scholarly journals Effect of Argon-Oxygen Mixing Gas during Magnetron Sputtering on TiO2 Coatings

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
N. Madaoui ◽  
L. Bait ◽  
K. Kheyar ◽  
N. Saoula

A reactive r.f magnetron sputtering method was used to deposit titanium dioxide coating on stainless steel substrates without intentional heating or biasing. The purpose of this work is given to study the argon-oxygen mixing gas on the corrosion behavior of TiO2 coatings. The morphology and structure of the coatings were studied by X-ray diffraction (XRD). Potentiodynamic polarization was used to study the corrosion behavior of the coatings. The results obtained from potentiodynamic polarization curves showed that TiO2 coatings possessed higher corrosion resistance than uncoated substrate.

2012 ◽  
Vol 557-559 ◽  
pp. 1768-1771
Author(s):  
Xiao Bing Zhao ◽  
Zhi Hui Ye

Fe-based amorphous coating was prepared on stainless steel substrates by atmospheric plasma spraying (APS) using Fe-based amorphous powder as feedstock. Microstructures of the coating were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM). The corrosion behavior of coating and stainless steel were evaluated respectively in 3.5% NaCl, 10% NaOH and 1 mol/L H2SO4 aqueous solutions by electrochemical workstation. The results indicated that the coating was composed of most amorphous phase and some Fe-Cr crystalline phase. The coating exhibited the better corrosion resistance in H2SO4 solution, while the worse in NaOH.


2011 ◽  
Vol 686 ◽  
pp. 641-645
Author(s):  
Jun Liu ◽  
Wei Ling Lv ◽  
Tao Tang ◽  
Si Xiang Zhao ◽  
Rong Lei ◽  
...  

The yttria-erbia multilayered coatings were prepared on 316L stainless steel substrates by bipolar pulse magnetron sputtering. Structures of these coatings were examined by X-ray diffraction and scanning electron microscopy. Bonding strength of these coatings on 316L stainless steel substrates was measured by scratch tester. Nano-hardness of these coatings was measured by nano-indenter. Comparative studies of the mechanical properties of the single-layered yttria coatings and multilayered coatings were conducted, and the seven layered coatings presented the highest bonding strength and nano-hardness as well as elastic modulus.


Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1042
Author(s):  
Panneer Selvam Kevin ◽  
Abhishek Tiwari ◽  
Saravanan Seman ◽  
Syed Ali Beer Mohamed ◽  
Rengaswamy Jayaganthan

Cr3C2–NiCr coatings have been used extensively to combat the erosion corrosion of hydro power turbine blades made of stainless steel. Cr3C2–NiCr coatings are also used in aqueous corrosive environments due to the high corrosion resistance rendered by the NiCr binder. In this investigation, both erosion and corrosion environments are introduced to cermet coating to study corrosion behavior using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The cermet coatings are useful for reducing the risk of deterioration of mechanical properties of hydro power turbines due to the continuous exposure to the erosive and corrosive action of the corrosive environment containing silt. It was observed that Cr3C2–NiCr coating offered a reasonable improvement in corrosion resistance when compared to bare substrate. The corrosion behavior of the coating was studied in a 150 mL solution of 0.1 M NaCl with 2 gms of quartz particles (0.2–0.8 mm) at various rotation speeds (3000, 4500, 6000 rpm) of the solution over a 1 h immersion using potentiodynamic polarization and EIS studies in a specifically designed experimental set-up for erosion corrosion. When compared to the bare stainless steel samples at 3000 rpm and 6000 rpm, the coating showed the highest improvement at 6.57 times and the least improvement at 3.79 times, respectively.


Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 636 ◽  
Author(s):  
Xu ◽  
Wang ◽  
Chen ◽  
Qiao ◽  
Zhang ◽  
...  

The effect of rare earth oxides on the microstructure and corrosion behavior of laser-cladding coating on 316L stainless steel was investigated using hardness measurements, a polarization curve, electrochemical impedance spectroscopy (EIS), a salt spray test, X-ray diffraction, optical microscopy, and scanning electron microscopy (SEM). The results showed that the modification of rare earth oxides on the laser-cladding layer caused minor changes to its composition but refined the grains, leading to an increase in hardness. Electrochemical and salt spray studies indicated that the corrosion resistance of the 316L stainless steel could be improved by laser cladding, especially when rare earth oxides (i.e., CeO2 and La2O3) were added as a modifier.


2011 ◽  
Vol 686 ◽  
pp. 589-594 ◽  
Author(s):  
Sheng Lu ◽  
Liang Wen Wu ◽  
Jing Chen

By means of reaction magnetron sputtering, TiAlN ternary compound films were deposited on AZ91D magnesium alloy substrates. The influence of partial pressure ratio of N2 to Ar (N2/Ar) on the microstructure and properties of TiAlN film was explored with scanning electron microscopy (SEM), X-ray diffraction (XRD), and tests of microhardness, hydrophile and corrosion resistance. The results show that with the increase of N2/Ar partial pressure ratio from 0.5:10 to 1.5:10, Ti2N becomes the main film phase and the size of the crystals cluster decreases. As the N2/Ar ratio is as higher as 2:10, the film crystals change from Ti2N to TiN with coarse clusters. With increase of N2/Ar rate, the hardness, hydrophobic nature and corrosion resistance of the TiAlN film tend to increase.


2015 ◽  
Vol 62 (3) ◽  
pp. 163-171 ◽  
Author(s):  
Yinhui Yang ◽  
Biao Yan

Purpose – The aim of this paper was to investigate the effect of strain rate on microstructure and corrosion behavior of 2205 duplex stainless steel, after high-temperature compression tests. Design/methodology/approach – The specimens were prepared using a Gleeble3800 thermo-simulation machine over a range of temperatures from 850 to 1,250°C and strain rates from 0.005 to 5 s−1, and the corresponding flow curves and deformation microstructure obtained were further analyzed. To evaluate the effect of strain rate on corrosion behavior, potentiodynamic polarization tests and double-loop electrochemical potentiodynamic reactivation (DL-EPR) were used to characterize the electrochemical performance. Findings – Compared with strain rate of 0.5 s−1, the worst corrosion resistance behavior from the potentiodynamic polarization test results after deformation at 0.005 s−1 was attributed to more austenite (γ) and ferrite (δ) grain boundaries or δ/γ phase interface formation due to the better effect of γ dynamic recrystallization (DRX) or δ dynamic recovery (DRV). Increasing strain rate to 5 s−1 lowered the corrosion resistance, due to the increase in dislocation density. At the low strain rate of 0.005 s−1, the susceptibility to intergranular corrosion (IGC) was comparatively high after deformation at 1050 and 1150°C with more γ/γ grains and δ/γ phase boundary formation, which was lowered with the strain rate increase to 0.5 s−1, due to suppressing effect of γ DRX. Originality/value – The paper provides the scientific basis for the practical application of hot working of 2205 duplex stainless steel.


Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7389
Author(s):  
Michael Kahl ◽  
Teresa D. Golden

Modified zaccagnaite layered double hydroxide (LDH) type films were synthesized on steel substrates by pulsed electrochemical deposition from aqueous solutions. The resulting films were characterized by X-ray diffraction, scanning electron microscopy/X-ray dispersive spectroscopy, and Fourier transform infrared spectroscopy. Structural characterization indicated a pure layered double hydroxide phase; however, elemental analysis revealed that the surface of the films contained Zn:Al ratios outside the typical ranges of layered double hydroxides. Layer thickness for the deposited films ranged from approximately 0.4 to 3.0 μm. The corrosion resistance of the film was determined using potentiodynamic polarization experiments in 3.5 wt.% NaCl solution. The corrosion current density for the coatings was reduced by 82% and the corrosion potential was shifted 126 mV more positive when 5 layers of modified LDH coatings were deposited onto the steel substrates. A mechanism was proposed for the corroding reactions at the coating.


2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Yanxin Qiao ◽  
Jie Huang ◽  
Ding Huang ◽  
Jian Chen ◽  
Wen Liu ◽  
...  

The effects of laser scanning speed on the microstructure, microhardness, and corrosion behavior of Ni45 coatings were investigated by using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), microhardness, and electrochemical measurements. The results showed that increasing laser scanning speed promotes the transformation from planar crystals to dendrites and refines the grains concurrently. The γ-(Ni, Fe), FeNi3, and M23(C,B)6 are identified as the primary phase composition in the Ni45 coatings regardless of the laser scanning speed. Thereinto, the formation and growth of M23(C,B)6 precipitates can be inhibited with increasing laser scanning speed due to the higher cooling rate, which affects the microhardness distribution and corrosion resistance of the coating. On the one hand, the microhardness of the whole coating presents a downtrend with increasing laser scanning speed due to the reduction of M23(C,B)6 phase. On the other hand, the corrosion resistance in 0.5 M NaCl solution is improved to some extent at higher laser scanning speed because the less precipitation of M23(C,B)6 reduces the depletion of Cr around the precipitates. In contrast, all the coatings exhibit undifferentiated but poor corrosion resistance in the highly corrosive 0.5 M NaCl + 0.5 M H2SO4 solution.


2015 ◽  
Vol 1125 ◽  
pp. 441-444 ◽  
Author(s):  
Mahtab Assadian ◽  
Mohd Hasbullah Idris ◽  
Mohammad Mahdi Taheri ◽  
Mostafa Rezazadeh Shirdar ◽  
Davood Almasi

Corrosion behavior of Magnesium substrate were investigated after NaOH treatment in different concentrations (1, 5, and 10 Molar) and duration of (10 min, 30 min, 1 h, 3 h, 6 h and 24 h) at room temperature to be utilized in biomaterial application. Creation of Mg(OH)2 barrier layer after treatment enhanced corrosion resistance. X-Ray diffraction (XRD) was conducted to detect the existence of barrier layer. Potentiodynamic polarization and immersion tests were evaluated the corrosion behavior of Magnesium in Kokubo simulated body fluid (SBF). It is found that Magnesium treated by 1M NaOH for 30 min reveals higher corrosion resistance. In addition this investigation indicates that pH value of Kokubo SBF, strongly influenced by different time and concentration of alkaline treatment


2012 ◽  
Vol 1449 ◽  
Author(s):  
Chen Zhao ◽  
Dan Jiang ◽  
Shundong Bu ◽  
Jinrong Cheng

ABSTRACTFerroelectric 0.7BiFeO3-0.3PbTiO3 (BFO-PT) films were deposited on stainless steel substrates by the sol-gel method. A thin layer of PbTiO3 (PT) was introduced between the substrates and BFO-PT films in order to decrease the annealing temperature of BFO-PT films. X-ray diffraction analysis reveals that BFO-PT films could be well crystallized into the perovskite structure at about 575 oC. Scanning electron microscope (SEM) images show that BFO-PT thin films have grain size of about 50∼60 nm. Our results indicated BFO-PT films deposited on stainless steel substrates maintained the excellent ferroelectric properties with remnant polarization of about 40∼50 μC/cm2.


Sign in / Sign up

Export Citation Format

Share Document