Corrosion and Oxidation Protection of Ti6Al4V Alloy by an Inorganic Metal Modified Silicate Composite Coating

2010 ◽  
Vol 654-656 ◽  
pp. 1952-1955 ◽  
Author(s):  
Cheng Wang ◽  
Sheng Long Zhu ◽  
Fu Hui Wang
Keyword(s):  
Thermal Shock ◽  
Composite Coating ◽  
Salt Spray ◽  
Mass Gain ◽  
Isothermal Oxidation ◽  
Ti6al4v Alloy ◽  
Coated Alloy ◽  
Oxidation Properties ◽  
Oxidation And Corrosion ◽  
Corrosion And Oxidation

An inorganic metal modified silicate composite coating was developed to protect the corrosion and oxidation of Ti6Al4V alloy at 650°C. The properties of the coatings were investigated by oxidation and corrosion experiments, and the microstructure of the coatings was studied by SEM. The isothermal oxidation results indicated that the Ti6Al4V alloy suffered serious oxidation after exposed for 100h at 650°C and the mass of the alloy gained almost lineally, while the coated alloy had almost no mass gain and the coatings keep intact after oxidation. The salt spray test for 20h and oxidation at 650°C for 2h was carried out to investigate the corrosion and oxidation properties of the coatings. The results indicated that the alloy experienced serious corrosion after experiment for 20 cycles, while the coated alloy did not corrode after the experiments. The thermal shock experiments indicated that the coatings could withstand 50 times thermal shock when kept for 5min at 700°C and then immediately put into 3.5%NaCl solution at room temperature.

scholarly journals Isothermal Oxidation Performance of Laser Cladding Assisted with Preheat (LCAP) Tribaloy T-800 Composite Coatings Deposited on EN8

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 843
Author(s):  
Sipiwe Trinity Nyadongo ◽  
Sisa Lesley Pityana ◽  
Eyitayo Olatunde Olakanmi
Keyword(s):  
Iron Oxide ◽  
Composite Coating ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Parabolic Rate Constant ◽  
Mass Gain ◽  
Isothermal Oxidation ◽  
Operational Parameters ◽  
Temperature Oxidation ◽  
Service Environments

It is anticipated that laser cladding assisted with preheat (LCAP)-deposited Tribaloy (T-800) composite coatings enhances resistance to structural degradation upon exposure to elevated-temperature oxidation service environments. The oxidation kinetics of LCAP T-800 composite coatings deposited on EN8 substrate and its mechanisms have not been explored in severe conditions that are similar to operational parameters. The isothermal oxidation behaviour of the T-800 composite coating deposited on EN8 via LCAP was studied at 800 °C in air for up to 120 h (5 × 24 h cycles) and contrasted to that of uncoated samples. The mass gain per unit area of the coating was eight times less than that of the uncoated EN8 substrate. The parabolic rate constant (Kp) for EN8 was 6.72 × 10−12 g2·cm−4·s−1, whilst that for the T-800 composite coating was 8.1 × 10−13 g2·cm−4·s−1. This was attributed to a stable chromium oxide (Cr2O3) layer that formed on the coating surface, thereby preventing further oxidation, whilst the iron oxide film that formed on the EN8 substrate allowed the permeation of the oxygen ions into the oxide. The iron oxide (Fe2O3) film that developed on EN8 spalled, as evidenced by the cracking of oxide when the oxidation time was greater than 72 h, whilst the Cr2O3 film maintained its integrity up to 120 h. A parabolic law was observed by the T-800 composite coating, whilst a paralinear law was reported for EN8 at 800 °C up to 120 h. This coating can be used in turbine parts where temperatures are <800 °C.

Determination of structural, tribological, isothermal oxidation and corrosion properties of Al–Co–Cr–Fe–Ni–Ti–Cu high-entropy alloy

Vacuum ◽  
2021 ◽  
Vol 187 ◽  
pp. 110072
Author(s):  
Sefa Emre Sünbül ◽  
Kürşat İçi̇n ◽  
Fatma Zehra Şeren ◽  
Ömer Şahin ◽  
Damla Dilara Çakil ◽  
...  
Keyword(s):  
Isothermal Oxidation ◽  
High Entropy Alloy ◽  
Corrosion Properties ◽  
High Entropy ◽  
Oxidation And Corrosion

In situ Raman spectroscopy study on the effect of antioxidants on high temperature oxidation properties of TMPTO

2019 ◽  
Vol 71 (5) ◽  
pp. 706-711 ◽  
Author(s):  
Bingxue Cheng ◽  
Haitao Duan ◽  
Yongliang Jin ◽  
Lei Wei ◽  
Jia Dan ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Temperature ◽  
Thermal Oxidation ◽  
High Temperature Oxidation ◽  
Isothermal Oxidation ◽  
In Situ Raman Spectroscopy ◽  
Temperature Oxidation ◽  
Content Type ◽  
Structure Changes ◽  
Oxidation Properties

Purpose This paper aims to investigate the thermal oxidation characteristics of the unsaturated bonds (C=C) of trimethylolpropane trioleate (TMPTO) and to reveal the high temperature oxidation decay mechanism of unsaturated esters and the nature of the anti-oxidation properties of the additives. Design/methodology/approach Using a DXR laser microscopic Raman spectrometer and Linkam FTIR600 temperature control platform, the isothermal oxidation experiments of TMPTO with or without 1.0 wt. % of different antioxidants were performed. Findings The results indicated that the Raman peaks of =C-H, C=C and -CH2- weaken gradually with prolonged oxidation time, and the corresponding Raman intensities drop rapidly at higher temperatures. The aromatic amine antioxidant can decrease the attenuation of peak intensity, as it significantly reduces the rate constant of C=C thermal oxidation. The hindered phenolic antioxidant has a protective effect during the early stages of oxidation (induction period), but it may accelerate the oxidation of C=C afterwards. Originality/value Research on the structure changes of synthetic esters during oxidation by Raman spectroscopy will be of great importance in promoting the use of Raman spectroscopy to analyze the oxidation of lubricants.

Corrosion resistance of composite coating used for fastener protection

2019 ◽  
Vol 66 (5) ◽  
pp. 595-602
Author(s):  
Zhifeng Lin ◽  
Likun Xu ◽  
Xiangbo Li ◽  
Li Wang ◽  
Weimin Guo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Composite Coating ◽  
Marine Environment ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Diffusion Method ◽  
Economic Losses ◽  
Neutral Salt ◽  
Content Type

Purpose The purpose of this paper is to examine the performance of a fastener composite coating system, sherardized (SD) coating/zinc-aluminum (ZA) coating whether it has good performance in marine environment. Design/methodology/approach In this paper, SD coating was fabricated on fastener surface by solid-diffusion method. ZA coating was fabricated by thermal sintering method. Corrosion behaviours of the composite coating were investigated with potentiodynamic polarization curves, open circuit potential and electrochemical impedance spectroscopy methods. Findings Neutral salt spray (NSS) and deep sea exposure tests revealed that the composite coating had excellent corrosion resistance. Polarization curve tests showed that corrosion current density of the sample with composite coating was significantly decreased, indicating an effective corrosion protection of the composite coating. OCP measurement of the sample in NaCl solution demonstrated that the composite coating had the best cathodic protection effect. The good corrosion resistance of the composite coating was obtained by the synergy of SD and ZA coating. Practical implications SD/ZA coating can be used in marine environment to prolong the life of carbon steel fastener. Social implications SD/ZA composite coating can reduce the risk and accident caused by failed fastener, avoid huge economic losses. Originality/value A new kind of composite coating was explored to protect the carbon steel fastener in marine environment. And the composite coating has the long-term anti-corrosion performance both in simulated and marine environment test.

Microstructure evolution and isothermal oxidation properties of c-AlPO4 and SiC whisker co-modified mullite coated SiC-C/SiC composites

2019 ◽  
Vol 45 (16) ◽  
pp. 20704-20713 ◽  
Author(s):  
Dongmei Pu ◽  
Pengju Chen ◽  
Peng Xiao ◽  
Zhuan Li ◽  
Zeyan Liu ◽  
...  
Keyword(s):  
Microstructure Evolution ◽  
Isothermal Oxidation ◽  
Oxidation Properties ◽  
Sic Composites

Study on Thermal-Shock-Resistance of the Composite Coating of 20 Steel Substrate by Hot Dip Aluminum and Micro-Arc Oxidation

2016 ◽  
Vol 723 ◽  
pp. 450-453
Author(s):  
Xiao Feng Sun ◽  
Yuan Lin Huang ◽  
Wei Song ◽  
Ming Ming Sun
Keyword(s):  
Residual Stress ◽  
Thermal Shock ◽  
Composite Coating ◽  
Thermal Shock Resistance ◽  
Steel Substrate ◽  
Steel Plates ◽  
Micro Hardness ◽  
Combined Process ◽  
Micro Arc Oxidation ◽  
Shock Resistance

By combined process of hot dip aluminum and micro–arc oxidation, a multilayer composite coating was obtained on the surface of 20 steel plates. The micro-hardness, morphology, residual stress and thermal-shocking performance of the coating were investigated by HVS-1000 micro-hardness instrument, SEM, X-350 stress instrument and etc. The results showed that the micro-hardness of the coating appeared hard-soft-hard from surface to inner, the effective thermal-shock times of the coating was 130, its residual stress of the coating was 181.7 MPa after hot shock 80 times.

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