The effect of TiO2 coating on biological NiTi alloys after micro-arc oxidation treatment for corrosion resistance

Author(s):  
Ebru Emine Sukuroglu ◽  
Suleyman Sukuroglu ◽  
Kubra Akar ◽  
Yasar Totik ◽  
Ihsan Efeoglu ◽  
...  

NiTi alloys exhibit good properties, such as shape memory behavior, high corrosion resistant, having the closest elasticity modulus of a human bone and superior biocompatibility properties. However, the surface problems that arise during the use of this alloy limit the usage in the industry and health sector. In recent years, micro-arc oxidation method is used to improve the surface properties and increase the usage of these alloys. In this study, the TiO2 coatings were deposited on the NiTi substrates. The surface topography, morphology, crystallographic structure, and thickness of the coatings were determined using scanning electron microscopy and X-ray diffraction. The corrosion properties were investigated using potentiostat test unit in two different media such as NaCl solution and simulated body fluid. The results show that the coated samples have higher corrosion resistance than uncoated samples in the two different media.

2014 ◽  
Vol 12 (11) ◽  
pp. 1183-1193 ◽  
Author(s):  
Vassil Bachvarov ◽  
Miglena Peshova ◽  
Stefana Vitkova ◽  
Nikolai Boshkov

AbstractThe presented work reports on the peculiarities of the anodic behavior, corrosion resistance and protective ability of electrodeposited Zn-Ni-P alloys with a different composition in a model corrosion medium of 5% NaCl. Three characteristic coating types have been investigated using experimental methods such as potentiodynamic polarization (PD) technique and polarization resistance (Rp) measurements. In addition, X-ray diffraction (XRD) analysis as well as scanning electron microscopy (SEM) coupled with an Energy-dispersive X-ray (EDAX) device were applied to determine the differences in the chemical composition and surface morphology which appeared as a result of the corrosion treatment. The data obtained are compared to those of electrodeposited pure Zn coatings with identical experimental conditions demonstrating the enhanced protective characteristics of the ternary alloys during the test period in the model medium. The influence of the chemical and phase composition of the alloys on its corrosion resistance and protective ability is also commented and discussed.


2010 ◽  
Vol 434-435 ◽  
pp. 634-637 ◽  
Author(s):  
Pu Liang Zhang ◽  
Bin Liu ◽  
Dong Zhang ◽  
Yong Wei Tao ◽  
Sheng Rong Yang ◽  
...  

Ceramic coatings were produced on magnesium (Mg) alloy of AZ91D for biomaterial applications by micro-arc oxidation (MAO) and electrodeposition methods. The morphology, microstructure, phase composition and corrosion properties of the prepared coatings were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and potentiodynamic polarization tester, etc. The results indicated that a porous oxide layer was grown on the Mg alloy sheets after MAO process and the compositions of oxides were mainly Mg2SiO4 and MgO. After further electrodeposition and alkaline treatment, a flake-like structure diverging from centre to periphery was grown on the MAO coating and the coating was mainly made up of hydroxyapatite (HA). Moreover, the corrosion resistance of the Mg alloy after being treated with MAO and electrodeposition technique increases obviously, which was evaluated in stimulated body fluid (SBF).


Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2647
Author(s):  
Madiha Ahmed ◽  
Yuming Qi ◽  
Longlong Zhang ◽  
Yanxia Yang ◽  
Asim Abas ◽  
...  

The objectives of this study were to reduce the corrosion rate and increase the cytocompatibility of AZ31 Mg alloy. Two coatings were considered. One coating contained MgO (MAO/AZ31). The other coating contained Cu2+ (Cu/MAO/AZ31), and it was produced on the AZ31 Mg alloy via microarc oxidation (MAO). Coating characterization was conducted using a set of methods, including scanning electron microscopy, energy-dispersive spectrometry, X-ray photoelectron spectroscopy, and X-ray diffraction. Corrosion properties were investigated through an electrochemical test, and a H2 evolution measurement. The AZ31 Mg alloy with the Cu2+-containing coating showed an improved and more stable corrosion resistance compared with the MgO-containing coating and AZ31 Mg alloy specimen. Cell morphology observation and cytotoxicity test via Cell Counting Kit-8 assay showed that the Cu2+-containing coating enhanced the proliferation of L-929 cells and did not induce a toxic effect, thus resulting in excellent cytocompatibility and biological activity. In summary, adding Cu ions to MAO coating improved the corrosion resistance and cytocompatibility of the coating.


Author(s):  
Bo Xu ◽  
Yafeng He ◽  
Xiangzhi Wang ◽  
Weimin Gan

Abstract Ceramic coatings were prepared on the surface of 7050 highstrength aluminum alloy using micro-arc oxidation in an aluminate electrolyte with added graphene. To analyze the surface morphology, roughness, phase composition, and corrosion resistance, scanning electron microscopy, X-ray diffraction, X-ray photoelectron, and electrochemical measurements were used, respectively. The addition of 9 g · L-1 of graphene to the electrolyte decreased the micro-pore size of the composite coatings and improved the density. In addition, with the addition of graphene, the roughness was the lowest, and the corrosion resistance was significantly improved.


Author(s):  
Yu Zong ◽  
Renguo Song ◽  
Tianshun Hua ◽  
Siwei Cai

Abstract In this paper, ceramic coatings were prepared on the surface of 7050 high strength aluminum alloy using a micro-arc oxidation process in a silicate electrolyte combined with the rare earth element cerium or graphene. To analyze the surface morphology, roughness, phase composition, and corrosion resistance, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectrometry, and electrochemical measurements were used, respectively. It was shown that the micropore size of the composite coatings, which mainly consisted of α-Al2O3 and γ-Al2O3, decreases and the density improved with the simultaneous addition of 4 g · L-1 of CeO2 and 10 g · L-1 of graphene to the electrolyte. In addition, with the addition of CeO2 and graphene, the roughness was the lowest and the corrosion resistance was significantly improved.


2010 ◽  
Vol 636-637 ◽  
pp. 1042-1046
Author(s):  
Magdalena Popczyk ◽  
Antoni Budniok

Zn-Ni and Zn-Ni-W coatings were prepared by the electrodeposition under the galvanostatic conditions (jdep. = -0.020 A cm-2) from the zinc bath containing additionally ions of nickel (Zn-Ni) and ions of nickel and tungsten (Zn-Ni-W). The Zn-Ni coating after electrodeposition was subjected to outside passivation and in the Zn-Ni-W coating the passive function performs tungsten (inside passivation). The surface morphology of the coatings was studied using a scanning electron microscope (JEOL JSM - 6480). Chemical composition of obtained coatings was determined by the X-ray fluorescence spectroscopy (XRF). Phase composition investigations were conducted by X-ray diffraction method using a Philips diffractometer. Electrochemical corrosion resistance investigations were carried out in the 3% NaCl, using potentiodynamic and electrochemical impedance spectroscopy (EIS) methods. On the basis of these investigations it was found that Zn-Ni coating is more corrosion resistant than the Zn-Ni-W coating.


2013 ◽  
Vol 456 ◽  
pp. 438-441 ◽  
Author(s):  
Tian Yang ◽  
Cheng Zhang Peng ◽  
Lang Xiang ◽  
Huo Cao

The electroplated Ni-Co-Cr coatings were prepared on surface of a low carbon steel. The microstructure of the deposits were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD), the corrosion resistance of the deposits was evaluated using neutral salt-spray test and polarization measurement. The results show that the deposits are a Co and Cr solid solution in Ni with a grain size of 6.9~10.6nm, were nearly free of corrosion after neutral salt-spray tested 100 hours. With chromium content increasing, the coatings exhibited higher corrosion potential and lower corrosion current, which revealed excellent corrosion resistance.


2011 ◽  
Vol 471-472 ◽  
pp. 203-208
Author(s):  
Arman Zarebidaki ◽  
Saeed Reza Allahkaram

Ni-P/nano- SiC composite coatings were deposited in different concentrations of SiC nano-particles in the bath. The hardness and corrosion resistance of the composite coatings with different content of SiC nano-particles were measured. Moreover, the structure of the composite coatings was investigated by means of X-ray diffraction (XRD), while their morphologies and elemental composition were analyzed using scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS). Results showed that co-deposited SiC nano-particles contributed to increase the hardness but corrosion resistance of electroless Ni-P coatings decreased due to agglomeration of nano-particles and increasing porosity of coatings.


2019 ◽  
Vol 69 (12) ◽  
pp. 3490-3493
Author(s):  
Elisabeta Coaca ◽  
Alexandru Marin ◽  
Oana Rusu ◽  
Viorel Malinovschi ◽  
Victor Andrei

Anticorrosion layers were prepared on commercial Zr-2.5%Nb alloy by employing plasma electrolytic oxidation (PEO) process in aqueous electrolyte solutions. Microstructure and electrochemical behavior were evaluated using X-ray diffraction (XRD), optical metallography and potentiodynamic polarization measurements. The obtained coatings are uneven, presenting a dominant monoclinic crystallographic phase of ZrO2. Enhanced corrosion resistance was attributed to the PEO-treated samples compared to the commercial black oxide coating.


2016 ◽  
Vol 24 (01) ◽  
pp. 1750012 ◽  
Author(s):  
ZHONGCAI SHAO ◽  
FEIFEI ZHANG ◽  
QINGFANG ZHANG ◽  
LI YANG ◽  
XIAOYI SHEN

The grayish black film was prepared on AM50 magnesium alloy with a new method which combined chemical conversion with micro-arc oxidation (MAO). The optimum formula of chemical conversion was obtained by L9(34) orthogonal test. Meanwhile, the morphology, structure, composition and corrosion resistance of films were analyzed by scanning electron microscopy (SEM), energy spectrum analysis (energy dispersive X-ray spectroscopy (EDS)), X-ray diffraction (XRD), electrochemical tests and CuSO4 drip experiment. The results indicated that Mo element was introduced into the MAO film by chemical conversion pretreatment. The surface of composite film was smooth and compact. The main phase composition of the composite film were SiO2, Mo9O[Formula: see text], MgSiO[Formula: see text] Mg2SiO4 and Mo9O[Formula: see text] was identified to be responsible for giving color to the film. The corrosion resistance of the grayish black film was improved obviously.


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