Initial Corrosion Behavior of Element Copper in Atmospheric Environment20200718 20724 1gtqufa (original) (raw)

Wear Behavior of Commercial Pure Copper with Al and Zn under Dry, Wet and Corrosive Environment

2020

Introduction Copper and copper alloys constitute one of the most important groups of commercial metals. They are familiar materials that are extensively used in industrial applications due to their excellent electrical and thermal conductivities, outstanding resistance to corrosion, ease of fabrication, and good strength and fatigue resistance [1-4]. Unalloyed copper is quite soft compared to common structural metals. An alloy with aluminium added to copper is known as aluminum bronze; the resulting alloy is stronger and harder than either of the pure metals. When zinc is added to copper form alloys known as brass. It should be noted that neither 'bronze' nor 'brass' is a concrete, technical term. Tin, manganese, nickel, and silicon can also be added to make stronger copper [5, 6]. Another copper strengthening method is precipitation hardening. The process involves quenching a supersaturated solid solution from an elevated temperature, then reheating to a lower temperature to allow the excess solute to precipitate out and form a second phase [7]. The second phase can be a metal or an inter-metallic compound precipitated from a solid solution by an ageing treatment [8-10]. Copper based materials also used as bearing materials because they have high thermal and electrical conductivity, self-lubrication property, good corrosion and wear resistance [11, 12]. However, the major failure of copper is its surface wear, which induces the surface's deformation, lowering the strength and hardness of copper materials compared to other materials. Therefore, there has been a great demand for improving the performance of its surface [13, 14]. There are several studies and investigations dealing with wear resistance improvements of these materials. Wear resistance is one of the most important properties of these alloys. The wear response of the alloys significantly depends on their alloying

Performance of Cu and Cu-Zn alloy in the Arabian Gulf environment

Materials and Corrosion-werkstoffe Und Korrosion, 2010

Corrosion performance of copper and brass coupons during 15 month exposure in atmosphere, underground and splash zone conditions was undertaken at Khaleej Mardumah test site located in the industrial/coastal city of Jubail along the Arabian Gulf coast, Saudi Arabia. The environmental indicators such as soil, groundwater, seawater, and air particulate samples were assessed. The exposed corrosion coupons were examined by scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and X-ray fluorescence (XRF) to identify the corrosion products and study their surface morphology. Corrosion rate was determined by weight loss method. The experimental results indicated that a high degree of variation in temperature and humidity in this region combined with high chloride and sulfate concentrations was primarily responsible for the corrosion of copper and brass at Khaleej Mardumah test site. Underground environment was the most corrosive to both copper and brass coupons studied, followed by splash zone. Corrosion rates were found to range from 4.29 to 10.84 µm/y for copper and from 2.47 to 29.31 µm/y for brass. Corrosion rates of copper and brass obtained in this study are also compared with those reported for other locations worldwide.

COMPARATIVE CORROSION BEHAVIOR OF PURE COPPER AND BRASS IN 3 . 5 % NaCl SOLUTION

Copper and brass are used in many economic sectors as electrical, construction, transport and others. From common household electrical wiring to boat propellers and from photovoltaic cells to saxophones, copper and its alloys are employed in a variety of end-uses. Copper tubing is now the standard material for potable water and heating systems in most developed countries. This is in part due to its bacteriostatic properties, or in other words due to the ability of copper to inhibit the growth of bacterial and viral organisms in water. Therefore, the corrosion resistance of copper and brass are important in defining the field of use as construction parts. This paper aims at investigating the comparative corrosion behavior of pure copper and brass in 3.5 % NaCl solution. The corrosion behavior of both type samples in 3.5% NaCl solution was investigated by the use of electrochemical methods as open circuit potential and linear polarization resistance measurements. The results show an i...

Influence of increasing zinc contents in brass in the early stages of corrosion investigated by in-situ TM-AFM and SIMS

Analytical and Bioanalytical Chemistry, 2002

In-situ tapping mode atomic force microscopy (TM-AFM), a powerful, high-resolution imaging technique for determining the structure of surfaces and ex-situ secondary ion mass spectroscopy (SIMS), a multielement, high-depth-resolution method, were used to examine the influence of increasing zinc contents in brass in the early stages of corrosion. Four different samples (pure Cu, pure Zn, Cu/Zn=90/10 wt% and Cu/Zn=70/30 wt%) were studied in order to determine their chemical behaviour under various atmospheric conditions. The in-situ TM-AFM investigations were carried out in synthetic air with 60% relative humidity (RH) and 80% RH with 250 ppb SO 2. The samples for the ex-situ SIMS experiments were weathered over a period of 60 h in 80% RH and 250 ppb SO 2. The in-situ TM-AFM investigations have shown that an increasing Zn content in brass increases the corrosion rate. Keywords Corrosion • In-situ measurements • AFM, SIMS • Corrosion kinetics • Weathering Experimental Sample preparation and weathering conditions Specimen of pure copper (Johnson Matthey, Paris/France, max. 25 ppm trace impurities), of pure zinc (Johnson Matthey, Paris/ France, max. 25 ppm trace impurities), and of two brass alloys, Cu/Zn=70/30 wt% (Alfa Aesar, Vienna/Austria, max. 25 ppm trace impurities), Cu/Zn=90/10 wt% (Enzesfeld Caro Metallwerke AG, Enzesfeld/Austria) were mechanically abraded with SiC paper up to 2400 mesh, cleaned ultrasonically in ethanol absolute p.a., abraded afterwards with SiC of 4000 mesh and cleaned again in

Corrosion behaviour of bronze in urban environments: influence of tin content

Corrosion Engineering, Science and Technology, 2013

In this paper, the influence of the tin content on the corrosion behaviour of copper alloys was investigated. Three different bicomponent bronze alloys were exposed to a natural urban environment. The kinetic corrosion processes and the patina properties were monitored using the open circuit potential, electrochemical impedance spectroscopy and spectrocolorimetry. Results show that the bronze corrosion behaviour improves upon increasing the tin content. In addition, the mechanism of the patina formation is different for the three alloys.

Corrosion protection of outdoor bronze: historical quaternary alloy and modern alloy with artificial patination

2016

Outdoor bronzes suffer corrosion phenomena that generate partially protecting layers called patina. In urban atmosphere, the action of the environment makes these patinas partially leached away by rainwater. Moreover, the geometry of exposure influences the corrosion behaviour: in particular, different kinds of patinas are formed in “sheltered” or “unsheltered” areas due to the action of acid rain. These two kinds of patina were simulated through dropping (runoff) and wet&dry (stagnant rain) testing devices in order to obtain representative substrates for the application of protective coatings. However, when considering representative substrates for the application of protective coatings, also artificial patinas such as “liver of sulphur” (based on the use of sulphide solutions), frequently applied by artistic foundries, should be taken into account. The present work reports on chemical and morphological characterisation of (i) historical quaternary bronze (Cu-Sn-Zn-Pb), pre-patinat...

Protection of metals (H.İ.Unal,..,2011)

The corrosion behavior of uncoated brass and electrolytically silver coated brass in cyanide solu tions such as 0.1 M HCl, 0.1 M H 2 SO 4 and 0.1 M H 3 PO 4 was investigated by Tafel polarization curves and cyclic voltammetry curves at 1., 24., 48., 72., 96. and 168. hours. The coating efficiency was calculated by cur rent density of corrosion determined from Tafel polarization curves. Surface analysis of coated brass immersed into acidic solution by 168 hours was done. It is concluded that silver coating is very effective to protect the corrosion of brass for a long time.

Comparative investigation into the corrosion of different bronze alloys suitable for outdoor sculptures

Corrosion Science, 2008

Several bronze alloys, suitable for production of outdoor sculptures, were developed in the frame of the European project "Eurocare-Bronzart". The elemental composition of the alloys was searched to fulfil specific criteria such as: reduction of lead content, good resistance toward corrosion and aesthetic characteristics conformable to artistic purposes. After metallurgical characterization, the resistance toward corrosion was evaluated in artificial environments. Ageing experiments were performed in a salt spray cabinet and in a climatic chamber in the presence of a controlled concentration of SO 2. The Thin Layer Activation (TLA) method was applied to calculate the thickness loss of activated specimens exposed to artificial corrosive atmospheres. After artificial ageing experiments the surface of the materials was investigated by SEM-EDS techniques.The bronze alloys containing diVerent percentage of nickel showed the best properties of resistance toward corrosion.

Physical Behaviour of Thermally Affected Bronze and Brass

Journal of Mechanical Engineering Science and Technology, 2020

The physical behavior of thermally affected cast copper, aluminum bronze and brass has been studied by subjecting to heating isochronally for one hour at a range of 600°C. It shows that solid-solution hardening takes place into the Al added bronze and Zn added brass metal. Due to heating Al forms hard and brittle intermetallic of copper aluminates into the bronze metal which responses some age-hardening effects. The electrical conductivity of the metals increases initially through heat treatment due to stress relieving and finally decreases due to formation of intermetallic precipitates. The color of the heated samples are also studied through tristimulus color parameter 'L*', 'a*', and 'b*' values which were analyzed and evaluated in MATLAB software. It is found that incorporation of Al and Zn affects the color of cast Cu. The overall change of color occurs with increasing heating temperature due to chemical changes like oxidization, intermetallic formation, dissolution of phases, precipitation coarsening and recrystallization. Due to change of hardness and microstructural properties of the experimental metals, the sound intensity level also decreases at high heating temperature. A microstructural study confirms that the cast alloys content the different phases of grains and bring about recrystallized status under heating at 500°C for one hour.