scholarly journals Comparative Study of the Structure, Properties, and Corrosion Behavior of Sr-Containing Biocoatings on Mg0.8Ca

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1942 ◽  
Author(s):  
Mariya B. Sedelnikova ◽  
Yurii P. Sharkeev ◽  
Tatiana V. Tolkacheva ◽  
Margarita A. Khimich ◽  
Olga V. Bakina ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Corrosion Resistance ◽  
Comparative Analysis ◽  
Cell Viability ◽  
Corrosion Behavior ◽  
Current Density ◽  
Tricalcium Phosphate ◽  
Average Content ◽  
Structure Properties

A comparative analysis of the structure, properties and the corrosion behavior of the micro-arc coatings based on Sr-substituted hydroxyapatite (Sr-HA) and Sr-substituted tricalcium phosphate (Sr-TCP) deposited on Mg0.8Ca alloy substrates was performed. The current density during the formation of the Sr-HA coatings was higher than that for the Sr-TCP coatings. As a result, the Sr-HA coatings were thicker and had a greater surface roughness Ra than the Sr-TCP coatings. In addition, pore sizes of the Sr-HA were almost two times larger. The ratio (Ca + Sr + Mg)/P were equal 1.64 and 1.47 for Sr-HA and Sr-TCP coatings, respectively. Thus, it can be assumed that the composition of Sr-HA and Sr-TCP coatings was predominantly presented by (Sr,Mg)-substituted hydroxyapatite and (Sr,Mg)-substituted tricalcium phosphate. However, the average content of Sr was approximately the same for both types of the coatings and was equal to 1.8 at.%. The Sr-HA coatings were less soluble and had higher corrosion resistance than the Sr-TCP coatings. Cytotoxic tests in vitro demonstrated a higher cell viability after cultivation with extracts of the Sr-HA coatings.

Effects of hydroxyapatite content on mechanical properties and in-vitro corrosion behavior of ZK60/HA composites

2020 ◽  
Vol 111 (8) ◽  
pp. 621-631
Author(s):  
Jie Teng ◽  
Zili Xu ◽  
Jinlong Su ◽  
Yuan Li
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Electrochemical Measurement ◽  
X Ray Diffraction ◽  
Corrosion Morphology ◽  
Hardness Tests ◽  
Zk60 Alloy ◽  
Immersion Testing

Abstract In this study, hydroxyapatite-reinforced ZK60 Mg alloybased composites were fabricated via a powder metallurgy route. The mechanical properties of these composites were studied by compressive tests and hardness tests. The in-vitro corrosion behavior was also investigated using immersion testing and electrochemical measurement. The influence of hydroxyapatite content on the mechanical properties and invitro corrosion behavior was evaluated. The microstructure and corrosion morphology were characterized by means of X-ray diffraction, optical and scanning electron microscopy. The results showed that the composite materials with 10 wt.% hydroxyapatite exhibited a better combination of mechanical strength and corrosion resistance. Compared with ZK60 alloy, the addition of 10 wt.% hydroxyapatite resulted in an increase in corrosion resistance by 38.6%.

Study of Corrosion Behavior of Friction Surfacing AA6351 Aluminium Alloy Coating on AISI 1020 Low Carbon Steel

2020 ◽  
Vol 1012 ◽  
pp. 401-406
Author(s):  
Carlos Trivellato de Carvalho Filho ◽  
Pedro Paiva Brito
Keyword(s):  
Surface Roughness ◽  
Corrosion Resistance ◽  
Carbon Steel ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Alloy Coating ◽  
Low Carbon ◽  
Friction Surfacing ◽  
Finishing Process

In the present work, the friction surfacing process was applied to manufacture aluminum alloy (AA6351) coatings on low carbon steel (AISI 1020) substrates. After friction surfacing the AA6351 deposited coatings were submitted to two finishing process in order to adjust surface roughness: milling and milling followed by sanding. The corrosion behavior of the two finishing process was compared with the as-deposited condition in order to determine the influence of surface roughness on the corrosion resistance of friction surfacing coatings. The corrosion behavior was examined by electrochemical impedance spectroscopy and potentiodynamic polarization in a 3.5wt.%NaCl solution containing naturally dissolved O2. The results obtained indicated that the elevated surface roughness observed in the as-deposited condition led to relatively lower corrosion resistance in comparison, with lower values for polarization resistance and more anodic corrosion potential.

scholarly journals Corrosion Behavior of a WC/C Coated 7075-T6 Aluminum Alloy

2013 ◽  
Vol 577-578 ◽  
pp. 217-220
Author(s):  
Sergio Baragetti ◽  
M. Daurù ◽  
Riccardo Gerosa ◽  
Barbara Rivolta
Keyword(s):  
Surface Roughness ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Corrosion Behavior ◽  
Experimental Tests ◽  
Point Of View ◽  
Surface Finishing ◽  
Polished Surface ◽  
Foreign Object ◽  
Final Thickness

In the present experimental work, a WC/C coated 7075-T6 aluminum alloy was considered from the corrosion point of view. The coating was deposited by PVD technique with a final thickness of about 2.5μm. In order to study the influence of the coating on the corrosion behavior of the aluminum alloy, the samples surfaces were partially coated and the interface among the metal and the coating was analyzed after the corrosion tests described into the ASTM G110 standard. Such experimental plan was decided in order to simulate the possible in-service local removal of the thin and hard coating. This kind of damage, due for example to a foreign object impact, can occur because of the great hardness difference between the coating and the substrate. The experimental tests were carried out on samples with different surface finishing, ranging from about 0.02μm Ra (mirror-polished surface) to about 0.8μm Ra (320 grit paper). The aim of such choice was to investigate the effect of a surface roughness different from the optimal one (mirror polished) on the coating deposition. Moreover a different corrosion resistance is expected.

Effect of High-Intensity Pulsed Ion Beam Irradiation on the Electrochemical Corrosion Behavior of AZ31 Magnesium Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 571-574
Author(s):  
Peng Li
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Current Density ◽  
Ion Beam ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Open Circuit ◽  
Electrochemical Corrosion Behavior ◽  
Shot Number

HIPIB irradiation experiment is carried out at a specific ion current density of 1.1 J/cm2 with shot number from one to ten in order to explore the effect of shot number on electrochemical corrosion behavior of magnesium alloy. Surface morphologies, microstructure and corrosion resistance of the irradiated samples are examined by scanning electron microscopy (SEM), transmission electron microscope (TEM) and potentiodynamic polarization technique, respectively. It is found that HIPIB irradiation leads to the increase in open circuit potential, corrosion potential and breakdown potential, and the decrease in the corrosion current density and the corrosion rate as compared to the original sample. The improved corrosion resistance is mainly attributed to the grain refinement and surface purification induced by HIPIB irradiation.

scholarly journals Corrosion Resistance of Cr–Co Alloys Subjected to Porcelain Firing Heat Treatment—In Vitro Study

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 636
Author(s):  
Dorota Rylska ◽  
Bartłomiej Januszewicz ◽  
Grzegorz Sokołowski ◽  
Jerzy Sokołowski
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
In Vitro Study ◽  
Alloying Elements ◽  
Dental Ceramics ◽  
Cobalt Chromium ◽  
Corrosion Properties ◽  
Manufacturing Method

The procedure of ceramics fusion to cobalt–chromium (Co–Cr) base dental crowns affects their corrosion behavior and biological tolerance. This study’s purpose was to comparatively evaluate the effect of heat treatment (HT) applicable for dental ceramics firing on the corrosion properties among Co–Cr base alloys fabricated via different methods: casting (CST), milling soft metal and post sintering (MSM), and selective laser melting (SLM). All specimens were subjected to a heat treatment corresponding to a full firing schedule. The microstructure and elemental composition of oxidized surfaces were investigated by scanning electron microscopy and energy dispersive spectroscopy. Corrosion properties were examined by electrochemical potentiodynamic polarization tests. The values of jcorr, Ecorr, Rp, and breakdown potential Ebr were estimated. The oxide layers formed during the HT process corresponded to the composition of the original alloys’ structure. Among the thermal treated alloys, SLM showed the highest corrosion resistance, followed by the MSM and CST. This may be attributed to uniform distribution of alloying elements in homogenous structure and to the reduced porosity, which enhances corrosion resistance and decreases the risk of crevice corrosion. The overall corrosion behavior was strongly influenced by the segregation of alloying elements in the microstructure, thus, is directly determined by the manufacturing method.

Improvement of the Corrosion Resistance of NiTi Stents by Surface Treatments

1996 ◽  
Vol 459 ◽  
Author(s):  
C. Trépanier ◽  
M. Tabrizian ◽  
LH. Yahia ◽  
L. Bilodeau ◽  
D. L. Piron
Keyword(s):  
Corrosion Resistance ◽  
Oxide Layer ◽  
Corrosion Behavior ◽  
Surface Characteristics ◽  
Salt Bath ◽  
Surface Treatments ◽  
Nickel Titanium ◽  
Treatment Results ◽  
Porous Oxide

ABSTRACTBecause of its optimal radiopacity, superelasticity and shape memory properties Nickel-Titanium (NiTi) is an ideal material for the fabrication of stents. Indeed, these properties can facilitate the implantation and precise positioning of those devices. However, in vitro studies on NiTi report the dependency of the alloy biocompatibility and corrosion behavior to surface treatments. Oxidation of the surface seems to be very promising to improve both the corrosion resistance and the biocompatibility of NiTi. The present study investigate the effect of electropolishing, heat treatment (in air and in a salt bath) and nitric acid passivation to modify the oxide layer on NiTi stents. Techniques such as potentiodynamic polarization tests, Scanning Electron Microscopy (SEM) and Auger Electron Spectroscopy (AES) have been used to develop relationships between corrosion behavior, surface characteristics and surface treatment. Results show that all surface treatments improve the corrosion behavior of the alloy. SEM results indicate that treated stents which exhibit a smooth and uniform surface show a higher corrosion resistance than non treated stents which possess a very porous oxide layer. AES results, indicate that the best corrosion behavior was observed for the stents which exhibit the thinnest oxide layer (electropolished and passivated samples).

Comparative Analysis on Corrosion Behavior of 316SS and 304SS in Subcritical and Supercritical Aqueous Systems

2018 ◽  
Vol 777 ◽  
pp. 381-385
Author(s):  
Tong Tong Xu ◽  
Yan Hui Li
Keyword(s):  
Corrosion Resistance ◽  
Comparative Analysis ◽  
Corrosion Behavior ◽  
Chromium Concentration ◽  
Corrosion Products ◽  
Local Corrosion ◽  
Aqueous Systems ◽  
Industrial Sludge ◽  
Clay Materials

The corrosion characteristics of 316SS and 304SS in subcritical and supercritical aqueous systems including chloride of approximate 4600 mg/L at 25 MPa and 250 °C, 350 °C, 425 °C, and 520 °C are comparatively investigated. Some local corrosion areas occurred on the surfaces of SS316, not on that of 304SS, at 250 °C and 425 °C, while at 350 °C, all the sample surfaces were covered by large amounts of corrosion products and clay materials due to the predominant precipitation for the formation of the outer subscale. Whether in reducing subcritical and supercritical industrial sludge suspension or in oxidizing supercritical sludge system, 304SS owns better corrosion resistance than 316SS due to higher chromium concentration of former.

scholarly journals INFLUENCE OF ISOTHERMAL OXIDATION ON CORROSION RESISTANCE OF TITANIUM IN BOVINE SERUM

2018 ◽  
Vol 24 (1) ◽  
pp. 65
Author(s):  
Benidiktus Tulung Prayoga ◽  
Suyitno - Suyitno ◽  
Rini Dharmastiti
Keyword(s):  
Surface Roughness ◽  
Corrosion Resistance ◽  
Surface Properties ◽  
Corrosion Behavior ◽  
Bovine Serum ◽  
Isothermal Oxidation ◽  
Furnace Chamber ◽  
Surface Microhardness ◽  
Oxidation Treatment ◽  
Cp Ti

The thermal oxidation treatment is an innovative and simple method for modifiying the surface properties of titanium such as enhance corrosion and wear resistance. The effects of isothermal oxidation immersion time on the surface properties and corrosion behavior under bovine serum of cp-Ti were studied in this paper. The treatment was done at 700<sup>o</sup>C for 0 to 36 hours in furnace chamber. The surface microhardness, surface roughness, wettability and polarization potentiodynamic corrosion of cp-Ti were determined. The result shows the surface microhardness, surface roughness, wettability and corrosion resistance of the cp-Ti enhanced by isothermal oxidation treatment. The presence of the oxide layer on the surface in the form of TiO<sub>2</sub> rutile and Ti<sub>3</sub>O are responsible to enhance the surface properties and corrosion behavior

scholarly journals Corrosion Behavior of Diffusion Bonding Joints of (OFHC) Copper with Stainless Steel 304L in 3.5% NaCl

2018 ◽  
Vol 21 (1) ◽  
pp. 74
Author(s):  
Sami Abualnoun Ajeel ◽  
Ahmed Ali Akbar Akbar ◽  
Safaa Mohammed Hassoni
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Current Density ◽  
Diffusion Bonding ◽  
Corrosion Current Density ◽  
Pure Copper ◽  
Corrosion Current ◽  
Stainless Steel 304L ◽  
Materials Used

The present work deals with direct diffusion bonding welding without interlayer of austenitic stainless steel type AISI 304L with Oxygen Free High Conductivity pure copper (OFHC) in vacuum atmosphere (1.5 *10-5 mbr.). The optimum bonding conditions are temperature of 650 ◦C, duration time of 45 min. and the applied stress of 30 MPa, in order to secure a tight contact between the mating surfaces. The corrosion behavior of diffusion bonding joints in 3.5% Nacl is studied to evaluate the corrosion resistance of welding joints by using Potentiodynamic method. The observed microstructure of corroded specimen of optimum diffusion bonding joint shows that the corrosion current density has low value as compared with base materials used. During polarization, galvanic coupling is observed between two materials used. At passivity region, inverse polarity is occurred at 450mV. Therefore, passive stainless steel 304 L behaves as cathode respective to pure copper, the corrosion behavior of the diffusion bonding joint was mostly by copper side. The corrosion results indicate the presence of galvanic effect. The corrosion current density of copper, stainless steel 304L and bond joints condition were (3.66 µA/cm2, 1.62 µA/cm2 and 1.85µA/cm2) respectively. A SEM examination of corroded diffusion bonding joint indicates that the galvanic corrosion happened on copper side. The corrosion rate of bonding joint conditions was 0.85 mpy, which is less than 1%. This means that corrosion resistance of bond joint is more than excellent.

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