Copper Powder (Atomized Metal) - Weight: 1kg - By Inoxia

Product Information

The physical properties of pure copper in massive form are given in Table 3. Outstanding are the electrical and thermal conductivities which are markedly higher than those of any other base metal and are exceeded only by silver. A copper powder with a purity exceeding 99.95% is available, and, of course, the individual particles have the same properties as massive copper. However, it is impractical to achieve a density of 8.94 g/cm 1 by pressing and sintering alone, and, therefore, the properties of P/M parts are influenced by the density attained. Densification can be increased by additional operations such as double pressing-double sintering or forging, for example, and the properties of the P/M part approach those of the massive metal as a limit. Table 3. Physical Properties of Massive (Fully Dense) Copper P/M friction materials are used as clutches and brakes. Dry applications may include both, but wet applications are normally confined to clutches. For brake and clutch facings, powders having high green strength are essential. Such powders characteristically also have high internal porosity, low apparent density and irregular shapes. Hirschhorn, Introduction to Powder Metallurgy. New York, American Powder Metallurgy Institute, 1969.

As apparent from the above description and as will be shown by the following Examples and Comparative Examples, the method of producing a fine copper powder by the thermal decomposition of anhydrous copper formate according to the present invention can provide a fine copper powder due to the use of the special anhydrous copper formate which has a small primary particle diameter and a low tendency to agglomerate. This particular anhydrous copper formate can be easily produced industrially at a low cost from a cheaper copper compound, and in this case, impurities contained in the starting material can be easily reduced. Powder metallurgy, the technology of utilizing metal powders, offers the engineer a means conserving materials, reducing machining and securing a uniform product at a reasonable cost. This unique metal-forming method permits the production of parts with close tolerances and a minimum of scrap. It also enables the development of products that cannot be produced by any other method. By proper selection of powders, the powder metallurgy (P/M) specialist can control the density of products over a wide range and secure a wide range of mechanical and physical properties. He can produce mixtures of metals that are insoluble in each other or mixtures of metals and nonmetals that combine the properties of both. Anhydrous copper formate produced by any of a variety of methods can be used in the present invention as far as the copper formate to be used satisfies the above requirements. However, anhydrous copper formate prepared by a method using copper carbonate, copper hydroxide or copper oxide as the starting copper compound and reacting this starting copper compound with formic acid or methyl formate is useful as a starting material for the process of the present invention when the process is industrial is performed. While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the scope of the claims.Generally, the major portion of the matrix is copper with about 5-15% low melting metal such as tin; 5-25% lubricant which may be lead, litharge, graphite, or galena; up to 20% friction material such as silica, alumina, magnetite, silicon carbide or aluminum silicide; and up to 10% wear-resistant materials such as cast iron grit or shot. Development of these bearings revolutionized the home appliance industry. By eliminating the requirement of periodic lubrication, the self-lubricating bearing assured many years of trouble-free operation of home appliances and led to a great expansion of the industry. New applications continue to be found and the self-lubricating bronze bearing industry consumes a major portion of the copper powder produced each year. R51/53: Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. In addition, with the exception of anhydrous copper formate, all copper compounds must be heated in a reducing atmosphere (H 2 gas) to form metallic copper powder, and their reactions in the reducing atmosphere are exothermic, their exothermic amounts of heat at least five times greater than that of anhydrous copper formate are.

Therefore, the present invention, which provides a practical and novel process for the industrial production of fine copper powder, is of considerable importance.Density can be controlled to produce parts with porosities as high as 60% or, conversely, those that are practically pore-free and have densities approaching the theoretical density of the metal. It is also possible to vary the density in a single part. And by producing parts with interconnected pores, the metallurgist can obtain a skeleton that can be impregnated with oils, plastics or even a metal having a lower melting point. Using Copper Powders When adding metallic powders to polyester or vinylester resin systems it is important to catalyse the resin prior to adding the metal powder so as to avoid any adverse reaction (rapid oxidisation) of the metal powder by the catalyst. Therefore, the anhydrous copper formate used in the present invention is preferably one having a small amount of these compounds other than copper formate. A practical measure of this is that when a sample of anhydrous copper formate in an amount of 10 mg in a nitrogen or hydrogen gas atmosphere at a heating rate of 3 ° C / min. is heated, 90 weight percent or more of the sample are thermally decomposed within the temperature range of 160 to 200 ° C. It is preferred that the above be considered when the anhydrous copper formate is industrially synthesized for use in this invention. Aluminum bronze P/M parts containing from 5% to 11% aluminum are prepared from blends of the elemental powders. Alloys containing from 5% to 9% aluminum are single-phase materials and have excellent ductility. They can be strengthened by cold working. Alloys containing from 9% to 11% are two-phase materials which are less ductile than the alloys of lower aluminum content. However, they can be heat treated to increase their strengths. kg of a 3 percent aqueous formic acid solution were added to 2 kg of basic copper carbonate (= CUCO 2 Cu (OH) 2,4 H 40 O). The resulting mixture was heated to 80 ° C and kept at that temperature for 30 minutes while the mixture was stirred. The water was then removed by evaporation at 80 ° C under reduced pressure to concentrate and dry the reaction product, whereby 1,28 kg of crystals of anhydrous copper formate were obtained. The thermal decomposition properties of this anhydrous copper formate were tested by adding 10 mg of the anhydrous copper formate in a nitrogen or hydrogen gas atmosphere at a heating rate of 3 ° C / min. were heated. As a result, it was found that the proportion of components which had decomposed in the temperature range of 160 to 200 ° C (hereinafter referred to as "thermal decomposition degree") was practically 100%.