Influence Of Cu Content Research Articles

Statistical analysis of Cu content effects on structural properties in CuZr metallic glasses

This study examines the effects of casting conditions on the structural properties of CuZr metallic glasses (MGs) using molecular dynamics simulations. The influence of Cu content on various structural properties was explored, finding significant power-law relationships that indicate increased Cu promotes the formation of icosahedra-like structures and enhances the population of solid-like polyhedra. In contrast, the clustering coefficient, reflecting solid-like connectivity, showed a linear relationship with Cu content, revealing that while Cu increases solid-like structures, their connectivity does not scale proportionally. No significant correlations were found for sample volume, cooling rate, or temperature within the studied ranges. This study highlights the utility of statistical analysis in elucidating material property relationships, contrasting with the less interpretable nature of machine learning models. The findings provide valuable insights into the role of Cu content in MGs and demonstrate the importance of traditional statistical approaches for material characterization.

Influences of Cu content on the microstructure and reinforcing behavior of network AlN/Al composites at 350 °C

Reinforcement configuration of Al composites has recently been at the center of attention. In this study, through the analysis of microstructure and tensile properties, effects of Cu content on the reinforcing behaviors of AlN network were investigated in details. Results indicated that the increasing amount of Cu would form micron Al2Cu which would decorated on the AlN network. With the increasing amount of Cu addition from 1.5% to 6%, the particle size of Al2Cu increased from 1 μm to 10 μm. Besides the micron Al2Cu, Cu elements were also existed in θ′ precipitates in the region where were poor of AlN and segregated on the surface of AlN. Given the microstructure changes with different Cu addition, the tensile properties at room temperature increased with Cu addition while the average tensile strength at 350 °C were decreased from 102 MPa to 85 MPa. The addition of elements would affect the bearing capacity of the 8.2AlN/Al–Cu composites at 350 °C. Firstly, the micron Al2Cu phase would suffer the load and get stress concentration. It would lead to the premature imitation of voids and strongly impair the strengthening behavior of AlN network. Secondly, the nano θ′ precipitates would become coarsen and the hinder effects of dislocation would be enhanced at 350 °C. Finally, the segregated Cu atoms on the AlN surface could increase the deformation coordination of AlN network and help decrease the stress concentration.

New methodology for estimating the influence of Cu content of Ferrous Scrap materials in the Total Cost of Operation (TCO) of scrap mix in Electric Arc Furnace steelmaking

Scrap is the main raw material of the electric arc furnace (EAF) route of steelmaking and an important one in the primary route. The decarbonisation commitment acquired by the most relevant steelmaking companies, will only increase the amount of scrap used by both routes, making it a critical component to succeed in the worldwide challenge of reducing CO2 emissions. While being a very relevant material, scrap characterisation is complex due to its heterogeneity, but furthermore, its quality is worsening as its demand increases. This includes the sterile content, such as copper. Higher sterile content scrap comes at a lower price, while scrap with a lower content in undesired elements is most costly. Being able to balance the cost and benefit of purchasing scrap with a higher or lower content of copper with a respective, lower or higher purchase cost would be of interest to optimise the mix and produce the required quality steel at the lowest possible cost. Nowadays, this cost benefit analysis can only be done by performing Total Cost of Operation (TCO) calculations that require a considerable amount of information, including but not limited to the complete chemical composition of scrap, market parameters, production forecast and other relevant data; moreover, involving an arduous optimization process. Based on a parametric study of the TCO calculation, this work proposes a mathematical model to estimate the impact on the TCO of a predefined scrap mix when only modifying the specifics of one given scrap type. The results would facilitate the decision making by comparing the two scenarios as a factor of cost. This mathematical model can be easily programmed and requires only 5 parameters to be run, while providing a low error result.

Balancing act: influence of Cu content in NiCu/C catalysts for methane decomposition.

Thermal catalytic decomposition of methane is an innovative pathway to produce CO2-free hydrogen from natural gas. We investigated the role of Cu content in carbon-supported bimetallic NiCu catalysts. A graphitic carbon material was used as a model support, and we combined operando methane decomposition experiments in a thermogravimetric analyzer with in situ electron microscopy measurements. The carbon yield was maximum with around 30% Cu in the nanoparticles. Adding more Cu drastically lowered the carbon solubility in the metal nanoparticles, which lowered the initial reaction rate and overall carbon yield. In situ TEM measurements showed that the addition of Cu to the catalysts strongly influenced the metal nanoparticle shape and size during carbon growth, and the growth mode. NiCu particles were larger, remained spherical and facilitated steady CNF growth. In contrast, pure Ni nanoparticles fluctuated in shape, sometimes fragmented, and showed stuttering CNF growth. This was ascribed to fluctuating coverage of part of the Ni nanoparticle surface with amorphous carbon, which increased the chance of total encapsulation and hence deactivation of the individual Ni nanoparticles. This supports a picture where balancing the carbon supply, transport, and nucleation of amorphous and crystalline carbon is crucial. Our results also highlight the importance of combining statistically relevant measurements with microscopic information on individual nanoparticles to understand overall catalytic trends from the combined behavior of individual catalyst nanoparticles.

Microstructure and enhanced strength-ductility of TiNbCu alloys produced by laser powder bed fusion

The β-type Ti35NbxCu alloys (x = 0, 1, 3, 5, and 7 wt%) were produced by laser powder bed fusion (LPBF) and the influence of Cu content on the microstructure and mechanical properties was studied. The results indicate that when the content of Cu is less than 3 wt%, Cu can diffuse completely into the Ti matrix to form solid solution without element segregation. Moreover, the elastic modulus of Ti35Nb1Cu alloy (49.1 ± 1.6 GPa) is reduced by 33 % compared to that of Ti35Nb alloy (73.2 ± 1.4 GPa). When the content of Cu exceeds 3 wt%, the eutectoid reaction is activated during the cyclic heating and rapid cooling of LPBF, and the partially supersaturated β phase is transformed into nano-scale α and Ti2Cu phases (β→α+Ti2Cu). Nano-scale Ti2Cu particles precipitated along β grain boundary results in a pinning effect, which inhibits the growth of β grain, hinders dislocation movement, and improves the strength of the alloy. However, when the content of Cu is 7 wt%, the dislocation density (4.179 × 1015 m−2) and the ratio of brittle phase Ti2Cu (8.5 %) are too high, and the stress concentration caused by the initiation of inherent micro-cracks are the main reason for the tensile brittle fracture of Ti35Nb7Cu alloy. As such, the Ti35Nb5Cu alloy has the highest tensile strength of 867.3 ± 24 MPa and the elongation reaches 11.7 ± 0.5 %. Therefore, solution strengthening of Cu, fine grain strengthening of β, dislocation strengthening, and precipitation strengthening of Ti2Cu are the main reasons for the excellent comprehensive mechanical properties of Ti35Nb5Cu alloy.

The influence of Cu content and Mg/Si ratio on the strength and formability in Al-Mg-Si-Cu alloys

The effects of Mg/Si ratio and Cu content on the strength and formability of four 6000 series alloys with Mg-rich and high Cu content were investigated by means of three-point bending testing, tensile testing and hardness measurement, scanning electron microscope and transmission electron microscope. It was addressed that alloys composition affects strength and formability by microstructure including intermetallic particles, grain size, texture and precipitates. The high Mg and Cu contents lead to lower yield strength in T4P temper but higher strength after paint baking due to the formation of large numbers of Cu-containing precipitates. The Mg-rich alloys show better formability which is attributed to the lower fraction of coarse α-AlFe(MnCu)Si intermetallic particles (controlled by the Mg/Si ratio) in these alloys. Additionally, high intensity Cube texture in Si-poor alloys, a feature that is also harmful to hemming performance, was found to compete with particle-stimulated nucleation (PSN). This observation indicates that the influence of coarse intermetallic particles on formability is greater than texture in Mg-rich alloys.

Influence of Cu content on mechanical and tribological properties of Al–7Si–Cu alloy

In this study, Al–7Si–Cu alloys with different contents of Cu were prepared by ultrasonic agitation casting method. The microstructures were characterized by scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS). Dry sliding friction and wear properties with different Cu contents and loads were investigated. The results indicated that the alloy with 3.0 wt% Cu content revealed the optimal microstructure, comprehensive mechanical properties, and tribological properties. The hardness, tensile strength, and yield strength were enhanced by 83%, 57%, and 59%, respectively. The friction coefficient and wear rate reduced by 33% and 24% at 40 N load, respectively. The wear mechanism of Al–7Si–Cu alloy was mainly abrasive wear and delamination wear accompanied by oxidation wear. The improvement of the tribological properties of the alloy was attributed to the combined improvement of the microstructure and mechanical properties.

Maximizing the hydrothermal stability of Cu-LTA for NH3-SCR by control of Cu content and location

Hydrothermal stability is crucial for the application of NOx emission control catalysts on diesel vehicles. In this study, the influences of Cu content and Cu species on the catalytic performance and hydrothermal stability of copper-exchanged LTA (Cu-LTA) zeolite catalysts for the selective catalytic reduction of NOx with NH3 (NH3-SCR) have been systematically investigated. The Cu-LTA(n)−0.41 catalyst with the maximum amount and ratio of Cu2+-2Z species in Cu-LTA, with Cu/Al = 0.41 and Si/Al = 16, was produced by full occupation of Al pairs in the single 6-rings (s6rs) with Cu2+ ions. This catalyst showed higher deNOx activity after hydrothermal aging under extremely harsh conditions of 920 °C for 24 h than any of the other catalysts. The results suggest that maximizing the amount of Cu2+-2Z species and diminishing the formation of comparatively vulnerable [Cu(OH)]+-Z species in the high-silica LTA zeolite is an effective strategy for developing hydrothermally stable NH3-SCR catalysts.

Tailoring the tribology property and corrosion resistance of selective laser melted CoCrMo alloys by varying copper content

In this study, the cobalt-chromium-molybdenum (CoCrMo) alloys containing varying Cu contents (CCM-xCu, x = 0, 2, 3, 4 wt%) were fabricated via the selected laser melting (SLM) method. The influences of Cu content on tribological performance and corrosion resistance were investigated. The 2 and 3 wt% Cu contributed to inhibiting the generation of the HCP phase, whereas the inhibitory effect was quite limited at 4 wt% Cu. Notably, 4 wt% Cu led to the formation of Cr-enrich precipitates in the matrix, which was partially coherent with the Cu nanoparticle. The corrosion resistance of the CCM alloy was enhanced as the 2 and 3 wt% Cu added into the CCM alloy, contrarily, which deteriorated when Cu content reached 4 wt%. For the CCM-2Cu and CCM-3Cu, Cr-precipitates played a major role in enhancing the wear resistance, while the Cu lubrication effect working in coordination with Cr-precipitates determined that for the CCM-4Cu. This study was expected to achieve better tribology and corrosion properties of SLM-produced CCM alloys by tailoring microstructure through the Cu element.

Study on the Influence of Cu Content on Phase Transition Characteristics of Fe75Ni(25-x)Cu x Elastocaloric Refrigeration Alloys

In this study, the mechanical alloying (AM) and powder metallurgy (PM) techniques were adopted to synthesize the Fe75 Ni(25-x) Cu x elastocaloric refrigeration alloys to research the effect of Cu contents on phase transition characteristics and microstructure of Fe75Ni(25-x) Cux elastocaloric refrigeration alloys. The conclusion was drawn that, with increasing Cu content, the phase transition characteristics changed and presented different changing trends. It was found that the phase enthalpy change value was 43.34J/g when the Cu content was 7at%, which was about 1.26 times of Fe15Ni (wt%) alloy. In addition, the FeNiCu alloy was a single-phase alloy with a crystal space group structure of Im-3m when the Cu content was 7at%, and the FeNiCu alloy was a two-phase alloy with crystal space group structures of Im-3m and Fm-3m when the Cu content was more than 7at%. This study provided an experimental basis for the theoretical investigation of the phase transition mechanism of FeNiCu elastocaloric refrigeration alloys.

Construction of antifouling Cu-modified TiO2 coating via micro-arc oxidation: The influence of Cu content

As an effective antimicrobial element, the incorporation of Cu into the surface layer of metallic Ti substrate is regarded as a promising method to enhance its antifouling phenomenon. In this work, a micro-arc oxidation (MAO) process was conducted in an aqueous electrolyte containing Na2Cu-EDTA to produce a Cu-modified TiO2 coating on metallic Ti. The influence of Na2Cu-EDTA concentrations on microstructural feature, corrosion resistance and antifouling capability of the Cu-modified TiO2 coatings were examined. The results indicate that an increased amount of Cu could be incorporated into TiO2 with a higher concentration of Na2Cu-EDTA, which also affects the micro-arc discharge events and, consequently, the morphological features of the coating. The content of incorporated Cu determines the antifouling performance of Cu-modified TiO2 coating, which remains harmless to the corrosion resistance.

Effect of Cu additions on the microstructure, wear resistance and corrosion resistance of Fe-based/B4C composite coating by vacuum cladding

Fe-based/B4C composite coatings with different Cu contents were prepared on the surface of ASTM 1045 steel by vacuum cladding. The influence of Cu contents on the microstructure, hardness, wear behavior and corrosion resistance of coatings was investigated. The results demonstrated that the microstructure was finer owing to the dissolution and dispersion of Cu, although the type of boride M2B and carboboride M23(C, B)6 in Cu-free and Cu-added coatings did not change. Since the Cu additions improved the hardenability of coating matrix and transformed its microstructure into martensite, the microhardness of coating matrix reached over 600 HV, and the macrohardness also increased and reached the maximum of 57.85 HRC for 5Cu sample. The wear volume of Cu-added coating was significantly lower than that of Cu-free coating, and the wear rate of 5Cu sample decreased by 50.40 %. The number of spalling pits on the worn surface decreased, showing the best wear resistance, and the main wear mechanism was fatigue spalling. Furthermore, the coating with high Cu contents possessed higher Ecorr, lower Icorr and higher Rct, which was attributed to the composite oxide passive film formed on the corrosion surface effectively isolated the coating from corrosive medium and greatly improved the overall corrosion resistance of coating.

Influence of Cu content on the hardenability of Al-xCu-1.1Li alloys

The influence of Cu content (3.7 wt%, 4.1 wt% and 4.3 wt%) on the hardenability of Al-xCu-1.1Li alloys was evaluated through a novel end quenching method by using cold-rolled thin sheets combined with strength measurement after subsequent T8 aging. The yield strength of all three aged alloys decreases with the increase of the distance away from the quenching end. The quenching depth decreases with the increase of the Cu content, which was described by the distance of 95% strength retention value of the samples at the quenching end. The intragranular coarse Cu-enriched phase particles formed during the end quenching process impede the precipitation of T1 precipitates and then lead to the strength reduction. The higher Cu content alloy with more and larger Cu-enriched particles inside the grain causes the more decrease in T1 precipitation, which consequently leads to more reduction in strength. The alloy with higher Cu content therefore has lower quenching depth. The coarse Cu-enriched grain boundary phase particles cause the solute depletion around the grain boundary and create PFZ. Based on the time-temperature-properties (TTP) curves, the quench sensitivity increases and the stability of the supersaturated solid solution of the alloy decreases with the rise of the Cu content. Additionally, the coarse Cu-enriched particles within the grain might be coarse Al2Cu particles, which tend to nucleate at the Al3Zr particles.

The Influence of Copper Content on the Elastic Modulus and Antibacterial Properties of Ti-13Nb-13Zr-xCu Alloy

Device-related infection or inflammatory and stress shield are still the main problems faced by titanium alloy implants for long-term implantation application; therefore, it is of great significance to design an alloy with low elastic modulus and good antibacterial properties as well as good biocompatibility. In this paper, Ti-13Nb-13Zr-xCu(x = 3, 7 wt.%) alloys were designed and prepared to reveal the influence of Cu content on the elastic modulus and antibacterial property. X-ray diffractometer, metallographic microscope, scanning electron microscope, and transmission electron microscope were used to study the phase transformation, microstructure, mechanical properties, antibacterial properties, and cytotoxicity of the alloys. The experimental results have demonstrated that the antibacterial performance and the elastic modulus were significantly improved but the corrosion resistance deteriorated with the increase of the copper content. Ti-13Nb-13Zr-3Cu with a low modulus of 73 GPa and an antibacterial rate of over 90% against Staphylococcus aureus (S. aureus) exhibited great potential as a candidate for implant titanium in the future.

Influence of Cu content on the microstructure and mechanical property of Ti3SiC2/Cu composites

Ti3SiC2/Cu composites with different Cu content were prepared by spark plasma sintering (SPS) process in vacuum and the effect of Cu content on the microstructure and mechanical property was investigated. The axial displacement, temperature and current of the composites during the sintering process were recorded and discussed. The phase compositions of the original Ti3SiC2 and Cu powder before and after ball-milling, and the as-produced composites were studied by XRD analysis. The surface morphology and fracture surface of the composites were investigated by SEM. The influence of Cu content on the relative density, hardness and compressive strength of the composites was inquired. The results discovered that the phase composition of Ti3SiC2/Cu composites varied with the content of Cu. The phase composition of the Ti3SiC2/5 vol% Cu composite was composed of Ti3SiC2, Ti5Si3 and Cu3Si, while that of Ti3SiC2/10 vol% Cu composite and Ti3SiC2/15 vol% Cu composite contained TiC, besides Ti3SiC2, Ti5Si3 and Cu3Si. Moreover, the relative density of all Ti3SiC2/Cu composites was relatively high (≥93%). With the increase of Cu content, the axial displacement, hardness and compressive strength of the Ti3SiC2/Cu composites increased. Conclusively, the Ti3SiC2/Cu composite with 15 vol% Cu exhibited better mechanical properties.

Effect of Cu content on the precipitation behavior of Cu-rich and NiAl phases in steel

The nanoscale precipitation and the mechanical properties of the two CuNiAl-containing steels with different Cu contents aged at 500 °C were investigated in this study. Results of mechanical property indicated that the co-precipitation of Cu-rich and NiAl phases during aging contributed to the precipitation strengthening effects. The influence of Cu content on the evolution of precipitates was studied by atom probe tomography (APT). The results demonstrated that the increasing of Cu content enhanced the number density of precipitates and accelerated the precipitation process. The two steels showed two kinds of precipitation sequences on account of different Cu contents. The steel 1 with low Cu content exhibited a precipitation sequence of “supersaturated solid solution → NiAl → NiAl + Cu”, while the steel 2 with high Cu content presented the process of “supersaturated solid solution → Cu → Cu + NiAl”. After further aging, the precipitates of both steels were transformed into Cu/NiAl co-precipitates without isolated Cu-rich phases and isolated NiAl phases. • Hardness of the CuNiAl-containing steel can be improved by increasing the Cu content. • The increasing of Cu content enhances the number density of precipitates and accelerates the precipitation process. • The precipitation sequences of two steels with different Cu contents are clarified.

Influence of Cu content on microstructure, grain orientation and mechanical properties of Sn–xCu lead-free solders

The effect of Cu content on the microstructure, grain orientation and mechanical properties of Sn–xCu (x=0–4.0 wt.%) lead-free solder was studied. Results showed that added Cu induced the formation of intermetallic phases. Only the η-Cu6Sn5 and ɛ-Cu3Sn phases were present in the β-Sn matrix. For all contents, the strongly preferred orientation of the β-Sn phase was formed on the {001} plane. In Sn doped with 1.0 wt.% Cu, the η-Cu6Sn5 phase exhibited the preferred orientation of {0001} plane, whereas doping with 3.0 or 4.0 wt.% Cu transformed the preferred orientation to the {010} plane. In addition, only the {0001} and planes were present in the ɛ-Cu3Sn phase. The high Cu contents contributed to an increased number of low-angle boundaries, high residual strain, tensile strength and microhardness.

The microstructures and mechanical properties of a highly alloyed Al-Zn-Mg-Cu alloy: The role of Cu concentration

The influence of Cu content on microstructures and mechanical properties of a highly alloyed Al-10.0Zn-2.6Mg-xCu-0.15Zr alloy with the Cu content in the range of 0 to 3.0 was studied by OM, SEM, TEM, tensile tests, XRD, and DSC. We determined that the Mg(Zn,Al,Cu)2 (σ) and Al2Mg3Zn3 (T) phases presented in all as-cast alloys, and Al2Cu (θ) phase was found in the alloys with Cu higher than 2.5 wt.%. Also, it is found that the volume fraction of the primary phase increased with the Cu increase. Further, the volume fraction of the residual eutectic phase (REP) increased gradually with the increase of Cu after solid solution, mainly attributed to the low diffusion coefficient of Cu and thus suppressed the dissolution of the second phase. The tensile testing of the aged alloys indicates that the strength of the studied alloys increased significantly with the Cu increase when Cu is lower than 1.0 wt.%, whereas further increase Cu content it decreases. The elongation increases to a peak value fast at low Cu content. After a critical Cu content (1.5 wt.%), a slight decrease is followed. The elongation of highly alloyed Al-Zn-Mg-Cu alloys should consider the coupling effect of grain refinement and REP.

Significant influence of Cu content on the radiation shielding properties of Ge-Se-Te bulk glasses

Bulk metallic glasses have attracted significant attention from researchers and material engineers for several applications. In this paper, we study the influence of Cu content on the radiation shielding properties xCu-(20-x)Ge-40Se–40Te (0 < x ≤ 20 at.%) bulk glasses. These bulk glassy samples are designed by utilizing FLUKA Monte Carlo based on their densities and chemical compositions. For x- and gamma-rays shielding studies, the mass attenuation coefficients (μ/ρ) of the bulk glasses are obtained via photon beam transmission experiment performed based on FLUKA simulations. Furthermore, we evaluate the shielding characteristics of the involved glassy specimens against charged particles and neutrons beam. The obtained findings show that the trend of μ follows the pattern: CGST1 < CGST2 < CGST3 < CGST4 < CGST5 for x = 0, 5, 10, 15, and 20, respectively. However, this trend is more conspicuous in the photoelectric effect dominated energies due to the greater dependence of μpe on the Z of the glasses. The present glassy samples show superior photon absorption capacity, especially CSGT5 sample, as compared to conventional shielding materials. Therefore, they can be deployed for nuclear shielding applications in space and other radiation environments.

Influence of Cu content on the phase composition and thermoelectric properties of deposited Cu-Se films

In this study, the p-type Cu-Se films with different Cu contents were prepared on SiO2/Si substrates by magnetron sputtering using targets with different atomic ratio ([Cu]/[Se]) of Cu to Se. The relation of Cu content and phase composition in Cu-Se films was systematically studied. The deposited films took place phase transformation from p-CuSe2 to p-CuSe2+γ-CuSe, to γ-CuSe, to γ-CuSe+β-Cu2-xSe, to β-Cu2-xSe, to α-Cu2Se+unknown, to α-Cu2Se+unknown+Cu phase with increasing [Cu]/[Se] in the deposited films from 0.49 to 5.74. At room temperature, the carrier concentration decreases in the order of the CuSe2, CuSe and β-Cu2-xSe phase; but the carrier mobility exhibits an opposite trend. In the studied temperature range, the Seebeck coefficient and the power factor decreases in the order of β-Cu2-xSe, CuSe2 and CuSe phase. The [Cu]/[Se] in deposited films with single β-Cu2-xSe phase exceeds 2.0 of stoichiometric lattice and Cu-rich β-Cu2-xSe phase films forms. The deposited Cu-rich β-Cu2-xSe phase film with [Cu]/[Se]=2.65 has an optimum Seebeck and resistivity value, reaching a high power factor of 2.88 mW·m−1·K−2 at RT and 5.91 mW·m−1·K−2 at 320°C. It is of the guidance meaning for the further study the thermoelectric properties of Cu-Se films in the future.