The grain size and Mg2Ca morphologies of Mg–1Sn–1Ca-0.3Mn (TX11) alloy are tailored using different cooling methods (furnace cooled, air cooled, oil cooled and water cooled). Optical microscopy (OM) ...and scanning electron microscopy (SEM) are used to observe the microstructure, and the electrochemistry workstation and Mg-air battery tests are used to investigate the electrochemical corrosion behaviors and Mg-air battery anodic performance. The results reveal that cooling methods lead to refine grain and the Mg2Ca-phase morphology changed from linear-like shape to needle-like shape. The linear-Mg2Ca phase induced by furnace cooled is beneficial for improving electrochemical activity and discharge voltage during the discharge process. Among all TX11 alloy, the average discharge voltage of furnace-cooled TX11 alloy reaches 1.163V at a current density of 20 mA cm−2. In addition, the small grain and uniform distribution round-shape Mg2Ca phase prepared via oil cooled leads to the alloy best corrosion resistance and best comprehensive discharge performance, with the average discharge voltage, anodic efficiency, specific capacity and specific energy of 1.152V, 57.8%, 1290.3 mA h g−1 and 1487.5 mW h g−1 at 20 mA cm−2 among four alloys, respectively. The cooling methods provide a new idea for improving the comprehensive discharge performance of Mg-air battery anodes.
•TX11 alloy are tailored using different cooling methods in the first time.•Effect of grain size and Mg2Ca morphology on anode performance is investigated.•OC-TX11 Mg-air battery anode exhibits good comprehensive discharge performance.•Cooling methods provide a new idea for improving Mg-air battery anode performance.
Improving corrosion resistance is a challenging task, as it determines the life time of thermal barrier coatings (TBCs). In this regard, this study was aimed to characterize the electrochemical ...corrosion behaviour of nanostructured Gadolinium Zirconate in three different corrosive salt conditions such as Na2SO4 + 55 wt% V2O5 (SM1), Na2SO4 + 10 wt% NaCl (SM2), and Na2SO4 + 7.5 wt% NaCl +7.5 wt% V2O5 (SM3). The uniformity of the coated surface was verified by mapping the vibrational bands associated with Gd and Zr using FT-IR and Raman spectroscopy. The coated surface possessed a uniform columnar structure with leafy appearance. Potentiodynamic polarisation studies and electrochemical impedance spectroscopic data demonstrated that the nanostructured GZ exhibited superior corrosion resistance properties under SM1 salt condition as compared to SM2 and SM3 conditions. SEM and EDS analysis were used to evaluate the nanostructured GZ coatings that were subjected to electrochemical corrosion. In the case of SM2 and SM3 conditions, the surfaces were degraded with microcracks. The formation of corrosion products and the exposure of succeeding layers as a result of corrosion were also characterized using FT-IR, Raman spectroscopy, XRD technique and 3D optical microscope.
•Nanostructured GZ TBCs deposited by EB-PVD exhibited a columnar microstructure with leafy morphology without pits and pores.•Raman mapping and FT-IR mapping of vibrational bands due to Gd and Zr confirms the uniformity of the coatings.•Electrochemical corrosion studies show superior corrosion resistance characteristics of nanostructured GZ under SM1 corrosive salt condition.
Nickel–graphene (N–G) composites are potential candidate structural materials for molten salt reactors. A rapid preparation method for these composites by jet electrodeposition was developed, and the ...microstructure, microhardness, and corrosion properties of these composites were studied to explore the key parameters of the jet electrodeposition. Results indicated that the distribution of graphene in composites mainly depended on the concentration of graphene oxide (GO) in the plating solution. Composites deposited with GO concentration of 0, 0.5, 1 g/L showed surface root-mean-square roughness value (Rq) of 6, 12, and 28 nm, respectively. Meanwhile with the increase of GO concentration, the Hardness value became larger. The corrosion potential Ecorr and current Icorr of composites obtained at 0.5 g/L with the best surface quality were 193 mV and 5.7 × 10−6 A/cm2, respectively, which indicated the best electrochemical corrosion resistance. Hydrogen annealing can help self–repair of graphene microstructure.
•Metal graphene composites were successfully prepared by jet electrodeposition.•This method increases the limiting current density and the composites quality.•Studied the effects of different GO concentration on the composite properties•Optimized GO concentration can improve the composites' comprehensive property.
Thermal sprayed HVOF WC-based cermet coatings containing various metallic binders have been used in several different applications in industries that require abrasive sliding wear resistance, such as ...hydraulic pistons, shafts or bearings. The potential dangerousness and cost increase off cobalt-based metallic binders, underlining the challenge in reducing reliance on this metal as metallic binder in wear resistant coatings. The present work aims to study the feasibility of WC-NiMoCrFeCo, WC-CrC-Ni and WC-FeCrAl coatings, in contrast to conventional WC-CoCr, by evaluating their microstructure, mechanical, tribological and corrosion resistance properties. Commercially feedstock powders were sprayed onto steel plates using a kerosene-fuelled HVOF WokaJet 400 gun. The WC-CoCr coating shows a slightly highest hardness than WC-NiMoCrFeCo and WC-FeCrAl coatings, showing a slight trend towards an increase in the wear rate as the coating hardness decreases. The WC-CrC-Ni coating is significantly the softest and least wear resistant coating, as a consequence of the presence of a high percentage of lower hardness CrC particles. Nevertheless, this coating shows similar corrosion resistance to of conventional WC-CoCr coating, while the WC-NiMoCrFeCo and WC-FeCrAl coatings show a slightly worse corrosion resistance.
•Three cermet HVOF coatings with different cobalt free metallic binders are evaluated as alternative to the WC-CoCr coating.•The binder composition of coatings does not greatly influence the wear mechanism under sliding wear tests.•The corrosion of the coatings depends on the chromium content that favors the formation of a surface protective layer.•The evaluated HVOF coatings can be an alternative to the WC-CoCr coating, both in terms of wear and corrosion resistance.
Corrosion by seawater is an electrochemical Corrosion, and all types of metals or alloys when they are in contact with seawater have a specific corrosion potential at a certain level of seawater ...alkalinity or acidity. Metal corrosion is a major technical problem and plenty of methods have been developed to provide solution. Inhibitor-enhanced coating can be recognized as the most efficient method. In this research, Halloysite nanotube (HNT) was used to create HNT-epoxy composite as protection towards corrosion without the inhibitor. The electrochemical impedance spectroscopy (EIS) study was done on HNT-epoxy composite coatings for corrosion protection carbon steel in 3.5% NaCl solution. The morphology analysis of the HNT was done by optical microscope and field emission scanning electron microscope(FESEM). The EIS characterizations showed a turning point of the composite coating from good to poor corrosion resistance performance. According to EIS measurements, increasing the halloysite concentration had resulted in the enhancement of the barrier effect and an increase in the ability to protect corrosion coating in NaCl solution. The corrosion morphology observations indicated that an increase in nanoparticle loading lead to an increase in the intercalation site and make the composite opaquer. Furthermore, the nanoparticles loading showed poor interaction with the epoxy composite, due to clustering of the nanoparticles and visible as wavy opaque surface. The findings show that the HNT is a very good alternative as a corrosion barrier in coating due to their viability and compatibility with diversity of water- and oil- based coatings onto a protected surface.
Zinc anodes in aqueous batteries always suffer from severe electrochemical corrosion and terrible dendrite growth. These issues could be alleviated by using hydrophobic polymers and ion-conductive ...inorganics together as an artificial layer. However, inorganics without special modifications always show an inferior compatibility with hydrophobic polymers, thus leading to a loose and porous layer and a limited inhibition of side reactions. Here, monodisperse hexagonal nanoplates of
α
-ZrP are intercalated by
n
-butylamine, successfully improving the compatibility with
N
-methyl pyrrolidone and poly(vinyldene fluoride) usually used as a recipe for artificial layers. The obtained layer on Zn is dense and robust, thus reducing the direct exposure of Zn to electrolytes and well suppressing the side reactions. This intercalation also increases the interlayer spacing and improves the charge transfer, enriching the future selection of conductive inorganics. Hence, the electrochemical performances are much better than those of bare Zn and untreated
α
-ZrP. Finally, a similar enhancement is confirmed in other layered structures, demonstrating the promising prospects of this strategy.
The intercalation of
n
-butylamine into layer-structured
α
-ZrP benefits the formation of a dense layer, reduces the transfer barrier of Zn
2+
and increases the local concentration of Zn
2+
, leading to enhanced electrochemical performances for Zn anodes.
•A new anti-corrosive non-equiatomic FeNiCoCr high-entropy alloy (HEA) is developed.•Mechanical and anti-corrosion properties of the HEA are systematically investigated.•The new HEA has higher ...corrosion resistance than equiatomic FeMnNiCoCr and 316L SS.•The passive films contain bound water and a high content of anti-corrosive Cr3+.•Complex oxide Co(Fe,Cr)2O4 in the passive film may promote the corrosion resistance.
The mechanical behavior and corrosion resistance of a newly developed non-equiatomic Fe40Ni20Co20Cr20 (at.%) high-entropy alloy (HEA) were investigated. Excellent strength-ductility synergy with fracture elongation of more than 70 % was found to be mediated by dislocation activities and nano-twinning. The alloy shows significantly improved corrosion resistance compared to the equiatomic FeMnNiCoCr HEA upon immersion testing, and higher electrochemical corrosion resistance than the 316L stainless steel in 0.1 M H2SO4 solution. Apart from a high content of Cr3+ in the passive film, the interaction between Co and other elements potentially leads to the formation of Co(Fe,Cr)2O4 and enhances the passive film stability.
•The surfaces of untreated and coated samples are hydrophilic.•The film surface with maximum corrosion resistance for all three of the SBF, DMEM and PBS solutions is Ag doped TiN.•SBF and DMEM showed ...similar performances in short-term experiments, which could be alternatives to each other.•TiN-based films significantly reduce the biodegradation rate of untreated AZ31, both electrochemically and using the immersion corrosion technique.
The biocorrosion phenomenon is an important mechanism that determines the biodegradability capacity. The effectiveness of studies on biodegradable materials is directly proportional to detailed corrosion experiments and analysis of formation mechanisms. In this context, experiments and analyzes have also become frequently used for magnesium alloys. In this study, TiN-based coatings were applied by physical vapor deposition method to tailor AZ31 alloy suitable for use as temporary implant material. Different in vitro media were used for comprehensive simulation of the biological environment, and material losses were interpreted on the basis of corrosive damage.
TiC reinforced CoCrFeNiMo high–entropy alloy coatings were fabricated on Ti6Al4V alloy by laser cladding, and the effects of TiC mass fraction on the microstructure, corrosive–wear and ...electrochemical properties were investigated. The results show that the laser cladded CoCrFeNiMo–TiC coatings consist of TiC, FeTi, Fe3Mo and Fe3C phases, and the hardness and forming quality were improved by the addition of TiC. The wear rates of CoCrFeNiMo–TiC coatings are decreased with the increase of TiC mass fraction, and the CoCrFeNiMo–20%TiC coating presents the highest corrosive–wear resistance. The corrosive–wear mechanism is primary abrasive wear, accompanied with adhesive wear, oxidative wear and pitting corrosion. Moreover, the CoCrFeNiMo–20%TiC coating has the best corrosion resistance, which is attributed to the addition of TiC.
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