Copper alloys esfera. copper-alloys including GRCop-84, GRCop-42, C-18150, and C-18200 under NASA, industry, and combined funding1. Copper alloys esfera

 
copper-alloys including GRCop-84, GRCop-42, C-18150, and C-18200 under NASA, industry, and combined funding1Copper alloys esfera  Based on the typical demand for advanced copper alloys by emerging industries and major engineering projects, such as electrical engineering, electronics, 5G communications, new energy vehicles, aerospace, and rail transit, this study systematically summaries the current status of international and domestic copper alloy industries, including high-strength and high-conductivity copper alloy

Thomas,2 and J. A useful test for such embrittlement is a hot bend test conducted at 600 °C, the. depending on alloy type, water chemistry, contaminants, oxygen content, pH value, microbial activity, temperature, flow rate, duration of exposure etc. L. Copper alloys are known for their excellent corrosion resistance, but it is not entirely immune to corrosion. Easily identifiable because of its iridescent, golden red color, copper and its alloys, have been used by humans for thousands of years. In order to systematize this colorful collection and provide a basis for specification, the National Association of Architectural Metal Manufacturers (NAAMM) and the National Ornamental & Miscellaneous Metals. process; silver plating of beryllium copper alloys can be more expensive than other copper alloys. Metal ores are generally oxides, sulfides, silicates (Table 12. Four processes to consider when joining. depending on alloy type, water chemistry, contaminants, oxygen content, pH value, microbial activity, temperature, flow rate, duration of exposure etc. 1 INCH COPPER HALF BALLS - HEMISPHERE-110 ALLOY (25 PACK) $34. Select the alloy (s) and one or more properties you would like to see displayed. 01 and 0. This high-strength, exceptionally corrosion-resistant. (CDA) is the market development, engineering and information services arm of the copper industry, chartered to enhance and expand markets for copper and its alloys in North America. Those are suitable to serve different purposes in many sectors. 300 mm in length. The high-copper alloy family includes, in wrought forms, cadmium coppers (C16200 and C16500), beryllium coppers (C17000-C17500), chromium coppers (C18100-C18400), zirconium copper (C15000), chromium-zirconium copper (C14500) and combinations of these and other elements. Figure 3. The effect of aging processes on the tensile properties of C-18150 copper alloy samples, made by laser powder-bed-fusion additive manufacturing (AM) process with three different fabrication orientations (horizontal, angled, and vertical to the build direction), are investigated. 18 μΩ-m. All copper beryllium alloys are readily machinable using conventional processes and the guidelines provided in this brochure. The single phase alloys have excellent ductility, and are often used in the cold worked condition for better strength. 00. By contrast, the recycling of aluminum requires only 2. C19400), copper-zinc alloy that is commercial bronze (Copper Alloy UNS No. Copper and its alloys represent 6 - 9% by weight (or approximately 50 - 55 lb, 23-25 kg) of the content of a typical automobile. 9% of the following bacteria within 2 hours of. It is nobler than aluminum alloys, carbon and galvanized steel and less noble than stainless steels and titanium alloys. A typical example is 60-40 yellow brass, designated as C85500. In addition, Fig. More than 2,800 artifacts have been recovered from the site, including a ship's bell with a date of 1498, an important copper-alloy disc marked with the royal coat of arms of Portugal and the "esfera armilar"(armillary sphere) - a personal emblem of King Manuel I, and an extremely rare silver coin known as the "INDIO", first minted in 1499 by. 01 and 0. Laboratory testing shows that, when cleaned regularly, EPA-registered antimicrobial copper alloy surfaces kill greater than 99. Tin brass is a member of the brass alloy family that includes copper, up to 40% zinc, and up to 3% tin. , strip, rod, wire, bar, tube and plate) as cast billet and as casting ingot. Copper square bars are available in 12 or 72 in. Working and finishing techniques, alloy families, coloration and other attributes are addressed, illustrating that copper and its alloys are so adaptable that they can be used in a multitude of applications in almost every industry, from door handles to electrical circuitry to heat exchangers. 1: Copper-Base Alloy - C27000 (Yellow brass) 11. Cryogenic Properties of Copper. 5% lead. coli was. Alloying produces a metal harder than either copper or zinc individually. The charge on the inner conductor is uniformly-distributed with density. A wide variety of copper alloys are available for use in construction. It is found in ore deposits around the world. Brush Alloy 25 is the most commonly specified beryllium copper and is available in the wrought forms listed on page 5. Copper alloys containing 1 to 6% Pb are free machining grades, and are used widely for machined parts especially those produced in screw machines. 3% cobalt. Pure copper and copper alloys are easy to solder and braze, allowing them to cleanly join with other metals. Silver Plating of C182 (Chromium) Copper Chromium copper is alloyed with a small percentage of chromium (~ 0. 5. 5Ag (wt-%) alloy, by adding Zr to a ratio of Cu–3Ag–0. Details of of copper alloy compositions are given in the Appendix. CDA's website is an excellent resource for information about copper, copper alloys, and their many uses and benefits. a group of alloys with the same characteristics in respect of their field of application, behaviour in contact with drinking water and restrictions with regard to water composition and/or surface area. It is obvious that the conductivity of these alloys is a function of the amount of zinc they contain. An aluminium alloy (or aluminum alloy; see spelling differences) is an alloy in which aluminium (Al) is the predominant metal. Alpha–beta aluminum bronzes are heat treatable. From 1982 through today, pennies are 97. At 22 °C only the highest copper alloy (95 wt. Free shipping on many items | Browse your favorite brands. 10g – 21g. In comparison, typical AF coatings on ships’ hulls initially release copper at a rate of about 50 µg cm −2 d −1 (Earley et al. In 2011, the corrosion and biofouling performance of 11 copper alloys produced by several manufacturers in the United States, Germany and Japan was evaluated in a 12-month. 6. 5) than in saliva fluid (pH 7. Copper alloys vary widely in their resistance to velocity, with C95500 being the most resistant of the cast alloys, C72200 the most resistant. When there is more silver than copper, 92. 9% of the following bacteria within 2 hours of. In fact, copper alloys become stronger and more ductile as the temperature goes down, retaining excellent impact resistance to 20 K (-253 C or -424 F). Good corrosion resistance. 1. Job shops. This technique involves using a brazing filler metal to join two pieces of copper or copper alloys together. Brass is a copper alloy with zinc as the. On the periodic chart, its atomic number is rated 29 with the. If the conductivity of copper-30% zinc. , Ni–Cr) on steel and zinc-based castings. In this review, several typical copper alloys, such as Cu-Fe-P, Cu-Ni-Si, and Cu-Cr-Zr are analyzed. These alloys are available as ingot, strip, bar, tube and wire in various tempers. It has good reflectivity but lacks the refinement of an applied mechanical surface. Permanent mold and pressure die castings of plumbing components are also commonly made of the leaded yellow brass alloy C85800, which contains nominally 1. This specification 2 establishes requirements for an alloy having a composition of copper, tin, lead, and zinc, used for component castings of valves, flanges, and fittings. Malleability Malleability is a measure of a material’s ability to deform below compressive stress. 5 and 1. Below is a breakdown of the copper grade numbering system to help you understand copper alloys and the characteristics of each series. For the majority of nonferrous alloys, this is from about 325–650 °F (165–345 °C), although some alloys require higher aging temperatures. 001 mm/y), within those velocities that each alloy can tolerate without damage to the protective corrosion product film. 22mm – 3″ square. This Standard includes: (a) pressure-temperature ratings Publisher Summary. 08. Annealing of alpha-bronzes is carried out in the temperature range of 550–870 °C. 95% Cu, 0. Production of Alloy Powders. Properties of Copper Powder. Higher tensile strength and hardness can only be obtained when the alloys are cold worked. Shabestari et al [5] Investigate the effect of copper and solidification condition on the microstructure and mechanical properties of Al-Si-Mg alloys . It offers high conductivity, good ductivity and strength. Thermal Conductivity Btu/ sq ft/ ft hr/ °F at 68°F. Metals which have a designated minimum copper content of 99. They offer a wide range of properties, including excellent electrical and thermal. Note that for leach rate. With the aim of obtaining copper alloys with favorable mechanical properties (high strength and high ductility) for various engineering applications, the microstructural characteristics of two conventional copper alloys — an aluminum bronze (AlBC; Cu–Al 9. Only a few metals have a success story similar to that of copper and its alloys. Copper was the base material due to its ability to function as. Copper is known to possess certain unique qualities that make it the best engineering material for bearing applications. Because of the properties it confers on other metals (i. EPA as antimicrobial. Joining. ] A list of components that may be fabricated out of Antimicrobial Copper Alloys - Group I is specified below. 2 Use—The alphanumeric code is used to. The electronic interconnect industry's average scrap weight is approximated at 43%. 300 °C. 3. This is a type of embrittlement caused by absorption of hydrogen. 82%), tin (5. While this variation is quite a lot less than that for strength and conductivity, it should not be ignored. comOFHC Copper (CDA 10200) OFHC copper has 99. com. Copper Alloys as Determined by Ishiwara. The plate was heat treated (F) at 960°C. Depending upon the application requirements, copper beryllium alloys are available in two alloy classes: High Strength (C17000, C17200, C17300) and High Conductivity (C17410, C17460, C17500, C17510). 3. copper-alloys including GRCop-84, GRCop-42, C-18150, and C-18200 under NASA, industry, and combined funding1. The most popular form of pure copper is the standard electrical wire grade of copper (C11000) contains 99. 3 –Fe 3. Within these two categories, the compositions are grouped into the following families of coppers and copper alloys: Coppers. 1) or "native" metals (such as native copper) that are not commonly concentrated in the Earth's crust, or "noble" metals (not. The Copper Development Association Inc. The alloys are used in aircraft and aerospace applications, as well as in high-performance sporting goods. What Is Copper Alloy? Copper alloy (copper alloy) is an alloy formed by adding one or more other elements to pure copper as the matrix. 6 kg of CO2 for each kilogram of metal. These affect copper alloys and are all related to the leaching out of alloy constituents (the alloys are obvious as they appear in the DM title). Gunmetals are copper alloys with tin, zinc, and lead. Typical uses include bus bars or any electrical conductor, and it may be specified as a special copper magnet wire conductor. A ABNT NBR 15827 foi elaborada no Comitê Brasileiro de Máquinas e Equipamentos Mecânicos (ABNT/CB-04), pela Comissão de Estudo de Válvulas em Geral (CE-04:009. Therefore, they are widely used in the chemical, oil, and marine industries for manufacturing of various components of equipment, such as: drill collars, pumps, valves, impellers, fixtures, pipes,. The temper will determine just how malleable the copper sheet will be. 3). 4. 1. For the as-fabricated C-18150 AM parts, horizontal and angled. Powder Size Chart. In both media, migrations are higher for lead than for other metals. Kushal Copper Corporation. The best known traditional types are bronze, where tin is a significant addition, and brass, using zinc instead. Copper alloys vary widely in their resistance to velocity, with C95500 being the most resistant of the cast alloys, C72200 the most resistant. Copper Alloys. Free shipping on many items | Browse your favorite brands. Brown or black can be used as a base color for copper patina. From the early days, copper had a decisive influence on the evolution of mankind and it has been the material of choice promoting the key growth industries of each era. There are two principal classifications, namely casting alloys and wrought alloys, both of which are further subdivided into. C100 Series (Coppers) 100 series coppers are considered pure coppers, having a minimum copper content of 99. Number ranges available for positions 3, 4 and 5. 1 ). (CDA) is the market development, engineering and information services arm of the copper industry, chartered to enhance and expand markets for copper and its alloys in North America. It is found in ore deposits around the world. Pitting - Pits are discrete sites of corrosion at areas where the protective surface film is damaged or breaks down. Interstitial alloys. Copper alloy refers to a group of materials that are formed by combining copper with one or more other elements, such as zinc, tin, nickel, aluminum, or silicon. If the copper-lead alloys do not have sufficient load-carrying capacity, the lead content is reduced, and tin is added to improve the strength. For example, a specific alloy might assume its maximum strength by aging for 5 h at 325 °F (165 °C. 4 Mechanical Properties of Copper and Copper Alloys 671 4. 5% Mg, and 0. Raw Materials. The resistance of brasses to corrosion by aqueous solutions does not change markedly as long as the zinc content does not exceed about 15%. It contains 18% chromium and 8% nickel. Available sizes are 1/8" to 12" diameters in both regular and extra strong wall thickness. 001 mm/y), within those velocities that each alloy can tolerate without damage to the protective corrosion product film. 1069 Stinson Drive Reading, PA 19605. 01–0. This zinc copper alloy may also contain minor amounts of other elements such as iron, nickel, silicon, or aluminum. 78%). F. It also has good conductivity and tensile strength as it can be stretched without breaking. 6 to 2. Dmitry Sergeev. B164-03(2019) Standard Specification for Nickel-Copper Alloy Rod, Bar, and Wire . The microstructure of the single phase brass alloys, with up to 32% zinc, consists of a solid solution of zinc and alpha copper. In both media, migrations are higher for lead than for other metals. The basic properties of copper alloys are largely influenced by the properties of copper itself. 5% copper. products made from Antimicrobial Copper Alloys - Group I under EPA Registration Number 82012-1. Copper alloys with 1. Tough Copper Alloys INC. Basic modern brass is usually 67% copper and 33% zinc, but the compositions of the elements may vary (55% to 95% for copper and 5% to 45% for zinc). Copper (Cu) and its alloys are prospective materials in fighting covid-19 virus and several microbial pandemics, due to its excellent antiviral as well as antimicrobial properties. We offer this material in Ingot, shot, and cut pieces. The as-received copper alloys were processed by solution treatment, water quenching, cold-drawing and ageing treatment successively. This grave contains c. Copper also forms an important series of alloys with aluminum, called aluminum bronzes. Cold-rolled copper products—including sheets, coils, rods, bars, and some plates—are produced with an “as fabricated” finish. Long-term steady-state corrosion rates for most copper alloys in seawater range between 0. Copper-lead alloys containing about 30% lead are stronger but have less satisfactory surface properties and are usually used with a thin lead-tin overlay. 78 wt% Cr and 0. If more complicated bends are required or lightly hammering or shaping will be performed, H00-H01 (1/8-1/4 hard) will be the best option. Both make up a considerable amount of the copper alloys used in art and architecture. Toll Free: 800-57-HEYCO Tel: 610-926-4131. Copper itself is essential for the full wiring harness, alternator and starter motor windings and other motors and actuators. There are more than 400 copper alloys, each with a unique combination of properties to suit many applications, manufacturing processes and environments. Of the various brasses, the most important for connectors are those containing 15 and 30% zinc, although a 5% zinc version is occasionally considered. In this research, we choose a beryllium-copper alloy to make the LPF for its outstanding properties of elasticity, fatigue resistance and fracture strength [32]. A new alloy was needed to fulfil these conditions and Rocketdyne developed a copper alloy based on their previous work with NARloy-A, a cast Cu-3. Copper is used as a conductor of heat and electricity, as. Cast Copper Alloy Threaded Fittings: Classes 125 and 250 ISBN: 9780791833834 - Pag:40 This Standard covers cast Class 125 and 250 copper alloy threaded pipe fittings with provisions for substituting wrought copper alloys for plugs, bushings, caps, and couplings in small sized sizes. They can occur in copper alloys by surface contamination or. Figure 1. Copper Alloys. These other alloys are types with higher silver. The following datasheet gives details about UNS C18150 chromium. Cast copper alloys with between 2% and 11% Sn and 1–10% Zn are termed gunmetals. This alloy is known as cartridge brass. High-strength and high-conductivity copper alloys play essential roles in various industries, including the automotive industry, the railway industry, and the electronics industry [1, 2]. Abstract. Section snippets Alloy design framework. 09/20/2018 EN (English US) 2/26 P308+P313 - If exposed or concerned: Get medical advice/attention. Size Range. It can be coupled to tin and aluminum bronze. The common trade name of this alloy is 85-5-5-5; the correct. The metal is an essential trace. Copper Tin Alloy Properties. 8 –Ni 2 –Mn 0. Copper alloys like bronze, brass and cupronickel combine many qualities to form new metals. Rend. The property of the alloy varies as the zinc percentage changes. The high. coinage. Copper & Brass. Aluminum bronze castings are annealed at 620–670 °C. Environmental Protection Agency as the first solid antimicrobial material. Satin and Mirror Finishes. Fortunately in the UK we use the metric system to weigh up scrap metal. Aluminum Bronzes. 2 Fracture Toughness 673 4. 5. If the copper-lead alloys do not have sufficient load-carrying capacity, the lead content is reduced, and tin is added to improve the strength. Figure 9 34 demonstrates the galvanic series of different commercial alloys in flowing seawater. These alloys are available in different shapes such as waffle plate, rod in coils, and ingot. The development of a new type of environmentally friendly, ultrahigh strength, high stress relaxation resistance, good formability, and high reliability conductive elastic copper alloy has become a research focus for elastic materials. Alloy C18000, another member of the group, contains nickel,. Alloys also tend to be lighter in weight than pure copper because they contain a mixture of lighter elements such as. 3% and 96%. Copper-nickel - Alloyed with Nickel. The main difference between alloy vs. Copper-nickel Alloy. Copper alloy C22000 (commonly known as Commercial Bronze) is a popular architectural metal and was chosen for the 18-ft-high bronze panels in the Ohio Holocaust and Liberators Memorial by Daniel Libeskind. Some alloying elements affect stress relaxation more than others. Brass, for example, is a substitution alloy based on copper in which atoms of zinc replace 10–35 percent of the atoms that would normally be in copper. . Because of this, it is an excellent material for bathroom fixtures, doorknobs, and medical applications. coinage. It consists of 99. Brass is a copper-zinc alloy. 20. % Ag-0. This was followed in 1968 by the construction of the Asperida. 61 shipping. The proportions of the copper and zinc are varied to yield many different kinds of brass. It is used where ease of welding and brazing are especially important. ;. Venn diagrams of seven samples in Yap Trench based on 16S rRNA gene sequencing at a distance of 0. Copper and its relevant species, such as oxides and many alloys, have been recognised as potential antibacterial surfaces. The data compilation is based on articles published since 1993 and consists of about 1830 records. 0. C10300. Gunmetal - Alloyed with Tin, Zinc and Lead. Sometimes called cupronickels, there exists a range of different copper-nickel alloys possessing different properties and useful in a range of different applications. Korea ASEM Corporation Ltd, 109 Jeda-dong, 26-8, 1 Gil, Seungsam, Gyeong-ju Korea Telephone: +82 010 3650 2744. (Thermo; Experimental) Google Scholar. Covers production, consolidation, strengthening, copper in iron and steel P/M parts, and non-structural applications. %) and their UNS (Unified Numbering System) code. Anchor Bronze & Metals, 3. It is also the oldest metal known to man and was first discovered and used about 10,000 years ago. Electrochemical studies and microstructure analysis of directionally solidified hypoeutectic and eutectic aluminum-copper alloys were performed. Due to its effectiveness as an electrical conductor, copper is now most. 5 gives temperature changes concerning this copper alloy for cylindrical contact for one indentation test. The other key properties exhibited by Copper and its alloys include: ~ Retention of mechanical and electrical properties at cryogenic temperatures. Citation 2014). Non-ferrous metals. From: Encyclopedia of Materials: Science and Technology, 2001. 95% minimum copper (silver counted as copper) and is produced by converting cathodes in a continuous casting and rolling process into copper rod. 27. Interstitial alloys. Copper has been an essential material to man since pre-historic times. From 1982 through today, pennies are 97. Metal ores are generally oxides, sulfides, silicates (Table 12. In addition, all three types are affected by cold deformation,. 3 Physical Properties of Copper and Copper Alloys 671 4. Here are the top-ranked copper alloy companies as of November, 2023: 1. . Long-term steady-state corrosion rates for most copper alloys in seawater range between 0. Forms: 2-20 Ingot. Granular copper powder can be produced by a number of methods, the most important being atomization, electrolysis, hydrometallurgy and solid state reduction. 5wt% has been used in A356 aluminum alloy and cast atOne of the major issues with dental implants is failure due to bacterial infection, and additions of copper are known to improve the antimicrobial properties of Ti alloys. Material Groups. 001 mm/y), within those velocities that each alloy can tolerate without damage to the protective corrosion product film. Alloying produces a metal harder than either copper or zinc individually. It offers high conductivity, good ductivity and strength. Coppers in the 100 series are called pure coppers. Flared fittings for use with flared copper tube for cold water applications with a maximum water pressure of 175 psig are manufactured to the requirements of ANSI/ASME B16. They were tested by the Cryogenics Div. * = alloys registered with U. It is used for plumbing fixtures, musical instruments, and decorative items. Brass, for example, is a substitution alloy based on copper in which atoms of zinc replace 10–35 percent of the atoms that would normally be in copper. 8 –Ni 2 –Mn 0. This metal’s hygienic properties make it useful to slow down the growth of bacteria like E-coli, legionella and. There are times when iron will be added into copper alloys to provide positive. Excellent electrical conductivity. promovendo uma caracteristica de deslizamento da esfera, reduzindo o coeficiente de atrito entre a esfera e a. An alloy is a material made by melting one or more metals together with other elements. Copper beryllium alloys are used for their high strength and good electrical and thermal conductivities. 6. ρl = Q + l. This is an alphabetical list of alloys grouped according to base metal. They have high resistance against corrosion. IndiaCopper alloys containing 1 to 6% Pb are free machining grades, and are used widely for machined parts especially those produced in screw machines. The use of the ISO designation is increasingly widespread, applied and deepened by the UNI EN 1412 standard (Copper and copper alloys - European numerical designation system). 3. 100 90The mechanical properties of copper-nickel alloys show a combination of good tensile strength and excellent ductility when annealed. With increasing zinc content, the reddish copper color changes to the yellow of brass. Higher tensile strength and hardness can only be obtained when the alloys are cold worked. 8) and a brass (HB: Cu–Al 4 –Zn 25 –Fe 3 –Mn 3. 11000. 52Hir: M. 3 Solidification cracking. Tube drawing has been successfully demonstrated with tubes as small as 0. Copper alloys are metal alloys that have copper as their principal component. Typical is a 74Cu-22Pb-4Sn composite. 3. Copper and copper alloys are one of the major groups of commercial metals. The copper-zinc brasses consist of a series of alloys of copper up to about 40% Zinc. 4989. 16 bn during 2022-2026, accelerating at a CAGR of 3. Copper is a part of many coinage metals. O Projeto circulou em Consulta Nacional conforme Edital nº 12, de 21. 8 kWh of energy and emits only 0. 02. Copper alloys are metal alloys that have copper as their principal component. It. III. Cast Copper Alloy Threaded Fittings: Classes 125 and 250 ISBN: 9780791833834 - Pag:40 This Standard covers cast Class 125 and 250 copper alloy threaded pipe fittings with provisions for substituting wrought copper alloys for plugs, bushings, caps, and couplings in small sized sizes. 260 Brass Chemical Properties. S. Malleability and Ductility – copper is easy to work with, mainly when it comes to fabricating and joining. Deep drawing. The CuCrZr alloy plate (40 mm thick) was in hot rolled condition. 95% Cu, 0. IBC has launched copper alloy casting at its new and expanded copper alloy foundry facility in Franklin, Indiana, which marks the effective completion of a two-year consolidation of three production facilities into a single vertically integrated copper alloys manufacturing operation. , GRCop-84, which contains 8 at. Commonly used as downhole tubular components, packers, and other subsurface equipment, it is included in API 5CT as Group 2, Grade L80, Type 13Cr. Low-rate. It is also used for radiator cores, tanks, lamp fixtures. Brasses are copper zinc alloys containing up to about 45% zinc, with possibly small additions of lead for machinability, and tin for strength. The Copper Mariner. 05% Lead (Pb) and 0. 0 mpy (0. ESA experience in copper is mostly, but not exclusively, concentrated in the design of combustion systems and burner for shaft melting furnaces, holding. Copper and its alloys exhibit exceptional corrosion resistance to moisture, saltwater, and a variety of chemicals. API 572 section 8. Figure 3. Introduction Chemical disinfection is state of the art in preventing spread of infectious agents in the healthcare setting. The microstructure of the single phase brass alloys, with up to 32% zinc, consists of a solid solution of zinc and alpha copper. Production and forming methods may affect alloy selection. 6% Mn. R. 5Ag (wt-%) alloy, by adding Zr to a ratio of Cu–3Ag–0. 3kg of gold. A team led by controversial physicist Avi Loeb is combing the ocean floor off the coast of Papua New Guinea for remnants of two meteors that they believe could actually be alien tech. Locations Distributor* $50 - 99. Copper beryllium (Cu-Be) alloys are the most efficient system due to their exceptional combination of high strength, good electrical and thermal conductivity, good. Basically, tin coatings are produced by either. , 234, 830–832 (1952). The main concern of HSHC Cu alloys is how to strengthen the alloy efficiently. Nielsen, Jr. Only a few metals have a success story similar to that of copper and its alloys.