In recent years, scholars pay more attention to powder metallurgy with "nano" and "composite" material properties, while ignoring the basic materials and technology in the field of powder metallurgy in the expanding role. Copper in the field of powder metallurgy played a huge role, will continue to promote its development. This paper describes the application of copper in the field of powder metallurgy and process development, reviewed the history of the development of copper, properties and applications. This article supports this view: the application of powder metallurgy copper will continue to increase, metal powder supplier in the field of thermal management materials and traditional powder metallurgy, its application prospects.

    This paper describes the application of copper in the field of powder metallurgy and process development, reviewed the history of the development of copper, properties and applications. I believe that the application of powder metallurgy copper will continue to increase, in the field of thermal management materials and conventional powder metallurgy and its application prospects.

    The application of copper in the powder metallurgy

    As early as 10,000 years ago, copper was discovered manganese powder as a unique metal and understanding. At first it was used for jewelry and other accessories. Natural copper ore or copper block as a raw material, processing is very simple, that the original cold. Back to 8700 years BC, there is to do with copper pendant necklace.

    Copper has excellent thermal and electrical properties and good corrosion resistance and mechanical properties. Copper can easily be processed into complex shapes and filaments. Architects often use the bright red and eroded after its patina, as buildings, decorative ceiling and outdoor installations.

    Copper alloyed with other elements easily, a large number used to make shaped forgings, castings and powder metallurgy products. The formation of copper and nickel alloys have excellent resistance to seawater corrosion performance. Tin copper solid solution can increase strength and corrosion resistance. Zinc and copper alloys, brass powder that was used for water pipes, locks, fittings, valves, pipe fittings. Containing nickel powder, tin, titanium, beryllium copper powder (FCu) and cobalt alloy strength is equivalent to high-strength steel, and has high electrical conductivity and thermal conductivity. Copper and copper-zinc alloy is often used to produce flakes of powder. By adjusting the tin-nickel composition, can generate a specific color.

    In the field of powder metallurgy, using copper powder production of electronic and thermal components. With tin, zinc, nickel, silicon powder copper or iron alloys are widely used in automotive, lawn park equipment, tools and electronics industries. Copper up to use in self-lubricating bearings, the other is pre-mixed Fe-Cu, the chemical industry of the dialysis parts and friction materials.

    Copper is an important and unique application of powder metallurgy field. The material in this area is not obtained by melting and casting, for example: dispersion strengthened Cu-Al2O3 and manufacturing welding electrodes used to enhance (for automotive and other industries), for the thermal management of electronic components W-Cu and Mo -Cu, these materials need to control their porosity. Self-lubricating bearings and filters is a typical field of application of powder metallurgy. These materials require control of appropriate porosity, oil content in order to achieve excellent lubrication.

    Copper powder by metal injection molding process can be made into complex shapes of electrical and electronic components, the product has good electrical conductivity and thermal conductivity. We can use high-purity copper, by increasing the density of the final parts to improve conductivity and thermal conductivity. Injection molding process can increase the density of copper powder, the product of conductivity and thermal conductivity increases.

    Powder metallurgy products

    The primary application of copper powder, copper-tin powder is mixed to make bronze pieces. In the early 1920s, located in New Jersey Carl Bartlett autonomous metal refining (USMR), began production of electrolytic copper powder. The factory area is small, with a large cathode slot. At peak production, copper powder factory about 455 tons per month. In the mid-1980s, smelting and electrolytic refining businesses forced to close, due to Carl Bartlett plant closures, although some companies trying to produce electrolytic copper powder, copper powder, the United States no longer production. Today, copper powder origin in Europe, Japan, Russia, India and South Korea.

    Dendritic copper powder particles with the characteristics of bulk density by adjusting the process is less than 1 g / cc, green strength than 35MP. Powder by adjusting the deposition process and post-processing, apparent density can be increased.

    In the United States, through the water spray combined with gas atomization process to produce copper oxide reduction, and its shape is spherical or irregular shapes. The physical properties of atomized powders (such as: apparent density, mobility, particle size and green strength) and process conditions, such as: specific additives, melting temperature, atomization pressure, reduction temperature and post-processing of powders. The powder tested by redox median diameter of 10 microns, bulk density less than 1.5 grams / cubic centimeter, Green density greater than 20MP. Atomized powder particle size and the reduction temperature is a key factor in the decision powder products.

    Atomization and redox properties of powder and copper powder in essentially the same application, the application of the exception is the need for the dendritic powder and very low bulk density.

    Processing of self-lubricating oil-bearing copper-tin base (internal pores) is the unique characteristics of powder metallurgy. Such bearings are sintered to a certain density, porosity oil content can reach 10 to 30%. Such bearings require regular lubrication to ensure the safe operation of equipment life cycle. In 1920 the first self-lubricating bearings used in the Buick automobile industry. Used in other industries is quite large, boron powder changing household equipment industry. Manufacturing self-lubricating bearings consume about 55% of copper production.

    Cu-Pb and Cu-Pb-Sn bearings for the automotive, turbine, thrust washers and industrial pumping equipment. Steel backing material has replaced the cast and forged bronze bearings, powder covering the steel substrate by sintering and rolling up to a certain density, the porosity of the final product is less than 0.25%.

    Brass powder production by atomization and nickel silver alloy powder, brass powder, zinc content of 10% to 30%, lead is sometimes added to improve mechanical properties. Pieces in the lock, Instrument pointer and driving equipment has been applied. As beautiful brass color, its being used for decorative metal medals. Weight 2.6 kg of brass powder metallurgy parts for the robot arm has recently been part of. Sintered density of 7.7 grams / cubic centimeter of the sintered tensile strength of 193MPa, elongation rate of 14%. Shows a lot of powder metallurgy powder metallurgy process, the use of copper-based materials are very promising and creative.

    In 2002 estimated world consumption of copper powder at 5.9 ~ 6.4 million tons, 22,000 tons in use in North America, Europe, 1.8 million tons, other countries, consumption of 4,500 tons. Approximately 55% of the copper used in bronze pieces, 13% mixed with iron to produce powder metallurgy parts, 12% penetration of sintered powder, 10% for copper, 10% for other applications such as: friction materials, chemical, W-Cu and Mo-Cu metal, coating, paint, paste and ink.

    Powder production in North America and around the world after the company reorganized. 20 years ago, North America, there are eight copper manufacturer, today has been reduced to four, may shrink further.

    Current development

    Particle size of less than 10 micron powder for injection molding parts production. Injection molding process can be used for electrical and electronic components of industrial production of complex shapes, such material has high conductivity and thermal conductivity. As the conductivity of high purity materials associated with the sintered density, injection molding process can make parts of the density close to the original density of the material, and has a complex shape, made of copper powder in the thermal management device applications. In addition to the complexity of electronic products in copper heat sinks and other cooling components, the article also discusses the loose copper in electronics cooling applications. Ullrich

    Paper studies to obtain high conductivity and thermal conductivity of the necessary conditions. Analysis of the conductivity components in more than 90% of raw materials, extrusion pressure and sintering temperature requirements.

    Growth and iron, as for copper and iron powder pre-mixed expectations will increase 5%. Copper enhances the performance of iron-carbon alloy material, can increase its density, strength, fatigue resistance and mechanical properties. Engstrom (NorthAmericaHoganas) of the papers discussed in several iron-based powder metallurgy how to add a certain amount of copper to improve its properties and microstructure.

    Copper in the device and has a high thermal conductivity and thermal conductivity of the application of powder metallurgy parts are rarely developed. Potential applications include electrical contact elements, short circuit, electric components (for example: slip ring and rotor of the commutator). Electric field components have been used for heat sinks and heat exchangers, will be extended to the electronic cooling system. Parts for electrical and thermal conductivity of copper powder products will reach 15% to 20%.

    With a mixture of iron and copper infiltrated agents use increases, consumption of copper per year to about 25%, copper and tin powders for self lubricating bearings, lock parts and textile pieces for brass parts, bronze alloy powder all over the world continue to consume 50% to 60%.

    Production pipeline industry and other parts of the elbow has developed quite mature. Copper powder manufactured by the economic problems such components should be reviewed again.

    As a beautiful copper color and the excellent performance of atmospheric corrosion, copper is used extensively for decorative purposes, such as: furniture, outer buildings, walls and roofing materials. Copper powder metallurgy applications in such areas should also be considered. Now, from copper and copper alloy powder produced relatively high pressure and large parts have been be used for this field.

    Many wrought and cast copper and copper alloy parts need machining. Lead is often added such products in order to enhance the cutting performance of copper. Lead alloy bearing parts of the processing is becoming a problem, many countries are exerting pressure to reduce lead content. Powder Metallurgy almost no cutting, so the use of its inherent manufacturing process to replace the lead in forging many castings. These components will involve fuse holder, welding electrodes, valves, fasteners, and transmission parts.

    Copper future is bright. Traditional applications such as: self-lubricating bearings, pre-mixed powder, infiltrating agents, brass and bronze alloys, as well as friction materials continue to play an important role in copper consumption is the main area. Thermal and electrical conductivity of copper powder in the field of applications will continue to grow, which will expand the use of copper. Most of the powder metallurgy process in the production of high-density, high thermal conductivity components is feasible in the new powder metallurgy technology needs to be awareness and development of people

    The use of powder metallurgy, powder metallurgy high-speed cutting of production parts and decorative alloy components need to be developed, and only by copper powder made of parts to meet its characteristics. Source:www.mhcmp.com