Influence Of Copper Addition Research Articles

Influence of Copper Addition on the Mechanical Properties and Corrosion Resistance of Self-Hardening Secondary Aluminium Alloy AlZn10Si8Mg

Aluminium alloys have a wide range of applications, mainly due to their advantageous strength-to-weight ratio, denoted as specific strength and corrosion resistance. In recent decades, there has been a notable surge in the usage of recycled alloys, attributed to their reduced production costs and emissions. One of the conditions for secondary production is the optimal sorting of used scrap. Once the aluminium scrap has been melted, it is tough to reduce the content of the various additives. Copper is the primary alloying element in some aluminium alloys, which leads to an increased amount of copper in the aluminium scrap. Therefore, it is important to investigate its effect on the properties of aluminium alloys in which it is not commonly present. For this reason, this paper is concerned with the influence of copper on the microstructure and properties of the secondary aluminium alloy AlZn10Si8Mg. Specifically, it compares two melts of self-hardening AlZn10Si8Mg alloys differing in copper content (0.019% and 1.72%). A complex quantitative and metallographic analysis by optical and electron microscopy has been performed. Mechanical properties were investigated by tensile test, Brinell hardness, and Vickers microhardness measurements. The corrosion resistance of the individual melts was verified by the Audi test.

Influence of Copper Addition on Microstructure, Mechanical and Thermal Properties of Al-Zn-Mg Alloys

Influence of Copper Addition on Microstructure, Mechanical and Thermal Properties of Al-Zn-Mg Alloys

Influence of copper content on the structure and properties of aluminium alloys

Designing new aluminium alloys always requires an assessment of the influence of modified contents of the main alloying additions on the required properties for a specific application. The aim of this study was to develop a new alloy with a higher tensile strength than the tensile strength obtained in typical 6xxx series alloys, with a satisfactory hot extrusion ductility. The article presents the results of studies on the influence of copper additions, in three variants, on the structure and mechanical properties of extruded aluminium profiles in various heat treatment states. The base reference for the presented studies was the following aluminium alloys: AlMgSi (EN AW-6063) and AlCuMgMn (EN AW-2017). On this basis, three alloy variants with Cu contents of 2.5, 3.5 and 4.5 weight % were selected. These alloys were cast by vertical semi-continuous casting in the form of ingots with a diameter of 100 mm. Hot deformation studies were carried out in the process of co-extrusion on a semi-industrial line consisting of a horizontal 5 MN press together with auxiliary devices. The extruded profiles were free from defects that could have resulted from the process, such as overheating, cracks and blisters. The materials in the form of extruded profiles, in the heat treatment states T1 and T4, were characterised in terms of structure and mechanical properties. The variants with Cu contents of 2.5 wt% and 3.5 wt% had comparable structure and grain size, and the variant with 4.5 wt% Cu had a finer microstructure. For the studied alloys after heat treatment, higher the strength, higher the Cu content in the alloy, ranging from 445 to 543 MPa. It has been found that it is possible to develop modified aluminium alloys based on the 6xxx series with an increased copper addition (but still below the content typical for Al alloys of the 2xxx series) that will have a strength above 400 MPa. The first variant of the new alloy with a Cu content of 2.5 wt% meets the set goal and meets the requirements set at the beginning of the studies.

Influence of Copper Addition on Microstructure, Mechanical and Thermal Properties of Al–12.6%Zn–Mg Alloys

Influence of Copper Addition on Microstructure, Mechanical and Thermal Properties of Al–12.6%Zn–Mg Alloys

Effect of Cu on Performance of Self-Dispersing Ni-Catalyst in Production of Carbon Nanofibers from Ethylene

The development of effective catalysts for the pyrolysis of light hydrocarbons with the production of carbon nanomaterials represents a relevant direction. In the present work, the influence of copper addition on performance of a self-dispersed Ni-catalyst and structural features of the obtained carbon nanofibers (CNFs) was studied. The precursors of Ni and Ni-Cu catalysts were prepared by activation of metal powders in a planetary mill. During contact with the C2H4/H2 reaction mixture, a rapid disintegration of the catalysts with the formation of active particles catalyzing the growth of CNFs has occurred. The kinetics of CNF accumulation during ethylene decomposition on Ni- and Ni-Cu catalysts was studied. The effect of temperature on catalytic performance was explored and it was shown that introduction of copper promotes 1.5–2-fold increase in CNFs yield in the range of 525–600 °C; the maximum CNFs yield (100 g/gcat and above, for 30-min reaction) is reached on Ni-Cu-catalyst at 575–600 °C. A comparative analysis of the morphology and structure of CNF was carried out using electron microscopy methods. The growth mechanism of carbon filaments in the shape of “railway crossties” on large nickel crystals (d > 250 nm) was proposed. It was found that the addition of copper leads to a decrease in the bulk density of the carbon product from 40–60 to 25–30 g/L (at T = 550–600 °C). According to the low-temperature nitrogen adsorption data, specific surface area (SSA) of CNF samples (at T < 600 °C) lies in the range of 110–140 m2/g, regardless of the catalyst composition; at T = 600 °C the introduction of copper contributed to an increase in the specific surface of CNF by 100 m2/g.

Influence of copper addition on corrosion properties and hardness of Al–Cu/Al two-layered-structure composites

An experimental investigation has been observed on hardness, sintered density and corrosion behaviour of two-layered structured Al-xCu/Al sample through powder metallurgical route under hot compaction condition. The samples were prepared with different percentages of Cu content (x: 5 wt. %, 10 wt. % and 15 wt. %) in the aluminium matrix with a constant pressure of 400 MPa with different hot-pressed temperatures (500 °C, 550 °C and 600 °C) at a dwelling time of 3 h. The developed two-layered samples microstructure was analysed using the optical and scanning electron microscope. The highest value of micro-hardness (100.6 HV) was obtained at interface region of 15% of copper at 550 °C. The corrosion rate of Al-Cu/Al two-layered samples at the interface were analyzed through the potentiodynamic polarization test and found that with addition of copper content the susceptibility of corrosion increases. The Electrochemical Impedance Spectroscopy (EIS) test was conducted to know the equivalent circuit model, which provides a minimum chi-square value and that circuit model taken as best-fit circuit model. From the EIS results, it was found that 10 wt. %Cu sample circuit provides minimum chi-square value.

Influence of copper addition on the properties of equiatomic NiTi shape memory alloy prepared by vacuum induction melting method

In this study the effect of Cu addition on the phase transformation behavior, microstructure, and micro hardness of equiatomic Ni-Ti shape memory alloy was investigated. NiTiCu SMA prepared with the composition (52.119 % at. Ni, 41.731% at. Ti and Cu 6.15 % at.) and compared with the properties of the equiatomic NiTi SMA with composition (50% at. Ni, 50% at. Ti). Vacuum induction melting method used in the preparation of Both SMAs. The Differential Scanning Calorimetry, Scanning Electron Microscope, X-ray Diffraction Analysis, optical microscope and vicker’s microhardness test was used to investigate the characteristics of the equiatomic NiTi and NiTiCu SMAs. The results revealed that when Cu element was added the phase transformation temperatures decreased below body temperature. NiTi matrix phase and Ti2Ni secondary phase exist in both SMA samples, also Cu-rich phase appeared in NiTiCu SMA and this is one of the reasons that lead to increasing the microhardness of alloy when Cu element was added. The value of equiatomic NiTi increases from 238.74 to 329 when Cu element was added (for NiTiCu alloy) after heat treatment.

Decoupling pyrite and arsenopyrite in flotation using thionocarbamate collector

Thionocarbamate collectors are noted for their high flotation selectivity against pyrite under alkaline condition. In this study, selectivity of O-isopropyl-N-ethyl thionocarbamate (IPETC) is investigated in decoupling flotation response of pyrite and arsenopyrite under single mineral and artificial composite systems. The influence of copper addition, collector adsorption behaviour and mineral surface speciation on flotation response were characterised using complementing electrokinetic and spectroscopic techniques. The results showed no pyrite and arsenopyrite flotation at pH 11 until CuSO4 (2.5 × 10−5 mol/l) addition where arsenopyrite displayed remarkably good, CuSO4 concentration dependent flotation response relative to pyrite. Collector concentration (> 4 × 10−6 mol/l IPETC) had little effect whilst the flotation response was highly pH dependent. The preferential IPETC adsorption on copper-treated arsenopyrite at pH ≥11, yielding 90% arsenopyrite and 11% pyrite concentrate recovery, was ascribed to chelate formation between sulphur and copper and a synergistic coordination of the σ bond of arsenic and deprotonated nitrogen of IPETC.

Influence of Copper Addition in AlSi7MgCu Alloy on Microstructure Development and Tensile Strength Improvement

Commercial AlSi7Mg alloy represents the usual choice for complex geometry casting production. The market imperative to improve mechanical properties imposed the design of new chemical composition of AlSi7MgCu alloy with high content of Cu (up to 1.435 wt.%). This represents a challenge in order to achieve advanced properties. The interaction of a number of alloying (Si, Mg, Cu) and trace elements (Fe, Mn) influenced a wide range of complex reactions occurring and therefore leading to intermetallic phase precipitation. The characterization of novel chemical composition interaction and its solidification sequence was achieved by modelling an equilibrium phase diagram, simultaneously performing both thermal analysis and metallographic investigations. Copper influence was indicated in the whole solidification process starting with infiltration in modified Chinese script phase Al15(Fe,Mn,Cu)3Si2, beside common intermetallic Al5FeSi. Copper addition encourages formation of compact complex intermetallic phases Al5Cu2Mg8Si6 and Al8(Fe,Mn,Cu)Mg3Si6. Solidification ended with secondary eutectic αAl + Al2Cu + βSi. Microstructure investigation allows volume reconstruction of the microstructure and distribution of particular phases. Chemical compositions enriched in copper content and developed microstructural constituent through solidification sequence of AlSi7MgCu alloy contribute to a significant increase in mechanical properties already in an as-cast state.

Influence of Copper Addition on Mechanical Properties and Microstructure of Eutectic Al-12Si-Xcu Alloy Produced Through Powder Metallurgy Process

Influence of Copper Addition on Mechanical Properties and Microstructure of Eutectic Al-12Si-Xcu Alloy Produced Through Powder Metallurgy Process

Influence of Copper Additives on Heat Capacity and Thermodynamic Functions of A7E Brand Aluminum

The economic feasibility of applying aluminum as a conductor is explained by the favorable ratio of its cost (which has remained almost constant for many years) to the cost of copper. When using conducting aluminum alloys to fabricate thin wire, winding wire, etc., some difficulties can appear in connection with their insufficient strength and small number of kinks before fracture. In recent years, aluminum alloys have been developed which possess strength characteristics, making it possible to apply them as conductors even in the soft state. One promising consumer of aluminum is the electrotechnical industry. From here, the development of new compositions of alloys based on this metal is very urgent. The temperature dependence of the heat capacity of A7E aluminum alloys with copper is determined experimentally and the variations in their thermodynamic functions are calculated. Investigations are carried out using computers and the Sigma Plot program. Polynomials of the temperature dependence of the heat capacity and variations in thermodynamic functions (enthalpy, entropy, and Gibbs energy) of these alloys and a reference alloy (Al of the A5N brand), which have the correlation coefficient Rcorr = 0.992–0.998, are established. It is shown that heat capacity of A7E brand aluminum decreases with an increase in the copper content and increases with an increase in temperature. The enthalpy and entropy of alloys of A7 brand aluminum with copper increase with an increase in the copper fraction and decrease with an increase in temperature. The inverse dependence is characteristic of the Gibbs energy.

Evaluation of the Microstructure and the Electrochemical Properties of Ce0.8(1−x)Gd0.2(1−x)CuxO[1.9(1−x)+x] Electrolytes for IT-SOFCs

The influence of copper addition (0.5–2 mol%) on the crystal structure, densification microstructure, and electrochemical properties of Ce0.8Gd0.2O1.9 synthesized in a one-step sol–gel combustion synthesis route has been studied. It has been found that Cu is very active as sintering aids, with a significative reduction of GDC firing temperature. A reduction of 500 °C with a small amount of copper (0.5 mol%) was observed achieving dense bodies with considerable ionic conductivities. Rietveld refined was used to investigate the crystal structure while relative density and microstructural examination were performed in the sintering temperature range of 1000–1200 °C after dilatometer analysis. High dense bodies were fabricated at the lowest sintering temperature, which promotes the formation of Ce0.8(1−x)Gd0.2(1−x)CuxO[1.9(1−x)+x] solid solution and the absence of secondary phase Cu-rich or the segregation or copper at the grain boundary. As compared to the pure GDC an improvement of total conductivity was achieved with a maximum for the highest copper content of 2.23·10−3–9.19·10−2 S cm−1 in the temperature range of 200–800 °C.

THE influence of copper addition on crack initiation and propagation in an Al–Si–Mg alloy during cyclic testing

The effect of copper (Cu) addition up to 3.2 wt% on crack initiation and propagation in an Al–Si–Mg cast alloy was investigated using in-situ cyclic testing in the as-cast condition. A combination of digital image correlation, electron backscatter diffraction, and scanning electron microscopy was used to investigate crack initiation and propagation behaviour during in-situ cyclic testing. The results showed that Cu-rich intermetallic compounds with the addition of Cu up to 1.5 wt% do not affect the fatigue behaviour of these alloys, and that crack propagation in these cases is trans-granular and trans-dendritic. However, increasing the concentration of the Cu retained in the primary α-Al matrix in solid solution and Cu-containing precipitates delayed crack propagation during cyclic testing. The results showed that strain accumulation was highest at the grain boundaries; however, the crack preferred to propagate along or across primary α-Al dendrites due to the relatively lower mechanical strength of the matrix compared to the eutectic and intermetallic phases. Moreover, the addition of Cu of more than 3.0 wt% to Al-Si-Mg alloys changes the fatigue behaviour that a rapid failure occurs.

Influence of Copper Addition on Sigma Phase Precipitation during Hot Deformation of Duplex Steel.

The paper presents an experimental study on microstructure changes in duplex steel after hot deformation. Duplex steels and cast steels are characterized by a multiphase microstructure. They are relatively new materials with great contributions to the many fields of industries. Due to the fact of deforming two different phase austenite and ferrite those materials have a complex plasticity. This work is a continuation and complementation of previous works and is a significant supplement to information presented in them. The article concerns precipitation phenomena and changes in the microstructure of two grades of ferritic-austenitic steels: X2CrNiMoN25-7-4 and X2CrNiMoCuN25-6-3. Those steels have a very similar chemical composition, differing by only 2.5% copper content. An important aspect presented in the work is we observed that adding 2.5% copper prevented precipitation of the destructive sigma phase during the hot deformation.

The Influence of Copper Addition on Crack Initiation and Propagation in an Al-Si-Mg Alloy During Cyclic Testing

The effect of copper (Cu) addition up to 3.2 wt.% on crack initiation and propagation in an Al-Si-Mg cast alloy was investigated using in-situ cyclic testing in the as-cast condition. A novel combination of digital image correlation, electron backscatter diffraction, and scanning electron microscopy was used to investigate crack initiation and propagation behaviour during in-situ cyclic testing. The results showed that Cu-rich intermetallic compounds with the addition of Cu up to 1.5 wt.% do not affect the fatigue behaviour of these alloys, and that crack propagation in these cases is trans-granular and trans-dendritic. However, increasing the concentration of the Cu retained in the primary α-Al matrix in solid solution and Cu-containing precipitates delayed crack propagation during cyclic testing. The results showed that strain accumulation was highest at the grain boundaries; however, the crack preferred to propagate along or across primary α-Al dendrites due to the relatively lower mechanical strength of the matrix compared to the eutectic and intermetallic phases. Moreover, the addition of Cu of more than 3.0 wt.% to Al-Si-Mg alloys changes the fatigue behaviour such that an almost static failure occurs, with limited crack propagation.

The influence of copper addition on the electrical conductivity and charge transfer resistance of reduced graphene oxide (rGO)

The possible explanations on how the existence of copper, CuO, or Cu2O influences the electrical conductivity and electrochemical properties of rGO.

Influence of copper additions on materials properties and corrosion behaviour of Al–Mg alloy sheet

Abstract Additions of a few tenths of a percent of Cu to Al–Mg alloys give rise to a noticeable age-hardening effect. This can be utilized to overcome the softening during paint curing of conventional Cu-free Al–Mg alloys of the AA 5xxx series for car body applications. In the present study we explore this effect in sheet material of the Al–Mg–Cu alloy AA 5023. Mechanical properties and formability of AA 5023 sheet were determined and compared with results obtained in the Cu-free alloys AA 5019 and AA 5182. The resistance to corrosion, viz. general pitting behaviour, filiform corrosion and, most notably, intergranular corrosion was probed. As to the latter, TEM analysis was performed to assess type, composition and spatial arrangement of grain boundary phases causing intergranular corrosion in AA 5xxx series alloys. The results are discussed as a function of alloy composition, recrystallized grain size as well as final heat treatment, i.e. batch annealing vs. continuous solution heat treatment.

The Influence of Copper Additions and Aging on the Microstructure and Metastable Pitting of Al-Mg-Si Alloys

The metastable pitting of 6xxx series aluminum alloys (Al-Mg-Si-(Cu)) as a function of Cu content and aging was studied. Potentiodynamic polarization and potentiostatic transients were performed to...

Influence of Copper Addition on Structure and Hardness of the ZnAl40Cu3 Alloy after Heat Treatment

The effect of heat treatment on the structure and hardness of the ZnAl240Cu3 alloy is presented in the paper. ZnAl40 and ZnAl40Cu3 alloys were tested. The scope of the examination included: dilatometry, structural and hardness tests. There are two transformations taking place during the heating and the reverse transformation during cooling. Most important for the alloy is the first transormation which occurs at lower temperatures (from 104°C to 131°C). There are found, that long-term soaking at 185°C results in a significant decrease in the hardness of the ZnAl40Cu3.alloy. The reason for the observed decrease in the hardness of the ZnAl40Cu3 alloy by soaking at a temperature of 185°C is primarily disappearance of dendrites.

Influence of Copper on Redistribution Behaviour of Boron in Titanium Stabilized and Low Carbon Steel as Observed by Neutron Induced Alpha Autoradiography

Boron content and its distribution play a significant role in modifying the metallurgical and mechanical properties of many steels and alloy at lower level of concentration. Precipitation of boron at the grain boundaries, have shown to improve the creep strength in titanium stabilized steel, high temperature ductility in low carbon corrosion resistant steel and the hardenability in low carbon steel in general. Titanium-stabilized steel (DIN 1.4970), was developed as a possible material for fast breeder sodium-cooled nuclear reactor core components for its superior creep strength, high micro-structural stability and elevated void swelling resistance. It is well known that, helium produced during neutron irradiation through the 10B(n,α)Li7 reaction, affects the mechanical properties and the amount of void swelling in nuclear reactor materials. Two nos. of Ti-stabilized steel samples with 40ppm boron and 2ppm boron (DIN 1.4970 & DIN1.4970LB steel) were analyzed for boron re-distribution behavior during different thermo-mechanical treatment using a technique known as Neutron Induced Alpha Autoradiography (NIAA). This technique is a well known technique, and widely used for revealing the spatial distribution of boron in the materials with a resolution approaching to ppm level. This technique has also been used to detect the influence of copper addition on boron distribution pattern in steel specimen. Mapping of boron autoradiography of Low carbon steels containing 20ppm of boron with and without copper was able to demonstrate this behavior. Boron track mapping of Low carbon steel without copper, in solution annealing treatment, show the uniform distribution of boron throughout the matrix, whereas when the similar steel with 1.48% copper was mapped, it shows the precipitation of boron at the grain boundaries.