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A comparative study of impact glasses from the Lonar crater, located on the Deccan basalt plateau, India, and impact glasses from lunar regolith delivered by the Soviet automatic stations (AS) Luna-16 and Luna-24 (Sea of Plenty and Sea of Crises) was carried out. Numerous natural alloys (Cu3Ni2, Ni2Cu and Ni3Cu) that were previously unknown in nature were discovered in the impactites of the Lonar crater and the regolith of the Moon. The discovery of such alloys expands the area of isomorphism in the Cu–Ni system. As a result of a comparison of impactites of the Earth and the Moon, similarities were discovered in the composition, size and morphology of particles of copper–nickel alloys, which may be an indicator of impact processes. One of the possible mechanisms for the formation of Ni–Cu particles was condensation from a gas–plasma cloud. A possible source of material for Cu–Ni alloys was both the impactor material and the target material. [ABSTRACT FROM AUTHOR]

Titanium alloys have broad application prospects in the field of marine engineering due to their excellent corrosion resistance and comprehensive mechanical properties. Titanium alloys, when connected with other metals, such as copper-nickel alloys, could produce two distinct effects. On the one hand, the passive film gives titanium alloys positive potential, which could accelerate galvanic corrosion of negative-potential metals. On the other hand, the passive film could obstruct current flow and prevent further development of galvanic corrosion. In this paper, Potentiodynamic Polarization, Electrochemical Impedance Spectroscopy, and Electrochemical Noise techniques were utilized to investigate the galvanic corrosion behavior of B10/Ti80 under simulated seawater environment. The corrosion morphology and product composition were studied using Scanning Electron Microscope and X-ray Photoelectron Spectroscopy. The above experimental results showed that Ti80 and B10 served as the anode and cathode respectively in the early stages of corrosion (within 2.5 h of immersion), due to the incomplete formation of the passivation film on Ti80. While in the latter stages of corrosion, due to the positive shift of Ti80's potential by passivation, there was a noticeable accelerated corrosion effect on B10, which was proportional to the area ratio of Ti80/B10 and showed a gradually stable trend after 28 days of immersion in the seawater. [ABSTRACT FROM AUTHOR]

For the first time, we investigated the process of potentiostatic anodic treatment of the surface of a copper (≈55%)-nickel alloy in a eutectic mixture of urea and choline chloride (reline), which is a typical representative of a new generation of ionic liquids, deep eutectic solvents. The anodic behavior of the alloy in the used solvent was characterized by cyclic voltammetry, and the nature of the electrochemical dissolution reactions of individual components of the alloy corresponding to several anodic current waves registered in voltammograms was determined. It was established that the anodic dissolution of the alloy occurs under conditions of salt surface passivation due to the formation of a layer of poorly soluble products of the electrode reaction. It was shown that under conditions of prolonged (150 min) potentiostatic polarization of the alloy in reline for various values of the electrode potential (in the range from 0.1 to 1.7 V relative to the Ag reference electrode), the chemical composition of the surface remained unchanged (i.e., there was no selective etching of individual components of the alloy), but an evolution of surface morphology patterns was observed, the specific type of which depended on the value of the applied potential. Anodic treatment of the Cu-Ni alloy in the reline solvent at any of the investigated anodic potentials led to an increase in the surface roughness coefficient, and electrochemical polishing did not occur. Analysis of kinetic data related to the hydrogen evolution reaction on the surfaces of reline-treated copper-nickel alloys in a 1 M NaOH aqueous solution showed a significant increase in exchange current density. This indicates enhancement of electrocatalytic activity compared to the untreated surface. The observed effect is likely associated with an increase in the true surface area of the alloy available for electrochemical reaction and an increase in the surface concentration of electrocatalytic sites resulting from the anodic dissolution of the alloy. The obtained results can be used in the development of highly efficient and relatively inexpensive electrocatalysts for hydrogen energy. [ABSTRACT FROM AUTHOR]

"The keyhole repair welding experiments were conducted on 5 mm thick BFel0-l-l copper-nickel alloy using the friction plug repar welding method. The study examined the micr-morphology, micr-hardness, temperature field distribution and mechanical properties of the plug repair welding joint at different spindle speeds. The results indicated that the spindle speed significantly influenced the plug welding form of the Copper-Nicke-Iron alloy. As the spindle speed increased, the weak connection defect at the bottom of the joint gradually diminished, the metal friction flow line in the plug area became more evident, and the gran was broken and reined. The heat affected zone was considerably reduced from the top to the bottom of the rewelded joint. Due to the fine gran s treng t hening, t he microhardness of t he plug zone was higher t han t ha t of t he base ma t eral, and t he microhardness of the upper side of t he plug zone was higher than that of the middle and lower side. The t ensile s trength of the joint was the highes t at 2 100 r/min, reaching 78% of t he base mat era. The joints showed duc tile fracture characteristics.With the increase of rotational speed, the weak connection defects of the joints gradually decreased and shrank. [ABSTRACT FROM AUTHOR]

Copper-based materials have long been used for their outstanding thermal and electrical conductivities in various applications, such as heat exchangers, induction heat coils, cooling channels, radiators, and electronic connectors. The development of advanced copper alloys has broadened their utilization to include structural applications in harsh service conditions found in industries like oil and gas, marine, power plants, and water treatment, where good corrosion resistance and a combination of high strength, wear, and fatigue tolerance are critical. These advanced multi-component structures often have complex designs and intricate geometries, requiring extensive metallurgical processing routes and the joining of the individual components into a final structure. Additive manufacturing (AM) has revolutionized the way complex structures are designed and manufactured. It has reduced the processing steps, assemblies, and tooling while also eliminating the need for joining processes. However, the high thermal conductivity of copper and its high reflectivity to near-infrared radiation present challenges in the production of copper alloys using fusion-based AM processes, especially with Yb-fiber laser-based techniques. To overcome these difficulties, various solutions have been proposed, such as the use of high-power, low-wavelength laser sources, preheating the build chamber, employing low thermal conductivity building platforms, and adding alloying elements or composite particles to the feedstock material. This article systematically reviews different aspects of AM processing of common industrial copper alloys and composites, including copper-chrome, copper-nickel, tin-bronze, nickel-aluminum bronze, copper-carbon composites, copper-ceramic composites, and copper-metal composites. It focuses on the state-of-the-art AM techniques employed for processing different copper-based materials and the associated technological and metallurgical challenges, optimized processing variables, the impact of post-printing heat treatments, the resulting microstructural features, physical properties, mechanical performance, and corrosion response of the AM-fabricated parts. Where applicable, a comprehensive comparison of the results with those of their conventionally fabricated counterparts is provided. [ABSTRACT FROM AUTHOR]

The growing market of printed electronics requires the development of new materials and processing technologies that enable the design of smart wearables, integrated sensors, and next-generation electronics. Against the backdrop of increasing material scarcity, these approaches must be resource-conserving and, at the same time, competitive with conventional technologies. As an alternative to nanoparticle-based inks currently used in printed electronics, another technology has been emerging in the last years that utilizes metal organic decomposition (MOD) inks, which are easy to fabricate and have a long shelf life. In this study, a method is presented that allows the direct formation of thin copper-nickel alloy films from a MOD ink. These alloys are preferably used for sensors like strain gauges as they exhibit a low thermal coefficient of resistivity (TCR). 250 nm thin alloy films are coated on glass substrates and thermally functionalized. In a conventional hot plate heat treatment under a nitrogen atmosphere, 10.2% bulk conductivity for a Cu55Ni45 alloy with a TCR of 8.3 × 10−5 K−1 is reached. X-ray diffraction analysis indicates the formation of a mixed crystal composed of nickel and copper atoms. A laser-based functionalization process is developed that allows the processing of Cu55Ni45 alloy films under ambient conditions without the formation of copper or nickel oxides. Laser-functionalized films exhibit 5.3% of the conductivity of bulk material. This study shows that metal alloy films can be fabricated directly from amine-based MOD inks. [ABSTRACT FROM AUTHOR]

The diffusion processes during the contact melting at the boundary of explosively welded VT1-0 titanium with CuNi19 (melchior) and CuNi45 (constantan) alloy composites were studied. Heat treatment of composites led to the formation of the interaction zone at the joint boundary. The interaction zone in VT1-0 + CuNi19 consists of TiCuNi and αTi + Ti2Cu(Ni) continuous layers as well as a mixture of TiNi(Cu) + TiCu(Ni) + Ti2Cu(Ni) intermetallics. It has been shown that an increase in the nickel content in the case of VT1-0 + CuNi45 composite leads to a decrease in the temperature of contact melting, a change in its mechanism, an increase in the titanium content in the interaction zone, and the appearance of additional Ti2Ni(Cu) intermetallic in its composition. [ABSTRACT FROM AUTHOR]

The 70/30 copper–nickel alloy is used mainly in critical parts with more demanding conditions in marine settings. There is a need for innovative methods that offer fast production and cost-effectiveness in order to supplement current copper–nickel alloy manufacturing processes. In this study, we employ wire arc additive manufacturing (WAAM) to fabricate the 70/30 copper–nickel alloy. The as-built microstructure is characterized by columnar grains with prominent dendrites and chemical segregation in the inter-dendritic area. The aspect ratio of the columnar grain increases with increasing travel speed (TS) at the same wire feed speed (WFS). This is in contrast with the equiaxed grain structure, with a more random orientation, of the conventional sample. The sample built with a WFS of 8 m/min, TS of 1000 mm/min, and a track distance of 3.85 mm exhibits superior corrosion properties in the 3.5 wt% NaCl solution when compared with the conventional sample, as evidenced by a higher film resistance and breakdown potential, along with a lower passive current density of the WAAM sample. The corrosion morphology reveals the critical roles played by the nickel element that is unevenly distributed between the dendrite core and inter-dendritic area. [ABSTRACT FROM AUTHOR]

The corrosion behavior of B30 copper‐nickel alloy in a deep‐sea environment was investigated by using the self‐built loop apparatus based on the response surface methodology. The results indicated that all the environmental factors accelerate the corrosion of alloys. The degree of effect of the individual factors decreased in the following order—dissolved oxygen > temperature > flow rate > pressure. Moreover, there exist interaction effects between any two of the environmental factors, of which the one between temperature and pressure is the most significant. A mathematical relationship between these factors and the corrosion behavior for B30 alloy was established. The accuracy of the corrosion model was verified by immersion and electrochemical testing. [ABSTRACT FROM AUTHOR]

Nickel (Ni)-rich single-phase nickel-copper (Ni-Cu) alloy coatings were produced on aluminum (Al) substrates by electrodeposition in stabilized citrate baths. Electrodeposition experiments were performed at four different current densities. Increasing the current density resulted in the metal deposition rate increasing faster than the hydrogen evolution rate; thus, the cathodic current efficiency increased. The crystal systems of the Ni-Cu alloys were face center cubic (fcc), with the (111) plane as the preferred crystal plane. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) measurements showed that the Ni content in the coating increased with increasing current density. The Ni-Cu 40 sample had the most Ni content and showed a homogeneous and compact morphology. It was found that the higher the concentration of Ni in the solution, the smaller the grain size. Measurements recorded with a vibrating sample magnetometer (VSM) showed that the Ni-Cu 40 sample provided magnetic saturation, with the highest value being 0.108 emu/g. The microhardness method produced 404 HV on the Ni-Cu 40 sample. In conclusion, higher current densities were associated with a higher Ni composition and increased thickness, which were responsible for the increases in the magnetic properties and hardness. [ABSTRACT FROM AUTHOR]

In the case of copper and its alloys, Wire Arc Additive Manufacturing (WAAM) 3D printing technology is mainly used to produce elements for the maritime industry and research has focused on the use of Cu-Al alloys. There is little information devoted to the use of Cu-Ni alloys in this technology, which are also widely used in the maritime industry. In this work, tests were carried out on the microstructure, mechanical properties, and corrosion properties in a 1M NaCl solution of Cu-Ni 90/10 alloy 3D walls printed using the WAAM method. The obtained objects are characterized by a microstructure with elongated column grains and particles of the Ni-Ti phase, hardness in the range of 138–160 HV10, ultimate tensile strength of 495–520 MPa, yield strength of 342–358 MPa, elongation of 16.6–17.9%, and a low average corrosion rate of 7.4 × 10−5 mm/year. The work shows that it is possible to obtain higher mechanical properties of Cu-Ni 90/10 alloy 3D objects produced using the WAAM method compared to cast materials, which opens up the possibility of using this alloy to produce objects with more complex shapes and for use in corrosive working conditions. [ABSTRACT FROM AUTHOR]

The article presents the results of studying the elemental and isotopic composition of alloy films based on Cu and Ni films by the method of secondary ion mass spectrometric analysis (MS-7201 M secondary ion mass spectrometer). Films of alloys with a thickness of up to 130 nm were obtained on polished glass substrates with a pre-applied Al buffer layer by simultaneous separate evaporation of the components in a vacuum of 10 – 4 Pa. Copper was evaporated from a strip of tungsten foil with a thickness of 0.05 mm. Nickel was evaporated by the electron-beam method using an electron diode gun. The rate of condensation was 0.5-1.5 nm/s. The purity of evaporated metals was at least 99.98 %. Ar+ ions with an energy of 5 keV were used as probing primary ions. The results of qualitative mass spectrometric analysis of secondary ions indicate the high purity of the films (absence of hydrides, oxides and carbides of Cu and Ni). The elemental composition of the films is represented by isotopes Ni58, Ni60 and Cu63, Cu65. The ratios of isotopic intensities are INi 58/INi 60 = 2,6 and ICu 63/ICu 65 = 2,3, which corresponds to the natural distribution of nickel and copper isotopes. The ratio of isotopic intensities ICu 63/INi 58 practically does not change over the entire thickness of the sample. It was shown that the quantitative analysis of the elemental composition of film alloys can also be carried out by the method of secondary ion mass spectrometry. [ABSTRACT FROM AUTHOR]

To investigate the improvements in the resistance of Cu–Ni alloys to surface pitting corrosion, Cu–Ni thin films containing Al were fabricated via DC magnetron sputtering. The morphologies of the fabricated samples were obtained using a scanning electron microscopy, which yielded information on the crystal size and sample surface before and after corrosion tests. X-ray diffraction was employed for the structural characterization of the as-deposited films, and vibrational spectroscopy was used to verify the corrosion products. The corrosion behaviors of the Cu–Ni and Cu–Ni–Al samples were examined using electrochemical polarization and cyclic corrosion tests. The Al co-deposited samples showed a refined crystal size as compared to the Cu–Ni sample, suggesting that they are more susceptible to the formation of a passivation film. The corrosion current density of the Cu–Ni–Al was reduced, and the corrosion potential was lower than that without Al content. The negative shift in the corrosion potential of the Al-containing samples indicates that the Al2O3 film suppressed the cathodic reaction, resulting in a decrease in the corrosion rate. These results are consistent with the cyclic corrosion test results, in which no pitting corrosion is observed in the Cu–Ni–Al sample. [ABSTRACT FROM AUTHOR]

In this investigation, Cu–Ni alloys with different aluminum additions were synthetized under a vacuum atmosphere to reduce the material density. Annealed alloys in a He atmosphere with low aluminum concentration exhibited a coarse dendritic structure, while samples with high aluminum concentration exhibited a refined dendritic structure. Structural defects analyses have shown relatively low vacancy concentrations. Hardness evaluations indicated an increment by approximately 5 times i.e., 370 HVN, more than that for the alloyed samples compared with the as-cast and unalloyed samples. Compression tests have shown a noticeable strengthening improvement (360 MPa), mainly in samples heat treated with 10 at.% Al, while samples with 5 at.% Al showed an acceptable resistance (270 MPa) as well. In general, the sample with 10 at.% Al presented the best performance to be considered as potential structural material. [ABSTRACT FROM AUTHOR]

Under the combination of certain corrosive ions and stress, Cu-Ni alloys may experience severe stress corrosion cracking (SCC), which causes premature failure and hinders their further applications as crucial construction materials in various engineering fields. To reveal the origin of such failure, minimize the related negative impacts, and achieve economic and social benefits, this review summarizes all SCC-related issues by making a brief introduction to Cu-Ni alloys, reporting the SCC behavior in various environments, identifying the effects of different factors during SCC, and revealing the SCC degradation mechanisms. S2− and NH4+ are the prominent SCC initiators since the former can combine with Cu+ to form Cu2S as a non-protective corrosion product, while the latter has a great tendency to react with Cu2O/Cu and accelerate the general or local dissolution. Their combination has the most detrimental effect. The SCC mechanisms of Cu-Ni alloys are summarized as film rupture theory and dealloying theory. The related SCC mitigation strategies, including using inhibitors, tailoring alloying elements, and removing/reducing the stress are also discussed. In addition, future directions are made at the end of this paper. [ABSTRACT FROM AUTHOR]

The article presents the results of studying the elemental composition of films of CuNi alloys by X-ray microanalysis (an X-ray microanalyzer based on an energy-dispersive spectrometer, which is part of the REM-103-01 scanning electron microscope). Alloy films 30-150 nm thick were obtained by simultaneous separate evaporation of the components (copper and nickel) in a vacuum of 10–4 Pa. Copper was evaporated from a tungsten foil ribbon 0.05 mm thick. Nickel was evaporated by the electron beam method using an electron diode gun. The condensation rate was 0.5-1.5 nm/s. The purity of the evaporated metals was no less than 99.98 %. The calculated composition of the concentrations of the sample components varied over a wide range. The characteristic X-ray spectrum of the film substance was excited by scanning a section of the film with dimensions of 300 x 300 μm with an electron beam; for thicker films, the size of the scanning area was 1 x 1 μm. Thin Ni films of the same thickness were used as standards for quantitative measurements of the elemental composition of alloy films of a certain thickness. The results of X-ray microanalysis indicate a high purity of the films. Comparison of the calculated concentrations of alloys and the results of measurements by X-ray microanalysis showed that in the region of film thicknesses d < 100 nm, the discrepancy is about 10 %, decreasing to 1 – 3 % for sample thicknesses d > 100 nm. [ABSTRACT FROM AUTHOR]

The action of an electron beam on crystals of tetramethylethylenediaminium nitrilotriacetate [HMe2NCH2CH2NMe2H]2+[HN(CH2COOH)(CH2COO)2]–2, ammonium heptamolybdate tetrahydrate (NH4)6Mo7O24‧4H2O, and polymeric zinc nitrilotrimethylenephosphonate trihydrate (ZnH4L‧3H2O)n, on a lamellar crystal of 2,2'-(ethylenedioxy)di(ethylaminium) trifluoroacetate CF3C(O)O‒+H3N(CH2CH2O)2CH2CH2NH3+‒O(O)CCF3, and on films of the monoethanolaminium salt of ethylenediaminetetraacetic acid [Н3NCH2CH2OH]+2[(OOCCH2)2NCH2CH2N(CH2COOH)2]2– was studied. A Tescan VEGA II electron microscope was used as an exposure tool. The microrelief was examined at magnifications from 500× to 50000×. The survey was carried out at an accelerating voltage of 20 kV and a working distance of 2–8 mm, using secondary (SE) and backscattered (BSE) electron detectors. A copper–nickel alloy and silicate glass were used as the substrate material for the films. The crystals and films were irradiated with an electron beam of various powers, forming an area 20 × 20 μm in size. At low power, the area dimensions are strictly 20 × 20 μm, and the surface remains relatively flat. An increase in the power or in the exposure time while maintaining the power causes an increase in the size by 5 to 34%. The maximum impact causes the formation of defects in the form of cracks, swellings, bubbles, holes, and craters. The elevation of the surface increases with increasing radiation dose. [ABSTRACT FROM AUTHOR]

Copper-based materials have long been used for their outstanding thermal and electrical conductivities in various applications, such as heat exchangers, induction heat coils, cooling channels, radiators, and electronic connectors. The development of advanced copper alloys has broadened their utilization to include structural applications in harsh service conditions found in industries like oil and gas, marine, power plants, and water treatment, where good corrosion resistance and a combination of high strength, wear, and fatigue tolerance are critical. These advanced multi-component structures often have complex designs and intricate geometries, requiring extensive metallurgical processing routes and the joining of the individual components into a final structure. Additive manufacturing (AM) has revolutionized the way complex structures are designed and manufactured. It has reduced the processing steps, assemblies, and tooling while also eliminating the need for joining processes. However, the high thermal conductivity of copper and its high reflectivity to near-infrared radiation present challenges in the production of copper alloys using fusion-based AM processes, especially with Yb-fiber laser-based techniques. To overcome these difficulties, various solutions have been proposed, such as the use of high-power, low-wavelength laser sources, preheating the build chamber, employing low thermal conductivity building platforms, and adding alloying elements or composite particles to the feedstock material. This article systematically reviews different aspects of AM processing of common industrial copper alloys and composites, including copper-chrome, copper-nickel, tin-bronze, nickel-aluminum bronze, copper-carbon composites, copper-ceramic composites, and copper-metal composites. It focuses on the state-of-the-art AM techniques employed for processing different copper-based materials and the associated technological and metallurgical challenges, optimized processing variables, the impact of post-printing heat treatments, the resulting microstructural features, physical properties, mechanical performance, and corrosion response of the AM-fabricated parts. Where applicable, a comprehensive comparison of the results with those of their conventionally fabricated counterparts is provided.

Despite its excellent corrosion resistance, B30 copper–nickel alloy is prone to pitting, particularly when exposed to microorganisms. The mechanism underlying the acceleration of pitting in this alloy is not fully understood. In this study, the acceleration of pitting corrosion in B30 copper–nickel alloy caused by a marine microorganism named Pseudomonas aeruginosa (P. aeruginosa) was investigated using surface analysis and electrochemical techniques. P. aeruginosa significantly accelerated the pitting in B30 copper–nickel alloy, with a maximum pitting depth of 1.9 times that of the abiotic control and a significant increase in pitting density. This can be attributed to extracellular electron transfer and copper– ammonia complex production by P. aeruginosa, accelerating the breakdown of the passivation film. [ABSTRACT FROM AUTHOR]

Strengthening of copper and copper alloys without a significant change in their basic characteristics, such as electrical conductivity, thermal conductivity, deformability, etc., is an important objective in terms of materials science. This can be achieved by evenly distributing micro- or nanoparticles of the chemical compounds having an increased hardness (e.g., intermetallic compounds, oxides, borides, or carbides) in a soft metal matrix. In this study, a procedure has been developed for an in situ synthesis of the Cu–TiC ligature based on the interaction of graphite particles with molten CuxTi. Titanium carbide particles, formed in the liquid metal, do not exceed 5 μm in size and demonstrate good adhesion to the metal matrix (without defects and pores). The applicability of the resulting ligature for strengthening copper-nickel alloys is shown using the Cu95Ni5 system as an example. By introducing a ligature based on 20 vol. % TiC, it became possible to increase the microhardness of as-cast copper-nickel alloy to 98 HV, while the electrical resistivity increased to 0.091 μOhm·m. [ABSTRACT FROM AUTHOR]

Copper and its alloys are known as antimicrobial agents that can be used in public places; however, pure copper has a low wear resistance and tends to lose its gloss relatively fast and stainless steel is still more desirable because of its mechanical properties and stable appearance. In this research, German silver coatings, a copper-nickel alloy, are studied as a superior alternative for pure copper coatings. German silver coating on mild steel substrates and stainless steel with two different surface roughnesses was prepared and placed into water bath up to 6 months to investigate the corrosion and exposure effects on the antibacterial behavior. A range of techniques was used to study the microstructure, surface morphology and mechanical properties such as microhardness, coating bonding adhesion, surface roughness and wettability of the coating. Colony count method was used to measure the antibacterial properties, and samples were tested against influenza A virus to evaluate the virucidal activity. The coating thickness was around 130 µm and contained 15% pores and oxides with splats forming inside the coating structure. Inside each splat, columnar grains could be seen with an average of 700 nm width and 4 µm length. The bonding strength of the coating was about 15 MPa, the hardness of coatings was about 180 HV, and the average surface roughness of the as-sprayed samples was about 10 µm. German silver coatings can destroy both Staphylococcus aureus and Escherichia coli by more than 90% after 6 h of exposure time, and it also has a high-level of virucidal activity against influenza A virus after 2 h exposure time. Antibacterial behavior did not show any significant changes after 6 months of immersing samples in water bath. Thus, thermally sprayed German silver coatings exhibited silvery color for a long period of time, while its antimicrobial efficiency was comparable to pure copper coatings. [ABSTRACT FROM AUTHOR]

A deep eutectic solvent, ethaline (as a typical representative of new-generation room temperature ionic liquids), was used to anodically treat the surface of copper-nickel alloy (55 wt.% Cu). Anodic treatment in ethaline allows flexibly affecting the patterns of surface morphology: formation of stellated crystallites and surface smoothing (i.e. electropolishing) are observed depending on the applied electrode potential. The measured values of roughness coefficient (Ra) well correlate with the changes in surface morphology. Anodic treatment of Cu-Ni alloy in ethaline contributes to a considerable increase in the electrocatalytic activity towards the hydrogen evolution reaction in an alkaline aqueous medium, which can be used to develop new high-efficient and inexpensive electrocatalysts within the framework of the concept of carbon-free hydrogen economy. [ABSTRACT FROM AUTHOR]

The arrangement of various metals in a nanoalloy framework enables the alteration of chemical and physical properties. In this study, the structure, surface, composition and magnetic properties of a copper-nickel alloy thin film that was electrodeposited on a stainless steel substrate at -0.9V and 60oC are examined. During the deposition of the bath temperature, chemical elements copper forms first, followed by the formation of a bimetallic copper-nickel alloy. A nickel-rich alloy that effectively resists oxidation covers the underlying copper. It was found that the copper-nickel films revealed a face-centered cubic structure with crystallites oriented along the (1 1 1) plane including crystallite size, micro-strain, dislocation density, and stacking fault probability. Morphological and film composition characteristics revealed that the deposited films were well adherent to the surface of the substrate with microcracks and stoichiometric ratio. The magnetic properties of the deposited films were estimated. [ABSTRACT FROM AUTHOR]

Data on high-temperature tests for heat resistance of copper–nickel-based powder materials synthesized by spark plasma sintering (SPS) are presented. The features of oxidation of copper–nickel alloys with various alloying elements at temperatures above 1000°C have been studied. On the basis of the results of research, the dependence of the growth rate of the oxide film on the high-temperature oxidation temperature is established, and the influence of alloying elements in the composition of sintered copper–nickel alloys on their heat resistance is considered. It is shown that the highest heat resistance is provided by alloying copper–nickel alloys with aluminum and chromium. For all considered compositions of copper–nickel alloys synthesized by spark plasma sintering, the temperature of 1100°C during a 20-h heat resistance test is the limiting one, since most of the samples are completely destroyed. The scale growth rate for composition Cu–Ni–Cr–Al of 1.49 × 10–3 g/cm3 is lower than the oxidation rate of pure nickel of 3.78 × 10–3 g/cm3 at 1000°C, and these two samples demonstrate the lowest weight gain after testing at 1000°С. For compositions Cu–Ni, Cu–Ni–Cr–C(graphite) and Cu–Ni–Al, the oxidation rate increases by two orders of magnitude; for compositions Cu–Ni–Cr and Cu–Ni–Cr–Si, it increases by three orders of magnitude. Despite an increase in the test temperature to 1100°C, the rate of scale growth on the surface of Cu–Ni–Cr and Cu–Ni–Al specimens remains almost unchanged: 124.01 × 10–3 and 210.43 × 10–3 g/cm3 at 1000°C; 153.44 × 10–3 and 203.87 × 10–3 g/cm3 at 1100°C. Deceleration of the oxidation kinetics of these samples with temperature increase is ensured by formation of an oxide film on the surface, which has a dense structure with good adhesion to the basic material. [ABSTRACT FROM AUTHOR]

In the present work, multi-walled carbon nanotube (MWCNT) nanofiller reinforced copper-nickel alloy (CuNi@MWCNTs) nanocomposites were synthesised by a modified electro-chemical co-deposition followed by compaction and sintering. During this method, CuNi@MWCNTs were co-deposited on a cathode tip at room temperature and collected from the electro-chemical bath in powdered form. Subsequently, the powdered nanocomposites were dried, compacted and sintered to prepare solid pellets. The influence of different amounts (25, 50 and 100 mg L−1) of MWCNT nanofillers in the deposition bath on microstructure, mechanical and anti-corrosion properties of CuNi@MWCNTs nanocomposites was investigated. The microhardness, compressive yield strength and friction coefficient of CuNi@MWCNTs (100 mg L−1) nanocomposites were enhanced by 45.7%, 37.2% and 55.1%, respectively, compared to that of pure CuNi alloy. In addition, the CuNi@MWCNTs nanocomposites obtained also exhibited improved anti-corrosion property in 3.5 wt.% NaCl solution at continuous agitation of 150 rpm and 27°C temperature. Based on the research outcomes, this approach for synthesising CuNi@MWCNTs nanocomposites may be proposed for scale-up industrial trials. [ABSTRACT FROM AUTHOR]

This paper identifies the materials used to make a brocade belt belonging to the Qajar courtiers in Iran. This belt consists of two fabric types: red support and golden brocade. Accordingly, this paper examined the skin and tannin type, fiber types, dyeing agents, mordant, and metal wrapping of brocade yarns and metal buckle. Technical imaging, ESI–MS, FORS, FTIR and SEM–EDS were used to identify the materials. Multi-band imaging methods included Vis, UVL, IRR, and UVR, in which UVFC and IRFC images were obtained after processing. The results showed that cotton yarn was used in both fabrics. The red fabric yarns were dyed using cochineal and alum mordant. Also, the yellow brocade yarns were dyed using catechins-rich plants, and in this dyeing process, polyphenols and alum have been as mordant. Madder-dyed yarns are also found in parts of the belt. Examination of the metal wrapping of brocade yarns suggests using strips of copper-nickel alloy with a thin layer of gold-silver alloy. This secondary coating protects the copper-nickel strips and increases their golden luster. The leather analysis of the leather parts also indicated the using cattle/calfskin tanned with gallotannins. Belt buckle analysis also shows the use of brass alloy with a high percentage of zinc, leading to a golden sheen and the buckle desired strength. The results show the use of low-cost materials in the manufacture of clothing for the lower levels of the Qajar court. [ABSTRACT FROM AUTHOR]

This paper clarifies the effects of the fluid parameters of flow velocity, impact angle and sand impact frequency on the erosion-enhanced corrosion of 90/10 copper–nickel alloy by combining computational fluid dynamics (CFD) simulation, wire beam electrode (WBE) technology and electrochemical measurements. The results show that under the conditions without sand particles, erosion-enhanced corrosion is dominated by the impact angle and the flow velocity at lower (<0.860 m/s) and higher (2.370~5.644 m/s) flow velocities, respectively, while both the two fluid parameters have noticeable effects on erosion-enhanced corrosion at intermediate flow velocities (0.860~2.370 m/s). In contrast, adding sand particles corresponding to the sand impact frequency can further increase the corrosion current density without changing the effects of the flow velocity and impact angle. It demonstrates that all three fluid parameters show great effects on the erosion-enhanced corrosion of 90/10 copper–nickel alloy under conditions with sand particles. [ABSTRACT FROM AUTHOR]

Al–Ti–Ni composite coatings with different Ti contents (wt% = 20, 25, 30, 35) are prepared on the surface of 90/10 copper–nickel alloy using selective laser melting. The microstructure and phase composition of the coatings are characterized by scanning electron microscopy, X‐ray diffraction, and energy‐dispersive spectrometry, and the corrosion resistance of the four coatings and the 90/10 copper–nickel alloy in 3.5 wt% NaCl solution is investigated. The coatings exhibit a good metallurgical bonding with the substrate, and passive films are formed on the surfaces of the coatings after 6 h of potentiostatic polarization. The coating with a Ti content of 30% has the most compact passive film and the best corrosion protection performance due to the minimal Ti2O3 content in the passive film, which greatly improves the stability of the passive film. The immersion corrosion mechanism of the coating is pitting corrosion. Electrochemical tests show that the corrosion current density of all four coatings is one order of magnitude lower than that of the substrate, and the coating with a Ti content of 30% has the lowest corrosion current density, indicating that this coating could significantly improve the corrosion resistance of the substrate. [ABSTRACT FROM AUTHOR]

In this investigation, Cu–Ni alloys with different aluminum additions were synthetized under a vacuum atmosphere to reduce the material density. Annealed alloys in a He atmosphere with low aluminum concentration exhibited a coarse dendritic structure, while samples with high aluminum concentration exhibited a refined dendritic structure. Structural defects analyses have shown relatively low vacancy concentrations. Hardness evaluations indicated an increment by approximately 5 times i.e., 370 HVN, more than that for the alloyed samples compared with the as-cast and unalloyed samples. Compression tests have shown a noticeable strengthening improvement (360 MPa), mainly in samples heat treated with 10 at.% Al, while samples with 5 at.% Al showed an acceptable resistance (270 MPa) as well. In general, the sample with 10 at.% Al presented the best performance to be considered as potential structural material.

This work is aimed at studying the effect of Ni content in Cu–Ni alloys on the localization of plastic flow under uniaxial tension. The regularities of localized plastic flow at different stages of work hardening are investigated at different Ni contents in the solid solution via speckle photography method. Particular attention is paid to the effect of Ni content on the duration of the parabolic work hardening stages in alloys. The spatial period of plastic flow localization (the length of the localized autowave) as a function of Ni content in alloys is established as well. [ABSTRACT FROM AUTHOR]

The corrosion behavior of high-strength C71500 copper-nickel alloy in high concentrations of sulfide-polluted seawater was studied by potentiodynamic polarization measurements, electrochemical impedance spectroscopy (EIS), immersion testing, and combined with SEM, EDS, XPS, and XRD surface analysis methods. The results showed that the C71500 alloy shows activation polarization during the entire corrosion process, the corrosion rate is much higher (0.15 mm/a) at the initial stage of immersion, and the appearance of diffusion limitation by corrosion product formation was in line with the appearance of a Warburg element in the EIS fitting after 24 h of immersion. As the corrosion process progressed, the formed dark-brown corrosion product film had a certain protective effect preventing the alloy from corrosion, and the corrosion rate gradually decreased. After 168 h of immersion, the corrosion rate stabilized at about 0.09 mm/a. The alloy was uniformly corroded, and the corrosion products were mainly composed of Cu2S, CuS, Cu2(OH)3Cl, Mn2O3, Mn2O, MnS2, FeO(OH), etc. The content of Cu2S gradually increased with the extension of immersion time. The addition of S2− caused a large amount of dissolution of Fe and Ni, and prevented the simultaneous formation of a more protective Cu2O film, which promoted the corrosion process to some extent. [ABSTRACT FROM AUTHOR]

The effect of the nickel content in commercial copper-nickel alloys (manganine, cupronickel, constantan, monel) on the mechanical properties and parameters of macroscopic plastic strain localization under uniaxial tension is studied. The evolution of plastic strain localization in the yield plateau and parabolic work hardening stages is studied by digital speckle photography. The effect of the Ni content on the onset and duration of the parabolic strain hardening stage is shown. The dependence of the spatial period of plastic strain localization of the alloys on the Ni content in the studied alloys is established. [ABSTRACT FROM AUTHOR]

Cu-Ni/CNT nanocomposites with varying quantities of carbon nanotubes (CNTs) were synthesized via mechanical alloying. Subsequently, the nanocomposite powders were consolidated through cold pressing and sintering. The microstructure, CNT distribution, hardness, and electrical properties were evaluated using XRD, FESEM, hardness testing, and the four-point probe techniques. A homogeneous Cu-Ni alloy with an average particle size of 30 nm was obtained after 10 h of ball milling. Addition of 5 wt.% CNTs resulted in a significant 21.5% increase in density, a notable 142.9% enhancement in macro-hardness, and over 50% reduction in electrical resistivity. Optical micrographs demonstrated that CNT incorporation effectively inhibited matrix grain coarsening, corroborated by microhardness measurements indicating uniform CNT distribution within the copper-nickel matrix, facilitated by the milling process. [ABSTRACT FROM AUTHOR]

Effective interaction potentials suitable for Cu/δ–Ni2Si and Cu/β–Ni3Si are developed. We optimise the potential parameters of an embedded atom method potential to reproduce forces, energies, and stresses obtained from ab initio calculations. Details of the potential generation are given, and its validation is demonstrated. The potentials are used in molecular dynamics simulations of shear tests to study the interactions of edge dislocations with coherent δ–Ni2Si and β–Ni3Si precipitates embedded in a copper matrix. In spite of significantly different crystallographic structures of copper and δ–Ni2Si which usually result in circumvention of dislocations, we also observed cutting processes in our simulations. Dislocations cut for a specific orientation of the δ–Ni2Si precipitate and in some cases where dislocation loops originating from previous circumvention processes are present in the glide plane. It is found that β–Ni3Si precipitates have a similar effect on precipitation strengthening as δ–Ni2Si. Dislocations usually cut β–Ni3Si but increased coherency strain can lead to circumvention processes. [ABSTRACT FROM AUTHOR]

Pressed steel with adjustable (regulated) austenitic transformation (RAT) is used for the hot deformation of a copper-nickel alloy at operating temperatures > 850°C (above the critical point A3 = 850°C). We recommend to extend the temperature range of forged steel with RAT (4Kh4N5М4F2 grade) and to use it in the martensitic state at operating temperatures < 630°С. For this purpose, we study the phase-structural state of this steel after optimized temperature modes of heat treatment (hardening and tempering). The relationship between the parameters of crystal structure and the mechanical properties of thermally hardened steel is established, as well as the temperature mode of hardening used for the process of primary recrystallization of steel with RAT. We compare the parameter of crystal structure and mechanical properties of the analyzed steel with the corresponding characteristics of two operated forged die steels, namely, steel for hot deformation of H13 grade (ASTM, USA; its analogs are the 4Kh5МF1S steel according to GOST 5950-2000, and SKD6 steel according to JIS, Japan) and 4Kh4N5M4F2 steel with RAT used to produce large-size wheels (extruders) for the hot deformation of copper. We justify the temperature mode of tempering for the process of softening of forged steel with RAT. Based on the established relationship between the parameters of crystal structure and hardness, it is shown that, at room temperature, the level of hardness should be lower than 40 HRC. [ABSTRACT FROM AUTHOR]

The effect of Fe/Mn content on the metallographic structure, mechanical properties, and corrosion resistance of 90/10 copper–nickel alloy using electrochemical methods, scanning electron microscope, energy dispersive spectroscopy, X‐ray photoelectron spectroscopy, Tafel experiments, and electrochemical impedance spectroscopy measurements were investigated in this paper. The experimental results indicated that the tensile strength of the alloys increases from 326 to 347 MPa with the change of Fe/Mn content, the yield strength of 90/10 copper–nickel alloys is approximately 150 MPa, and the elongation of the alloys was reduced from 51% to 37%. Moreover, as corrosion proceeds, the corrosion product film was mainly composed of Cu2O, Cu2(OH)3Cl. In addition, the Cu–10Ni alloy with Fe/Mn content of 1.69/0.69 has good corrosion resistance properties. [ABSTRACT FROM AUTHOR]

Due to its high thermal and chemical stability, excellent dielectric properties, unique optical properties, corrosion resistance, and oxidation resistance, the two-dimensional hexagonal boron nitride (h-BN) is often used in a thermal conductor protective layer in deep ultraviolet light-emitting detector fields. However, due to the complicated growth conditions of h-BN, it is often necessary to prepare h-BN by the CVD method in a high vacuum environment, which is limited to a certain extent in terms of film size and production cost. In order to solve this problem, we proposed a method to prepare h-BN thin films by atmospheric CVD (APCVD). This method does not need a vacuum environment, which reduces energy consumption and cost, and makes the operation simpler and the experimental environment safer. The preparation of high-quality h-BN film was carried out using a Cu-Ni alloy as the growth substrate. The growth process of h-BN film was studied, and the influence of growth parameters on the structure of the h-BN film was explored. The morphological features and elemental composition pairs of the samples were characterized and analyzed, which confirmed that the high-quality h-BN film could be successfully grown on the Cu-Ni alloy substrate by APCVD. The UV detection device prepared by using the prepared h-BN film as the photoresponse material had good photoresponse characteristics and performance stability. It provides a new idea for the low-cost preparation of large-scale h-BN. [ABSTRACT FROM AUTHOR]

[Display omitted] Developing electrocatalysts for efficient reduction of nitrate contaminant to value-added ammonia as energy carrier is a pivotal part for restoring the nitrogen cycle. However, the selectivity of ammonia is far from satisfaction, often suffering from accumulation of toxic nitrite byproduct. Herein, a series of CuNi alloy nanoparticles embedded in nitrogen-doped carbon matrix (CuNi/NC) with hierarchical pores were fabricated by pyrolysis of bimetallic metal–organic frameworks (MOFs). The catalysts exhibited excellent selectivity (94.4%) and faradaic efficiency (79.6%) for nitrate reduction to ammonia, greatly outperforming the performance of monometallic Cu/NC (selectivity of 60.8% and faradaic efficiency of 60.6%). Impressively, the introduction of nickel distinctly suppressed the production of toxic byproduct of nitrite. Online differential electrochemical mass spectrometry (DEMS) and in situ surface-enhanced infrared absorption spectroscopy (SEIRAS) tests were utilized to reveal the key intermediates and the reaction pathway. Density functional theory (DFT) calculations demonstrated that the introducing of nickel into copper lattice modified both the electronic and geometric structures of the catalysts. The copper and nickel sites in the CuNi alloy catalysts operate synergistically to facilitate the hydrogenation of NO 2 * to HNO 2 * and suppress the hydrogen evolution reaction, boosting the selective formation of ammonia. This work could provide a new synthetic route for bimetallic catalysts and mechanistic understanding for nitrate to ammonia reaction. [ABSTRACT FROM AUTHOR]

The article presents data on heat resistance high-temperature tests of powder materials based on copper–nickel. The features of oxidation of samples of copper–nickel alloys with various alloying elements have been studied. Compaction of samples of copper–nickel alloys was performed by spark plasma sintering (SPS). The dependence of the growth rate of the oxide film on the temperature of high-temperature oxidation was established, and the effect of alloying elements in the composition of the samples on their heat resistance was considered. On the basis of the results of studies, the dependence of the oxide film growth rate on high-temperature oxidation and the influence of alloying elements in the composition of sintered copper–nickel alloys on their heat resistance was considered. It was determined that, for all the considered compositions of copper–nickel alloys synthesized by spark plasma sintering, the temperature of 1000°C of 20-h test for heat resistance is not the limiting one, since the samples retain their integrity. It is shown that simultaneous alloying of copper–nickel alloys with aluminum and chromium provides the highest heat resistance. The rate of growth of scale for composition Cu–Ni–Cr–Al is 1.49 × 10–3 g/cm3, which is lower than the oxidation rate of pure nickel of 3.78 × 10–3 g/cm3 at 1000°C. These two samples demonstrate the lowest weight gain after testing at 1000°С; for compositions Cu–Ni–Al, Cu–Ni–Cr–Si, and 50 wt % Cu–50 wt % Ni, the oxidation rate increases by two orders of magnitude; for compositions Cu–Ni–Si and Ni, it increases by three orders of magnitude. [ABSTRACT FROM AUTHOR]

Hence, it is absolutely essential to investigate the corrosion and mechanical behavior of metal materials, aspects which mainly include corrosion fatigue [[3], [5]], stress corrosion cracking [[6], [8]], erosion corrosion [[9]], hydrogen-induced cracking [[10]], wear corrosion [[18]], etc. Many high-strength metal-related materials and structures work under the coupling condition of harsh corrosion environments and complex loading [[1], [3], [5], [7], [9], [11], [13], [15], [17]], and related failure cases have been reported extensively all over the world. References 1 Liu M. Effect of uniform corrosion on mechanical behavior of E690 high-strength steel lattice corrugated panel in marine environment: A finite element analysis. Crucial attention was paid to the effect of severe plastic deformation on the corrosion behavior of a tantalum-tungsten alloy [[24]]; the severely deformed crystallographic orientations in the tantalum-tungsten alloy could be greatly weakened by an electrochemical process and could reduce the corrosion rate. [Extracted from the article]