Microstructure and Corrosion Resistance of Fe-Based Amorphous Coating Prepared Atmospheric Plasma Spraying

2012 ◽  
Vol 557-559 ◽  
pp. 1768-1771
Author(s):  
Xiao Bing Zhao ◽  
Zhi Hui Ye
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Plasma Spraying ◽  
Amorphous Powder ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Amorphous Coating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Steel Substrates

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.

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
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Magnetron Sputtering ◽  
Corrosion Behavior ◽  
Potentiodynamic Polarization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Potentiodynamic Polarization Curves ◽  
Morphology And Structure ◽  
Steel Substrates

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.

Ablation Behavior of HfC Coating Prepared by Supersonic Plasma Spraying for SiC-Coated C/C Composites

2015 ◽  
Vol 24 (5) ◽  
pp. 096369351502400 ◽  
Author(s):  
Yang Yang ◽  
Kezhi Li ◽  
Hejun Li
Keyword(s):  
Plasma Spraying ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
X Ray Diffraction ◽  
Dense Structure ◽  
X Ray ◽  
Ablation Resistance ◽  
Supersonic Plasma ◽  
Centre Region ◽  
Supersonic Atmospheric Plasma Spraying

In order to improve the ablation resistance of C/C composites HfC coating was deposited on the surface of SiC-coated C/C composites by supersonic atmospheric plasma spraying. The microstructure and morphology of the different coatings were characterized by Scanning Electron Microscopy, X-ray diffraction. The ablation test of samples was carried out with an oxyacetylene torch. The coating exhibits dense structure and good ablation resistance. After ablation for 30s, the linear and mass ablation rates of the coating are 0.59 μm/s and 0.6 mg/s, respectively. In ablation centre region, a HfO2 layer is formed on the surface of sample after 30s ablation, and it can protect C/C composites from ablation.

scholarly journals Ablation mechanism and morphology evolution of the HfC-SiC coating for C/C composites deposited by supersonic atmospheric plasma spraying

2019 ◽  
Vol 28 ◽  
pp. 096369351986994 ◽  
Author(s):  
Yang Yang ◽  
Kezhi Li ◽  
Chun Zhao
Keyword(s):  
Plasma Spraying ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Carbon Composites ◽  
X Ray Diffraction ◽  
Ablation Resistance ◽  
Ablation Mechanism ◽  
Coated Carbon ◽  
Supersonic Atmospheric Plasma Spraying ◽  
New Phase

HfC-SiC protective coating was deposited on the surface of SiC-coated carbon/carbon composites by supersonic atmospheric plasma spraying due to the high arc temperature and the efficient deposition rate. The morphology and microstructure of the HfC-SiC coating were analyzed by X-ray diffraction and scanning electron microscopy. The results showed that Hf and Si elements distributed uniformly in the coating and the coating was dense without crack. Ablation resistance test was processed by oxyacetylene torch. During the ablation process, the sintering rate of HfO2 was slow, and more oxygen diffused into the internal coating, which caused the oxidation of the internal coating and damaged the structure of internal coating in the ablation center region. In addition, during cooling process, a new phase HfSiO4 was generated by the reaction between HfO2 and SiO2, which acted as a pinning agent to prevent the further expansion of the crack.

scholarly journals Investigations of microstructure and selected mechanical properties of Al2O3 + 40 wt.% TiO2 coatings deposited by Atmospheric Plasma Spraying (APS)

2019 ◽  
Vol 91 (8) ◽  
pp. 7-11 ◽  
Author(s):  
Monika Michalak ◽  
Leszek Łatka ◽  
Paweł Sokołowski ◽  
Andrzej Ambroziak
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Plasma Spraying ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Good Adhesion ◽  
Spraying Parameters ◽  
Tio2 Coatings

Atmospheric Plasma Spraying (APS) enables deposition of coatings from different materials, including those based on Al2O3 and TiO2. In this work, Al2O3 + 40 wt.% TiO2 coatings were tested. The relationships between mechanical properties, microstructure and spraying parameters (namely: spraying distance and torch scan velocity) were investigated. Commercial -45 + 5 μm powders in agglomerated as- produced state were sprayed onto the stainless steel 1.4301 substrates. The aim of the study was to determine the adhesion, microhardness and roughness of coatings but also to characterize their microstructure. It was observed that coatings sprayed from shorter distance were well melted and revealed good adhesion, but at the same time they were more porous and of lower microhardness than those deposited from the longer spraying distance.

scholarly journals Corrosion Resistance of Electrochemically Synthesized Modified Zaccagnaite LDH-Type Films on Steel Substrates

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7389
Author(s):  
Michael Kahl ◽  
Teresa D. Golden
Keyword(s):  
Corrosion Resistance ◽  
Layered Double Hydroxide ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
X Ray Diffraction ◽  
X Ray ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Steel Substrates ◽  
Deposited Films

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.

scholarly journals The possibilities of atmospheric plasma-spraying application to obtain hydroxyapatite coatings on the stainless steel samples

2013 ◽  
Vol 67 (5) ◽  
pp. 753-757
Author(s):  
Marija Mihailovic ◽  
Aleksandra Pataric ◽  
Zvonko Gulisija ◽  
Zoran Janjusevic ◽  
Miroslav Sokic
Keyword(s):  
Stainless Steel ◽  
Plasma Spraying ◽  
Life Quality ◽  
Atmospheric Plasma Spraying ◽  
Operating Conditions ◽  
Atmospheric Plasma ◽  
Hip Implants ◽  
Cobalt Chromium ◽  
Standard Material ◽  
Surgical Implants

For decades, the standard metallic materials for hip implants, besides the 316LVM stainless steel, were titanium- and cobalt/chromium-based alloys. Although bioinert, due to their corrosion resistance, they are not biocompatible. Contemporary surgical implants are not made just of bioinert metal anymore, but with deposited bioactive hydroxyapatite (HAp) coating. Hydroxyapatite is chemically identical with the mineral constituent of bones and teeth, what besides its biocompatibility provides bioactivity as well. The HAp limitations are, however, weak tensile strength and low fatigue resistance for long term loadings, if used alone. This is the reason for HAp to be deposited onto the surgical implant, and to enable its bioactivity, what means intergrowth with bones, and therefore the long-lasting and mechanical stable non-cemented prosthesis. This is important predominantly because the need for such prostheses for younger population, and a better life quality. There are several contemporary techniques that have been used for deposition of these coatings onto the metal implant. The possibilities of atmospheric plasma-spraying for obtaining the stable HAp coatings on the 316LVM stainless steel, ordinary used as a standard material for hip implants production are presented in this paper. The coatings of a commercially available hydroxyapatite powder were plasma-sprayed onto the specimens of medical grade 316LVM stainless steel under various operating conditions. The optical microscopy was used for microstructure and porosity characterization, while coating morphology and Ca/P ratio were analyzed using SEM equipped with EDX. Coating microstructure varied from a porous to a glassy structure, depending on operating conditions applied and coating thickness. Coating porosity was determined to be at the lower required limit requested for the bone-coating intergrowth possibility, but nevertheless adhesion measurements showed good results. The Ca/P ratio was determined for both as-deposited coatings and after ageing in distilled water for various time and temperature combination.

scholarly journals Thermal Stability of YSZ Thick Thermal Barrier Coatings Deposited by Suspension and Atmospheric Plasma Spraying

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 984
Author(s):  
Shiqian Tao ◽  
Jiasheng Yang ◽  
Minglong Zhai ◽  
Fang Shao ◽  
Xinghua Zhong ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Thermal Barrier Coatings ◽  
Thermal Aging ◽  
Thermal Exposure ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Aps Coatings ◽  
Steel Substrates

Two types of segmentation-crack structured yttria-stabilized zirconia (YSZ) thick thermal barrier coatings (>500 μm, TTBCs) were deposited onto the stainless steel substrates using atmospheric plasma spraying (APS) and suspension plasma spraying (SPS) process, respectively. In this work, thermal aging behaviors, such as the microstructures, phase compositions, grain growth, and mechanical properties of APS TTBCs and SPS TTBCs, were systematically investigated. Results showed that both as-sprayed TTBCs exhibited a typical segmentation-crack structure in the through-thickness direction. APS coatings mainly comprised of larger columnar crystals, while a large number of smaller equiaxed grains existed in SPS coatings. Both of the coatings underwent tetragonal-monoclinic phase transformation after 155 °C/40 h heat treatment. The poorer phase stability of SPS TTBCs may have a connection with smaller grain size. Thermal-aged APS and SPS coatings exhibited a significant increase in H and E values with the rising of thermal aging temperature, and for the samples that thermal aged at 1550 °C, the H and E values increased sharply during initial stage then decreased after 80 h due to the phase decomposition. The segmented APS coatings had weak bonding between the lamellaes during thermal exposure, which caused the mean Vickers hardness value of APS TTBCs to be much lower than that of SPS TTBCs.

Fabrication and electrical properties of 0.7BiFeO3-0.3PbTiO3 films on stainless steel by the sol-gel method

2012 ◽  
Vol 1449 ◽  
Author(s):  
Chen Zhao ◽  
Dan Jiang ◽  
Shundong Bu ◽  
Jinrong Cheng
Keyword(s):  
Stainless Steel ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Pt Films ◽  
Steel Substrates

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.

Measurement of Deformation-Induced Martensite in Stainless Steel Using Magnetic Contact Force

2012 ◽  
Vol 706-709 ◽  
pp. 2217-2221
Author(s):  
Tadashi Nishihara
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Stainless Steels ◽  
Volume Fraction ◽  
Austenitic Stainless Steels ◽  
Measuring System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Excellent Corrosion Resistance ◽  
Novel Method

Metastable austenitic stainless steels are attractive industrial materials with excellent corrosion resistance, mechanical properties, and formability. However, during plastic deformation, α’martensite can be formed. The volume fraction of that particular phase influences the mechanical and other properties (such as corrosion resistance) of these steels. Therefore, it is important to determine the amount of α’martensite in the obtained microstructures. Currently, the volume fraction of deformation-induced martensite in stainless steel is most commonly measured by the X-ray diffraction or magnetic permeability methods. In this study, a novel method of measuring deformation-induced martensite using magnetic contact holding force is proposed. Measurement trials were carried out using a prototype measuring system, and the results of measurements taken from SUS301 and SUS304 stainless steels are discussed in terms of deformation and martensite volume fraction.

scholarly journals Formation Mechanism of Al2O3-YAG Amorphous Ceramic Coating Deposited via Atmospheric Plasma Spraying

2021 ◽  
Author(s):  
Zheyi Zhang ◽  
Yizhaotong Ai ◽  
Xinghua Zhong ◽  
Yin Zhuang ◽  
Jing Sheng ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Formation Mechanism ◽  
Phase Distribution ◽  
Raw Materials ◽  
Thermal Spray Technology ◽  
Eutectic Point ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Amorphous Coating ◽  
Ultra Fast Cooling

Abstract This study mainly investigated the formation mechanism of Al2O3-YAG(Al5Y3O12) amorphous coating prepared by atmospheric plasma spraying. Nano and micro-sized powders with low eutectic point ratio were selected as raw materials for comparison. XRD, SEM and EBSD were used to analyze the phase composition, morphologies, phase distribution and structure of the coating. The crystal structures of the possible existed phases were studied to analyze the crystallization chemistry of powder droplets. It is concluded that the composition ratio of powders and particle size should be also considered as the key factors for the preparation of amorphous coatings besides the high enthalpy and ultra-fast cooling rate of thermal spray technology. The as-sprayable powder chose multiple components with low eutectic point ratio distributed uniformly at nano-scale or sub-micro scale, and can reacted to form the new phase crystal with high coordination numbers of cations.

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