Plasma-sprayed La2O3-modified HfC-SiC (HSL) coating was prepared on SiC-coated carbon/carbon composites to obtain an elevated ablation resistance under a heat flux of 2.38 MW/m2. The elastic modulus of sprayed HSL coating is about 140.97 GPa, 41.48 % greater than HfC-SiC (HS) coating. HSL coating also performed superior ablation resistance evidenced by integrated scale and stable ablation rates. Besides

Cyanate ester (CE) and graphene oxide (GO) were employed to modify epoxy-based coating (EP) by chemical reaction, and related corrosion protection behaviors were investigated in sulfuric acid solution. Epoxy coating modified by cyanate ester (CE/EP) displayed slower electrolyte diffusion. Further, incorporating 1 wt.% GO into CE/EP (1 wt.% GO/CE/EP) significantly enhanced the anti-corrosion properties

Coupon immersion tests were performed on 316 L stainless steel in a simulated oilfield environment to evaluate the effect of H2S partial pressure on pit depth and density. Pitting was most significant at intermediate partial pressures of H2S, for which free H2S in the pit solution is maximised. Inhibition of pitting at higher partial pressures is attributed to blocking of the pit surface by metal sulphide

TiSiN coatings with different silicon content were deposited on 316 L steel by cathodic arc ion plating. After exposure, TiSiN coated samples presented good LBE corrosion resistance as compared with the bare steel. The main changes in TiSiN coatings were the oxidation of Ti and TiN and the PbBi penetration. The penetration depth was highly dependent on the silicon content and the observed lowest depth

In this study, the oxidation behavior of AlCoCrFeNi high-entropy alloy powder at 900－1100 °C was first investigated and reported. The triple-phase nanostructure in the early oxidation stage is beneficial to the fast establishment of an exclusive Al2O3 scale. The AlCoCrFeNi powder exhibits the extremely low oxidation rate, the fairly high activation energy for oxidation and the relatively low residual

Effect of elastic stress on the rust layer of S450EW weathering steel formed in salt-spray was studied through electrochemical methods and characterisations on rust layers. Results show that stratification of the rust layer is mitigated with stress level enhanced on the steel. The stratification involves the magnetic Fe3O4/γ-Fe2O3 phase(s), which tends to segregate in the inner sublayer. The segregation

This work studies the corrosion behavior of β-Sn and intermetallic compounds (IMCs) in Sn96.5Ag3.0Cu0.5 (SAC305) alloy through micro-structure observation, in-situ electrochemical technique and first-principles calculation. The results show that corrosion behavior of SAC305 is affected by galvanic corrosion, electronic structure and material microstructure. The Volta potential difference between Cu6Sn5

A multi-degree of freedom mechanistic-chemometrics model for predicting the pitting damage of HP-13Cr stainless steel is developed by combining the mechanistic models and chemometrics method. The mechanistic model is reconstructed by considering the effect of single factors, such as high temperature, high CO2 pressure, flow rates and complex stress distribution. The single mechanistic models are combined

Fe-9Cr, Fe-9Cr-1Mo and Fe-9Cr-0.5Mo-0.5Ni (wt%) alloys have been prepared for studying the effect of (Mo, Mo/Ni) on carbide precipitation, oxidation behavior and high-temperature tensile property of Fe-9Cr alloy. Rod-shaped Cr23C6 precipitates in Fe-9Cr alloy were refined and spheroidized by Mo addition, while Mo/Ni addition had no impact on Cr23C6 precipitates. Adding (Mo, Mo/Ni) to Fe-9Cr alloy reduced

In this paper the corrosion behavior of high temperature corrosion resistant alloys is investigated in a gas atmosphere containing HCl and H2S at 480 °C and 680 °C. By considering the vapor pressures of the metal chlorides and the water gas shift reaction, as well as the influence of H2S, the different corrosion behavior at 480 °C compared to 680 °C can be explained and a model of the course of corrosion

Hydrogen blister (HB) and hydrogen-induced cracking (HIC) of pure iron at various charging times were investigated. The results show that an increase in charging time leads to the increased HB height/width and HIC length/depth, and a change in hydrogen damage morphology. Subsurface HIC initiates and propagates along the grain boundaries, which makes the surface bend outwards to form blister on blister

Rare earth elements have a great positive influence on the oxidation behavior and thereby on the lifetime of TBC systems. A commonly used EB-PVD NiCoCrAlY bondcoat was doped by Hf and Zr in a range of 0.1–1 at.%. More than 3000 cycles were achieved by Hf-doping in a range of 0.15−0.6 at.% Hf which is a large improvement. Zr doped BCs provide high lifetimes of about 2800 cycles with a low doping content

The corrosion, passive layer characteristics, and surface morphology of Ti-45Nb in fluoride-containing H2SO4 solutions are evaluated through electrochemical measurements and surface profilometry. Ti-45Nb spontaneously passivated in solutions with 0 and 0.0025 M F−, contrasting with the active-passive behaviour observed at 0.025 and 0.05 M F−. The corrosion resistance of Ti-45Nb decreases with increasing

(Attention for corrosion science, the abstract must not exceed more than 100 words) In this research, first a multi-analytical approach was carried out to propose a mechanistic model for the formation of the thermal oxide film on low Cr stainless steel. It describes the effects of kinetically and thermodynamically driven phenomena on the growth of a Fe-Cr complex oxide film at 950℃. Second, the behavior

This study focused on the objective to reveal the effect of Si element on the oxidation behaviors of (Ti5Si3 + TiC)/Ti6Al4V composites. The oxidation testing at 700 °C and 800 °C for 100 h, respectively, indicated that the oxidation resistance of (Ti5Si3 + TiC)/Ti6Al4V composites were improved obviously. The two aspects contributed to the improvement: 1) the oxide scale was densified owing to that

Electrochemically integrated multi-electrode arrays are variously designed for probing complex localised corrosion initiation and propagation processes occurring over different spatial and temporal scales. Electrode arrays made of 100 µm and 1 mm diameter aluminium alloy AA2024-T3 wires were used to illustrate the probing of submillimetre and millimetre scale localised corrosion processes over heterogeneous

The corrosion performance of several model and commercial Ni-base alloys, with 20 − 25 wt % Cr, in CO2-H2O gases at 750 °C with and without sulphate deposits was examined. In the absence of sulphate deposits, commercial NiCoCrAl alloy and Alloy 625 formed chromia-rich scales, but model alloys Ni-25Cr and Ni-25Cr-2Mn-1Si did not. Wagner’s theory was employed to interpret this different behaviour in

The precise manipulation of grain boundary microstructure, including interfacial solute partition and precipitate distribution, is crucial for regulating the corrosion resistance of age-hardening aluminum alloys. In this study, we explored a novel manipulation pathway, the pulsed electric field (PEC), to regulate solute segregation to grain boundary to form a specific grain boundary structure. The

The cyclic ablation behavior of C/C-ZrC-SiC-ZrB2 composites was investigated following 30s×4 and 60s×2 cycles at the heat fluxes of 2.38 and 4.18 MW/m2, respectively. At the two heat fluxes, the surface temperature of cyclic ablation of 30s×4 was lower than that of 60s×2. Microstructure characterization indicated that the center and transition region consisted of a layered structure of the outer ZrO2

Hydrogen embrittlement behavior of three austenitic stainless steels with 0.1−0.3 wt.%C was investigated. Carbon alleviated hydrogen-induced degradation of tensile properties. Increasing the carbon content over 0.1 wt.% hardly influenced hydrogen diffusivity. Hydrogen caused cracks to initiate at grain boundaries on the sample surface, and to propagate inside the grains through α’ and ε martensites

Knowledge gaps exist concerning the acoustic emission (AE) during the pitting corrosion of open morphology. Here, we proposed a simple yet effective strategy to control the pitting evolution uncovered by lacy covers or corrosion products in a vertically positioned 304 stainless steel (304 SS) specimen that was pretreated by immersion in dilute nitric acid. The corrosion pit developed with a “head”

In this study, corrosion behavior of Yb2O3-Y2O3 co-stabilized ZrO2 (YbYSZ) was systematically investigated under CMAS melt attack. The result was found that YbYSZ exhibited a better CMAS resistance than yttria stabilized zirconia (YSZ), which was attributed to the excellent phase stability. The degradation of grain caused by CMAS attack was greatly related to the diffusion rate of element substantially

Corrosion fatigue (CF) tests of Alloy 52/52 M weld metal from a safe-end welding joint of reactor pressure vessel were performed in B/Li high-temperature water. The CF cracks developed preferentially in 52 Mw with columnar grain orientation at a 45° - 75° angle to cyclic loading axis, rather than in 52b with columnar grain orientation parallel to loading axis. The environmental assisted fatigue effects

This paper reports an attempt to speculate about corrosion resistance of T91 steel to extreme lead–bismuth eutectic (LBE) flow pattern. We build a modified dynamic corrosion apparatus permitting assemblages of oxidation, erosion or dissolution attack proceeding together within oxygen-saturated LBE. After corrosion test at 400℃ up to 1000 h, discrepancies of corrosion performance under various flow

Tribocorrosion of Ti6Al4 V alloy has been investigated in 3.5 wt.% NaCl solution under simulated deep-sea environment. The results demonstrate tribocorrosion rate increases with hydrostatic pressure (i. e. seawater depth) at an accelerated speed of 5.9×10-6 mm3·N-1·m-1·MPa-1. Wear volume under potentiostatic tribocorrosion depends on potential and experiences a maximum at -0.2 VAg/AgCl where the volume

The high-temperature oxidation resistances of Ni-based superalloys with the compositions of Ni–(0–15)Co–(8–15)Cr–(0–5)Mo–(0–10)W–(3–8)Al–(0–5)Ti–(0–10)Ta–0.1C–0.01B were analyzed using an artificial neural network (ANN). The oxidation resistances of the alloys were evaluated based on the weight change measured during cyclic oxidation tests. An ANN was constructed with the contents of the alloying elements

The corrosion behavior and corrosion rate of friction stir welded AZ31B magnesium alloy and 6N01 aluminum alloy dissimilar joints were studied using real-time imaging, potentiodynamic polarization, EIS, and hydrogen evolution tests. The corrosion rate was found to increase, in order, Al base metal (BM-6N01) < Mg base metal (BM-AZ31B) < stirred zone. The galvanic coupling of the Mg phase to the other

The Al-Si-Fe-Mg-Cu-Zn alloy was used to manufacture large, thin-walled parts for 5 G base stations by using the ultrasonic vibration-assisted air-cooled stirring rod rheological die-casting (ACSR + UV R-DC) process. Investigations were performed on the microstructure and corrosion resistance of the ACSR + UV R-DC alloy which was then compared with traditionally die-casting (T-DC) and ACSR R-DC alloys

Microbiologically influenced corrosion inhibition (MICI) of aluminum alloy (AA) 5083 by three representative Vibrio species were evaluated using electrochemical, surface analysis and surface characterization techniques. Interestingly, all the bacteria exhibited profound inhibitory effect on the corrosion of AA5083 in the chloride-containing culture medium. The MICI mechanism of tested Vibrio species

The corrosion behavior of Zircaloy-4 (Zry-4) at 360 °C 0.01 M LiOH aqueous solution was in-situ monitored by electrochemical impedance spectroscopy (EIS). The EIS spectra of the as-received Zry-4 (Zry-4A) shows two-time constants feature during corrosion. The oxide layer impedance and capacitive show cyclic behavior while those of β-quenched Zry-4 sample (Zry-4Q) increased with exposure time increases

In the present work, a flash-PEO coating is developed on AZ31B alloy in a combination of silicate, phosphate, and fluoride based electrolyte in order to offer a green alternative to chromate conversion coatings. Multilevel active protection is achieved through synergetic combination of self-sealing effect of PEO coating itself and active inhibition provided by an organic inhibitor impregnated in PEO

Previous research has inadequately elucidated the influence of Nb addition on the tensile properties and oxidation resistance of Ti-based alloys. Herein, the tensile properties and oxidation resistance of Ti–6Al–2Sn–4Zr–2Mo–0.1Si–1.0B–xNb (x = 0, 0.2, and 1.0) alloys were investigated. The oxidation resistance was significantly improved by Nb addition without significantly influencing the tensile properties

Comparative investigation on the oxidation behavior at 1000 °C of a nanocrystalline duplex coating, which comprised outer Ni + CrAlYNO cermet and inner NiCrAlY layers, a monolayer NiCrAlY coating and a monolayer cermet coating was carried out. The oxidation rates of the duplex coating are the lowest, because non-alumina oxides were detected on both monolayer coatings though α-Al2O3 was formed on all

In this study, the oxidation behavior of AlCoCrFeNi2.1 eutectic high entropy alloy (EHEA) with/without Y doping at 1000 °C and 1100 °C was reported. The doping of minor Y is crucial to improving the Al2O3 scale adhesion and achieving its durability at high temperatures. The oxidation rates of Y-doped AlCoCrFeNi2.1 EHEA at 1000 °C and 1100 °C are comparable and even lower compared with conventional

The oxidation behaviors of Ti3AlC2 and Ti3Al0.8Sn0.2C2 powders in air over the temperature range from 450 to 900 ℃ have been comprehensively compared. First-principles calculations suggest that Sn doping can decrease the oxidation resistance of Ti3AlC2 powders due to its weakening effect on the Ti-Al bonds. There are three stages of both powders depending on the oxidation temperature, in which the

A CO2-responsive coating has been developed by adding a thiourea-containing nanocontainer with pH-response release property into an ethyl cellulose coating. The cumulative release of thiourea in the nanocontainer changes with the pH of aqueous solution, which enabled the release rate of thiourea from the nanocontainer in coating to adapt to the change in corrosiveness of 3.5 wt. % NaCl with different

The 7xxx series of aluminium alloys are sensitive to intergranular hydrogen environmentally assisted cracking (HEAC) in moist air environments. A new generation of 7xxx alloys used in aircraft components (including AA7449) have been found to be more sensitive to HEAC. This investigation aims to quantify the HEAC crack growth rates of AA7449-T7651 in moist air at different temperatures. Double cantilever