgy, Politehnica University of Bucharest, 313 Spl. Independentei, 060042 Bucharest, Romania.
- Experimental Physics Department, National Research Tomsk Polytechnic University, Lenin Avenue 43, 634050 Tomsk, Russia.
| | - Ioan Dan
- SC R&D Consulting and Services SRL, 45 Maria Ghiculeasa, 023761 Bucharest, Romania.
| | - Anisoara Cimpean
- Department of Biochemistry and Molecular Biology, University of Bucharest, 91-95 Spl. Independentei, 050095 Bucharest, Romania.
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Vladescu A, Kiss A, Braic M, Cotrut CM, Drob P, Balaceanu M, Vasilescu C, Braic V. Vacuum arc deposition of nanostructured multilayer coatings for biomedical applications. J Nanosci Nanotechnol 2008; 8:733-738. [PMID: 18464399 DOI: 10.1166/jnn.2008.d211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In recent years, the smart materials have attracted much attention due to their unusual properties such as shape memory effect and pseudoelasticity, being widely used for biomedical implants. These materials contain certain amounts of nickel, titanium and others which are not adequate for surgical implants and prosthesis. In the work reported here, two types of nonostructured multilayer coatings (TiN/ZrN, ZrN/Zr) used to prevent the ions release from shape memory alloys were investigated. For comparison, the TiN and ZrN monolayers were also examined. The films were deposited onto nickel-titanium based alloy (Ti-Ni-Nb) and Ni substrates by vacuum arc deposition technique under various deposition conditions. The concentrations of dissolved ions in Ringer solution for uncoated and coated Ni samples were determined to examine the benefic barrier effect of these coatings for ions release from shape memory alloys. In order to have a more complete characterization of the investigated coatings, other properties such as elemental and phase composition, morphology, texture, microhardness, and adhesion were studied. For all coatings, the concentrations of dissolved ions were lower that those measured in the case of the uncoated specimens. The nanostructured multilayer films exhibited the best mechanical and anticorrosive properties.
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Affiliation(s)
- A Vladescu
- National Institute for Optoelectronics-Tehnoprof Research Centre, Bucharest, 077125, Romania
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