Mechanical Properties of Nanoceramic Zirconia Coatings on NiTi Orthodontic Wires

2016 ◽  
Vol 97 ◽  
pp. 147-152 ◽  
Author(s):  
Natalia Isabel de Azevedo Lopes ◽  
Leandro de Arruda Santos ◽  
Vicente Tadeu Lopes Buono
Keyword(s):  
Corrosion Resistance ◽  
Shape Memory ◽  
Mechanical Response ◽  
Crack Nucleation ◽  
Orthodontic Wires ◽  
Nickel Ions ◽  
X Ray ◽  
Three Point Bending ◽  
Force Microscopy ◽  
Niti Alloys

Nickel-titanium (NiTi) alloys have been largely applied in biomedical devices due to their special properties of superelasticity and shape memory. Even though NiTi generally displays good corrosion resistance and biocompatibility, mechanical fatigue and fretting-corrosion resistance remain important challenges in a number of applications, since it can accelerate nickel ions releasing, that have been reported as cytotoxic, mutagenic, and allergenic. This study aims to develop an appropriate coating to help delaying crack nucleation and corrosion in NiTi alloys. Zirconia (ZrO2) coating stands as a good candidate to improve the corrosion and wear resistance of metallic substrates and, in this work, it was obtained by electrodeposition on NiTi superelastic and shape memory orthodontic wires. The surface morphology and the chemical composition of the coated samples were evaluated using scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), and atomic force microscopy (AFM). The mechanical response was evaluated by three-point bending tests. The results showed that the ZrO2 layer was uniform and well adhered to the NiTi subtract. Additionally, it was observed that this coating was capable of undergoing severe deformation without cracking, indicating a potential increase in fatigue resistance of the conjugate.

Preparation and Research on the Lateral Elastic Modulus of the MnO2 Nanowires

2013 ◽  
Vol 662 ◽  
pp. 84-87
Author(s):  
Yong Jiang ◽  
Jian Cheng Deng ◽  
Yan Huai Ding ◽  
Jiu Ren Yin ◽  
Ping Zhang
Keyword(s):  
Elastic Modulus ◽  
Crystal Form ◽  
Bending Test ◽  
X Ray Diffraction ◽  
Nanowire Diameter ◽  
X Ray ◽  
Three Point Bending ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mno2 Nanowires

MnO2 nanowires with large aspect ratio were successfully synthesized via a hydrothermal method. In this method, Mn(NO3)2 was as a source of manganese and NH4NO3 as an oxidant. The structure and morphology of the MnO2 nanowires were characterized by X ray diffraction (XRD) and scanning electron microscope (SEM). Their lateral elastic modulus was characterized via a nanoscale three-point bending test by atomic force microscopy (AFM) equipped with picoforce. The results indicate that the crystal form of MnO2 was β-MnO2. The elastic modulus of the nanowires decreased with the increase in nanowire diameter. This elastic modulus was in the range of 33.36-77.84GPa as the diameter ranged from 240 to 185nm.

scholarly journals The Effect of Water Acrylate Dispersion on the Properties of Polymer-Carbon Nanotube Composites / Wpływ Wodnej Dyspersji Akrylanowej Na Właściwości Kompozytów Polimer-Nanorurki Węglowe

2015 ◽  
Vol 60 (4) ◽  
pp. 2715-2720
Author(s):  
P. Zygoń ◽  
M. Gwoździk ◽  
J. Peszke ◽  
Z. Nitkiewicz
Keyword(s):  
Carbon Nanotubes ◽  
Roughness Parameter ◽  
Composition Analysis ◽  
Phase Imaging ◽  
X Ray ◽  
Three Point Bending ◽  
Force Microscopy ◽  
Mode Method ◽  
Nanotube Composites ◽  
Crystallite Sizes

The paper presents properties of polymer composites reinforced with carbon nanotubes (CNT) containing various mixtures of dispersion. Acrylates of different particle size and viscosity were used to produce composites. The mechanical strength of composites was determined by three-point bending tests. The roughness parameter of composites was determined with a profilometer and compared with the roughness parameter determined via atomic force microscopy (AFM). Also X-ray studies (phase composition analysis, crystallite sizes determination) were carried out on these composites. Measurements of the surface topography using the Tapping Mode method were performed, acquiring the data on the height and on the phase imaging. The change of intensity, crystallite size and half-value width of main reflections originating from carbon within the composites have been determined using the X-ray analysis. The density of each obtained composite was determined as well as the resistivity at room temperature. The density of composites is quite satisfactory and ranges from 0.27 to 0.35 g/cm3. Different composites vary not only in strength but also in density. Different properties were achieved by the use of various dispersions. Carbon nanotubes constituting the reinforcement for a polymer composite improve the mechanical properties and conductivity composite.

In situ coupling of atomic force microscopy and sub-micrometer focused X-ray techniques

2014 ◽  
Vol 1712 ◽  
Author(s):  
Thomas W. Cornelius ◽  
Zhe Ren ◽  
Francesca Mastropietro ◽  
Simon Langlais ◽  
Anton Davydok ◽  
...  
Keyword(s):  
Mechanical Response ◽  
Elemental Distribution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Nanowires ◽  
Force Microscopy ◽  
Indentation Tests ◽  
Scanning Force ◽  
Diffraction Patterns

ABSTRACTA scanning force microscope for in situ nanofocused X-ray studies (SFINX) has been developed which can be installed on diffractometers at synchrotron beamlines allowing for the combination with various techniques such as coherent X-ray diffraction and fluorescence. The capabilities of this device are demonstrated on Cu nanowires and on Au islands grown on sapphire (0001). The sample topography, crystallinity, and elemental distribution of the same area are investigated by recording simultaneously an AFM image, a scanning X-ray diffraction map, and a fluorescence map. Additionally, the mechanical response of Au islands is studied by in situ indentation tests employing the AFM-tip and recording 2D X-ray diffraction patterns during mechanical loading.

scholarly journals Study on Fatigue Crack Nucleation of Electrodeposited Nanocrystalline Nickel

2008 ◽  
Vol 33-37 ◽  
pp. 925-930 ◽  
Author(s):  
Ji Jia Xie ◽  
Xiao Lei Wu ◽  
You Shi Hong
Keyword(s):  
Fatigue Crack ◽  
Maximum Stress ◽  
Fatigue Testing ◽  
Crack Nucleation ◽  
Sample Surface ◽  
Fatigue Crack Nucleation ◽  
Three Point Bending ◽  
Force Microscopy ◽  
Atomic Force ◽  
Average Size

The mechanism of fatigue crack nucleation for nanocrystalline (nc) nickel was experimentally investigated in this paper. The samples of electrodeposited nc nickel were loaded cyclically by using a three point bending instrument at first. Then, atomic force microscopy (AFM) was used to scanning the sample surface after fatigue testing. The results indicated that, after fatigue testing, there are vortex-like cells with an average size of 108nm appeared along the crack on nc nickel sample. And, the roughness of sample surface increased with the maximum stress at the surface

scholarly journals The Influence of Nitrogen Absorption on Microstructure, Properties and Cytotoxicity Assessment of 316L Stainless Steel Alloy Reinforced with Boron and Niobium

Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 506 ◽  
Author(s):  
Sadaqat Ali ◽  
Ahmad Majdi Abdul Rani ◽  
Riaz Ahmad Mufti ◽  
Farooq I. Azam ◽  
Sri Hastuty ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Photoelectron Spectroscopy ◽  
316L Stainless Steel ◽  
Artificial Saliva ◽  
Alloy System ◽  
Sample Surface ◽  
Nickel Ions ◽  
X Ray ◽  
Cytotoxicity Assessment

In the past, 316L stainless steel (SS) has been the material of choice for implant manufacturing. However, the leaching of nickel ions from the SS matrix limits its usefulness as an implant material. In this study, an efficient approach for controlling the leaching of ions and improving its properties is presented. The composition of SS was modified with the addition of boron and niobium, which was followed by sintering in nitrogen atmosphere for 8 h. The X-ray diffraction (XRD) results showed the formation of strong nitrides, indicating the diffusion of nitrogen into the SS matrix. The X-ray photoelectron spectroscopy (XPS) analysis revealed that a nitride layer was deposited on the sample surface, thereby helping to control the leaching of metal ions. The corrosion resistance of the alloy systems in artificial saliva solution indicated minimal weight loss, indicating improved corrosion resistance. The cytotoxicity assessment of the alloy system showed that the developed modified stainless steel alloys are compatible with living cells and can be used as implant materials.

Formation and Corrosion Behavior of Nickel/Alumina Nanocomposites

2020 ◽  
Vol 299 ◽  
pp. 100-106 ◽  
Author(s):  
D.I. Tishkevich ◽  
A.I. Vorobjova ◽  
Denis A. Vinnik
Keyword(s):  
Composite Material ◽  
Corrosion Resistance ◽  
Porous Alumina ◽  
Nanocomposite Materials ◽  
Alumina Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Potentiodynamic Polarization Curves

Ni nanopillars (Ni NPs) composite materials formation technology was presented. The morphological and structural properties of the composite material were investigated using scanning electron microscopy, atomic force microscopy, X-ray diffraction. The corrosion resistance of the nanocomposite materials has been studied by potentiodynamic polarization curves analysis. The composite represents the array of vertically ordered Ni NPs with the identical size in alumina matrix. XRD investigation indicates that Ni NPs are polynanocrystalline material. It has been shown that Ni NPs and the composite material have sufficient corrosion resistance in a 0.9% aqueous NaCl solution. Porous alumina matrix is the neutral and protective component of the composite. These nanocomposite materials can be excellent candidates for practical use in different applications.

Simulation of the Superelastic Response of SMA Orthodontic Wires

1998 ◽  
Vol 120 (5) ◽  
pp. 676-685 ◽  
Author(s):  
D. Raboud
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Mechanical Response ◽  
Numerical Solutions ◽  
Initial Value ◽  
Orthodontic Wires ◽  
Wide Range ◽  
Superelastic Behavior ◽  
Low Modulus ◽  
Experimental Works

Shape-memory alloys have properties that make them well suited to a variety of applications. One application for which their unique combination of properties (large elastic range, low modulus of elasticity, ability to deliver nearly constant forces over a wide range of deformations) seems ideally suited is for orthodontic retraction appliances where these properties are very desirable. The mechanical response of shape-memory alloys is modeled by a simple constitutive model that captures the essential superelastic behavior of the shape-memory wires. An initial value approach that iteratively converges to the appropriate boundary conditions is utilized to deliver numerical solutions. Qualitative agreement is shown with previous experimental works. The possible benefits of using such wires in an orthodontic retraction appliance are then investigated.

scholarly journals INVESTIGATION INTO THE STRUCTURE AND CORROSION RESISTANCE OF MG-AL AND MG-AL-ZR COATINGS PRODUCED BY MAGNETRON SPUTTERING / MAGNETRONINIŲ MG-AL, MG-AL-ZR IR ZR DANGŲ STRUKTŪROS IR KOROZINIO ATSPARUMO TYRIMAS

2012 ◽  
Vol 3 (6) ◽  
pp. 34-38
Author(s):  
Raimonda Lukauskaitė ◽  
Algirdas Vaclovas Valiulis
Keyword(s):  
Corrosion Resistance ◽  
Magnetron Sputtering ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
X Ray ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Zr Alloys

Thin cathode layers of 200 nm thickness of Mg-Al and Mg-Al-Zr alloys and pure Zr were formed on glass substrates using a magnetron sputtering technique. X-ray diffraction and atomic force microscopy were used for structure and morphology analysis of magnetron sputtered alloys. The corrosion resistance of the sputtered Mg-Al and Mg-Al-Zr coatings in 0.1 M (NH4)3BO3 and 0.1 M NaCl solution (pH = 8.6), was evaluated according to anodic polarization behavior. Santrauka Plonos, 1–2 μm storio, Mg-Al ir Mg-Al-Zr lydinių ir gryno Zr dangos buvo suformuotos ant stiklinių padėklų magnetroninio nusodinimo metodu. Šių dangų struktūra ir morfologija tirta fizikiniais analizės metodais: rentgeno spindulių difrakcija (toliau – RSD) ir atominės jėgos mikroskopija (toliau – AJM). Korozinis dangų atsparumas vertintas veikiant 0,1 M NH4BO3 ir 0,1 M NaCl tirpalu (pH = 8,6), be to, atlikti anodinės poliarizacijos tyrimai. Magnetroniniu būdu nusodintų dangų korozinis atsparumas lygintas su tradiciniais metalurginiais metodais pagamintų cirkonio ir Mg-Al lydinių koroziniu atsparumu. Nustatytos koreliacijos tarp lydinių struktūros ir korozinio atsparumo.

Oxidation and Corrosion Resistance of Nanocrystalline Copper Deposit Produced by Pulse Electrodeposition

2011 ◽  
Vol 264-265 ◽  
pp. 1519-1525 ◽  
Author(s):  
M. Saremi ◽  
M. Abouie
Keyword(s):  
Corrosion Resistance ◽  
Direct Current ◽  
Copper Deposit ◽  
Pulse Electrodeposition ◽  
Sulfate Electrolyte ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Oxidation And Corrosion

Pulse electrodeposition was used to produce nanocrystalline (nc) copper from copper sulfate electrolyte with saccharin as additive. The grain size of nanocrystalline coatings was determined using x-ray diffraction and atomic force microscopy (AFM) which was about 30 nm. Microcrystalline copper deposits were also produced by direct current electrodeposition processes and compared with pulse plated ones. Corrosion behavior of the coatings was investigated using polarization and Impedance measurements in different solutions. The oxidation test was carried out at 650°C in an electrical furnace. It was demonstrated that the nanocrystalline film was markedly superior to regularly grained films made by direct current (DC) plating; nanocrystalline deposits show higher corrosion resistance and much higher oxidation resistance.

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