Surface investigation of NiTi rotary endodontic instruments after magnetoelectropolishing

2009 ◽  
Vol 1244 ◽  
Author(s):  
Tadeusz Hryniewicz ◽  
Krzysztof Rokosz ◽  
Ryszard Rokicki
Keyword(s):  
Mechanical Properties ◽  
Photoelectron Spectroscopy ◽  
Surface Film ◽  
Surface Characteristics ◽  
Fatigue Tests ◽  
Digital Data ◽  
Maximum Height ◽  
Metallic State ◽  
Interferometric Method ◽  
Study Results

ABSTRACTThe purpose of the study was to reveal the effects of a new electropolishing process carried out under a constant magnetic field, termed as magnetoelectropolishing (MEP). In this work we investigated Nitinol rotary endodontic instruments by surface and morphology change after MEP. The MEP process greatly affects both surface also mechanical properties like the bending and fatigue resistance.The investigation covered surface interferometry measurements, X-ray Photoelectron Spectroscopy (XPS) studies, and Scanning Electron Microscopy (SEM) with EDAX studies referred to two groups of endodontic instruments: ready-to-use or as-received (AR) files, and magnetoelectropolished (MEP) instruments, in comparison with the instruments surface after a conventional electropolishing (EP). The treated surfaces of NiTi endodontic files were studied by interferometric method in view of getting multiple surface characteristics, together with digital data concerning the arithmetic mean height Sa and the maximum height of scale limited surface Sz.The investigation results obtained have indicated a considerable improvement of MEP surface in comparison with both AR and EP surfaces. Such a surface after MEP reveals several positive features, decreased roughness, elimination of metallic state (here Ni and Ti elements) in the surface film, much enriched with titanium oxides and diminished nickel oxides. The study results show that the contents of Ni compounds is higher after EP (18.3%) than after MEP (10.2%), whereas the contents of Ti compounds is higher after MEP (83.4%) than after EP (76.6%). The total Ti/Ni ratio indicates almost double surpass of titanium over nickel in the surface film after MEP in comparison with the total amount of that ratio after EP.The qualitative investigation of fatigue tests have indicated much better performance of NiTi endodontic file samples after MEP than those related to AR and/or after EP. We have proved that the magnetoelectropolishing process may further modify surface. The following studies are to be directed onto performance and specific mechanical properties of the endodontic files at work.

PEEK composites with polyimide sizing SCF as reinforcement: Preparation, characterization, and mechanical properties

2019 ◽  
Vol 32 (4) ◽  
pp. 383-393 ◽  
Author(s):  
Tao Wang ◽  
Yongsheng Jiao ◽  
Zhiming Mi ◽  
Jiantang Li ◽  
Daming Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Photoelectron Spectroscopy ◽  
Interfacial Adhesion ◽  
Surface Characteristics ◽  
Mechanical Analysis ◽  
Tensile Fracture ◽  
Polyether Ether Ketone ◽  
Engineering Plastics ◽  
Short Carbon ◽  
Good Agreement

In this work, the surface modification of short carbon fibers (SCFs) using polyimide (PI) as a sizing agent was conducted and fully characterized, and SCF-reinforced polyether ether ketone (PEEK) composites were obtained by extrusion and injection molding. The surface characteristics of the PI-coated SCFs were evaluated using scanning electron microscopy and X-ray photoelectron spectroscopy. The results indicated that a uniform PI sizing layer was formed on the surfaces of the SCFs. Thermogravimetric analysis results demonstrated that PI-coated SCFs had better thermal stability than commercial SCFs. The tensile strength and flexural strength of the PI-coated SCF/PEEK composites showed improvements of 11.8% and 16.6% compared with the commercial cases, which were attributed to the PI sizing treatment effectively improving the interfacial adhesion between the SCF and the PEEK matrix. Dynamic mechanical analysis and the morphologies of tensile fracture surfaces suggested better interfacial adhesion between the fibers and the PEEK matrix, which were in good agreement with the mechanical properties. Due to the convenient processing of PI sizing as well as the effectively improved mechanical properties of the composites, the PI-sizing methodology has great potential application in the field of fiber-reinforced high-temperature engineering plastics composites.

Influence of Oxygen Plasma Treatment on Impact Behaviors of Carbon Fibers-Reinforced Composites

2007 ◽  
Vol 119 ◽  
pp. 159-162 ◽  
Author(s):  
Soo Jin Park ◽  
Jin Seok Oh ◽  
Jae Rock Lee ◽  
Kyong Yop Rhee
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Carbon Fibers ◽  
Photoelectron Spectroscopy ◽  
Oxygen Plasma ◽  
Composite System ◽  
Surface Characteristics ◽  
Oxygen Plasma Treatment ◽  
Reinforced Composites ◽  
Ft Ir

In this work, effects of the oxygen plasma on surface characteristics of carbon fibers were investigated in impact strengths of the carbon fibers-reinforced composites. The surface properties of the carbon fibers were determined by acid-base values, FT-IR, and X-ray photoelectron spectroscopy (XPS). Also, the mechanical properties of the composites were studied in impact strength measurements. As experimental results, the O1S/C1S ratio of the carbon fiber surfaces treated by oxygen plasma was increased compared to that of untreated ones, possibly due to development of oxygen-containing functional groups. The mechanical properties of the composites, including impact strength had been improved in the oxygen plasma on fibers. These results indicate that the oxygen plasma can lead to an increase in the adhesion between fibers and matrix in a composite system.

Surface Characteristics and Corrosion Behavior of Ti-4Al-2V Alloy Implanted with Al and Nb

2007 ◽  
Vol 561-565 ◽  
pp. 2443-2446
Author(s):  
Y.Z. Liu ◽  
X.T. Zu ◽  
S.Y. Qiu ◽  
X.Q. Huang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Surface Film ◽  
Surface Characteristics ◽  
Tio2 Surface ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Β Phase ◽  
Glancing Angle

A Ti-Al-V alloy was implanted with Al and Nb to flounces ranging from 1 × 1017 to 1 × 1018 ions cm-2. Glancing Angle XRD measurement revealed α-Ti on Al-implanted samples and (α+β)-Ti on Nb-implanted samples. The (α+β)-phase samples exhibit better corrosion resistance. In the aerated solution with pH = 10, all the implanted surfaces are passive. Enhanced reoxidation was confirmed on implanted surfaces by Auger electron spectroscopy and X-ray photoelectron spectroscopy analysis. The corrosion in the solution with pH = 10 was governed predominantly by a TiO2 surface film.

scholarly journals Incorporation of Hybrid Nanomaterial in Dental Porcelains: Antimicrobial, Chemical, and Mechanical Properties

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 98
Author(s):  
Carla L. Vidal ◽  
Izabela Ferreira ◽  
Paulo S. Ferreira ◽  
Mariana L. C. Valente ◽  
Ana B. V. Teixeira ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Antimicrobial Activity ◽  
Biofilm Formation ◽  
Silver Ions ◽  
Surface Characteristics ◽  
Streptococcus Sobrinus ◽  
Hybrid Nanomaterial ◽  
Antimicrobial Substances ◽  
Health Area

Biofilm formation on biomaterials is a challenge in the health area. Antimicrobial substances based on nanomaterials have been proposed to solve this problem. The aim was to incorporate nanostructured silver vanadate decorated with silver nanoparticles (β-AgVO3) into dental porcelains (IPS Inline and Ex-3 Noritake), at concentrations of 2.5% and 5%, and evaluate the surface characteristics (by SEM/EDS), antimicrobial activity (against Streptococcus mutans, Streptococcus sobrinus, Aggregatibacter actinomycetemcomitans, and Pseudomonas aeruginosa), silver (Ag+) and vanadium (V4+/V5+) ions release, and mechanical properties (microhardness, roughness, and fracture toughness). The β-AgVO3 incorporation did not alter the porcelain’s components, reduced the S. mutans, S. sobrinus and A. actinomycetemcomitans viability, increased the fracture toughness of IPS Inline, the roughness for all groups, and did not affect the microhardness of the 5% group. Among all groups, IPS Inline 5% released more Ag+, and Ex-3 Noritake 2.5% released more V4+/V5+. It was concluded that the incorporation of β-AgVO3 into dental porcelains promoted antimicrobial activity against S. mutans, S. sobrinus, and A. actinomycetemcomitans (preventing biofilm formation), caused a higher release of vanadium than silver ions, and an adequate mechanical behavior was observed. However, the incorporation of β-AgVO3 did not reduce P. aeruginosa viability and increased the surface roughness of dental porcelains.

scholarly journals Pristine and Magnetic Kenaf Fiber Biochar for Cd2+ Adsorption from Aqueous Solution

2021 ◽  
Vol 18 (15) ◽  
pp. 7949
Author(s):  
Anwar Ameen Hezam Saeed ◽  
Noorfidza Yub Harun ◽  
Suriati Sufian ◽  
Muhammad Roil Bilad ◽  
Zaki Yamani Zakaria ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Textural Properties ◽  
Ion Concentration ◽  
Solution Temperature ◽  
Maximum Adsorption Capacity ◽  
Magnetic Biochar ◽  
X Ray ◽  
Study Results ◽  
Capacity Surface

Development of strategies for removing heavy metals from aquatic environments is in high demand. Cadmium is one of the most dangerous metals in the environment, even under extremely low quantities. In this study, kenaf and magnetic biochar composite were prepared for the adsorption of Cd2+. The synthesized biochar was characterized using (a vibrating-sample magnetometer VSM), Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The adsorption batch study was carried out to investigate the influence of pH, kinetics, isotherm, and thermodynamics on Cd2+ adsorption. The characterization results demonstrated that the biochar contained iron particles that help in improving the textural properties (i.e., surface area and pore volume), increasing the number of oxygen-containing groups, and forming inner-sphere complexes with oxygen-containing groups. The adsorption study results show that optimum adsorption was achieved under pH 5–6. An increase in initial ion concentration and solution temperature resulted in increased adsorption capacity. Surface modification of biochar using iron oxide for imposing magnetic property allowed for easy separation by external magnet and regeneration. The magnetic biochar composite also showed a higher affinity to Cd2+ than the pristine biochar. The adsorption data fit well with the pseudo-second-order and the Langmuir isotherm, with the maximum adsorption capacity of 47.90 mg/g.

Effect of toughened polyamide-coated carbon fiber fabric on the mechanical performance and fracture toughness of CFRP

2021 ◽  
pp. 002199832199945
Author(s):  
Jong H Eun ◽  
Bo K Choi ◽  
Sun M Sung ◽  
Min S Kim ◽  
Joon S Lee
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Photoelectron Spectroscopy ◽  
Mechanical Performance ◽  
Epoxy Composites ◽  
Scanning Calorimetry ◽  
Internal Damage ◽  
Impact Tests ◽  
Flexural Tests ◽  
The Impact

In this study, carbon/epoxy composites were manufactured by coating with a polyamide at different weight percentages (5 wt.%, 10 wt.%, 15 wt.%, and 20 wt.%) to improve their impact resistance and fracture toughness. The chemical reaction between the polyamide and epoxy resin were examined by fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray photoelectron spectroscopy. The mechanical properties and fracture toughness of the carbon/epoxy composites were analyzed. The mechanical properties of the carbon/epoxy composites, such as transverse flexural tests, longitudinal flexural tests, and impact tests, were investigated. After the impact tests, an ultrasonic C-scan was performed to reveal the internal damage area. The interlaminar fracture toughness of the carbon/epoxy composites was measured using a mode I test. The critical energy release rates were increased by 77% compared to the virgin carbon/epoxy composites. The surface morphology of the fractured surface was observed. The toughening mechanism of the carbon/epoxy composites was suggested based on the confirmed experimental data.

Effect of Hydrogen on Mechanical Properties of Pipeline API 5L X70 Steel

2011 ◽  
Vol 146 ◽  
pp. 213-225 ◽  
Author(s):  
T. Bellahcene ◽  
J. Capelle ◽  
Méziane Aberkane ◽  
Z. Azari
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Embrittlement ◽  
Hydrogen Absorption ◽  
Fatigue Tests ◽  
The Finite Element Method ◽  
Effective Distance ◽  
Bending Tests ◽  
Fatigue Initiation ◽  
Api 5L X70 Steel ◽  
Special Soil

The aim of this work is to study the effects of hydrogen absorption on mechanical properties of pipe API 5L X70 steel. This study is conducted in special soil solution NS4 with pH 6.7 It show that the tensile properties like yield stress, ultimate strength and elongation at failure reduced under hydrogen embrittlement. Several fatigue tests (three (03) points bending tests) on roman tile specimens with notch are performed. Fatigue initiation is detected by acoustic emission. A comparison between specimens electrolytically charged with hydrogen and specimens without hydrogen absorption is made and it has been noted that fatigue initiation time is reduced when hydrogen embrittlement occurs. The field of elastoplastic stresses near the notch is computed by the finite-element method with the Abaqus software package. Effective distance and stress are calculated with the volumetric approach and the Notch intensity Factor of the roman tile specimen is determined for each loading value used in our tests.

scholarly journals In Vitro Effect of Replicated Porous Polymeric Nano-MicroStructured Biointerfaces Characteristics on Macrophages Behavior

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1913
Author(s):  
Luminita Nicoleta Dumitrescu ◽  
Madalina Icriverzi ◽  
Anca Bonciu ◽  
Anca Roșeanu ◽  
Antoniu Moldovan ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Photoelectron Spectroscopy ◽  
Polyvinylidene Fluoride ◽  
Surface Characteristics ◽  
Sem Analysis ◽  
Chemical Structures ◽  
Microstructured Surface ◽  
Inflammatory Conditions ◽  
Vitro Effect

In the last decades, optimizing implant properties in terms of materials and biointerface characteristics represents one of the main quests in biomedical research. Modifying and engineering polyvinylidene fluoride (PVDF) as scaffolds becomes more and more attractive to multiples areas of bio-applications (e.g., bone or cochlear implants). Nevertheless, the acceptance of an implant is affected by its inflammatory potency caused by surface-induced modification. Therefore, in this work, three types of nano-micro squared wells like PVDF structures (i.e., reversed pyramidal shape with depths from 0.8 to 2.5 microns) were obtained by replication, and the influence of their characteristics on the inflammatory response of human macrophages was investigated in vitro. FTIR and X-ray photoelectron spectroscopy analysis confirmed the maintaining chemical structures of the replicated surfaces, while the topographical surface characteristics were evaluated by AFM and SEM analysis. Contact angle and surface energy analysis indicated a modification from superhydrophobicity of casted materials to moderate hydrophobicity based on the structure’s depth change. The effects induced by PVDF casted and micron-sized reversed pyramidal replicas on macrophages behavior were evaluated in normal and inflammatory conditions (lipopolysaccharide treatment) using colorimetric, microscopy, and ELISA methods. Our results demonstrate that the depth of the microstructured surface affects the activity of macrophages and that the modification of topography could influence both the hydrophobicity of the surface and the inflammatory response.

Cyclic Mechanical Properties of 16MnR Welded Joint under Constant

2011 ◽  
Vol 197-198 ◽  
pp. 1658-1661
Author(s):  
Ying Xiong ◽  
Han Ying Zheng
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Endurance Limit ◽  
Welded Joint ◽  
Cyclic Softening ◽  
Fatigue Tests ◽  
Test Results ◽  
Control Test ◽  
Strain Control ◽  
Fatigue Endurance

Fatigue tests are carried out for 16MnR welded joint under constant strain control. Test results reveal that 16MnR weld metal exhibits characteristic of cyclic softening and non-masing obviously. The strain–life curve can be best described by the three-parameter equation. It shows the fatigue endurance limit in the heat-affecting zone (HAZ) of welded joint is lower than that in the weld metal.

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