Cold extrusion of the metal zinc stearate main description of the processing

Cold extrusion is a precision plastic volumetric forming technology is an important component. Cold extrusion is in the cold state of the metal blank into the mold cavity, the strong pressure and a constant speed under the effect of forcing the metal is extruded from the magnesium hydroxide flame retardant  mold cavity, to achieve the desired shape and size, and a certain mechanical extrusion performance.
Currently, cold extrusion technology has been in fasteners, machinery, instruments, electrical appliances, light industry, aerospace, marine, military, and other industrial sectors widely used. Specific products such as filter, electric fuel pump housings, capacitor housings, aluminum bottle, cosmetic aluminum tube, the bullet casing, at present, auto parts, 30% ~ 40% of the parts are manufactured by cold extrusion process.
Currently available for cold extrusion of metal materials: lead, tin, silver, aluminum, aluminum alloy, copper and oxygen-free copper (T1, T2,, brass, bronze, nickel, zinc and cadmium zinc alloys, pure iron, carbon steel, low alloy steel and stainless steel. Additionally, some for titanium and titanium alloys, tantalum, zirconium, and Kovar, etc. can also be cold extrusion, even bearing steel GCr9, GCr15 and HSS W6Mo5Cr4V2 also be a certain amount of cold extrusion deformation.
Cold extrusion, metal materials produced  red iron oxide severe plastic deformation, the unit squeeze a lot of pressure, especially in cold extrusion of steel, the largest unit extrusion pressure up 2500Mpa. In such a high unit pressure, if no good lubrication, steel particles will be bad material welded together with the mold cavity which led to severe scratching the surface, making the extrusion pressure increased dramatically, mold life greatly decreased, even rupture . Lubrication is directly related to product quality and tool life, determines the success or failure squeeze.
So the use of a good and reliable lubrication of cold extrusion method is very important. Currently used for a liquid lubricant (such as animal oils, vegetable oils, mineral oil, etc.), there are solid (such as zinc stearate, sodium stearate, graphite, etc.), they may be used  black iron oxide alone, or in combination.
Lubricant mainly in: 1. Reduce friction between the billet and the mold; 2. Reduce mold wear and improve die life; 3. Improve the quality of products. (1) cold forging lubricant: For forging, the more successful lubrication of the current approach is to phosphating metal blank surface saponification treatment. The so-called "phosphate" is chemically formed on the surface of the metal material of iron phosphate, zinc phosphate and the porous film. The film thickness is generally 10-25μm, the friction coefficient is low. Phosphate film is firmly bonded to the surface the metal billet with a certain plasticity, to some extent deformed together with the metal, this layer of porous membrane capable of storing a lubricant, when squeezed, can play the blank isolated from the mold effect and reduce the deformation friction between the metal and the mold. The so-called "saponification" is a fatty acid soap as a lubricant, so that the zinc phosphate coating with a chemical reaction treatment of zinc stearate lubricant.
Because phosphate - saponification treatment processes numerous long processing time, phosphate strict quality requirements, while the phosphate waste pollute the environment, and thus the world are seeking new ways to replace phosphate lubrication - saponification process.
Aqueous zinc stearate as a lubricant with good extrudability, extension, adhesion, lubricity
Its safety non-toxic environment pollutant emissions, successfully replaced phosphate - saponification treatment process (degreasing rust - water cleaning - acid - water cleaning - phosphate - water cleaning - drying - saponification - - dried), ferrous metal cold forming to meet the demanding requirements for lubrication. And once completed: Surface treatment - water heating - dipping the agent - drying and other processes. For extension of large, high deformation, surface complex parts processing production, product processing effectively guarantee the accuracy, improve surface quality, maximum protection of the mold surface, to extend the life of the mold. A thin lubricant film formed, one-piece lubricant low cost, cost than phosphate - saponification cost savings of 30% to 45%.
Water-based stearate lubricant characteristics
Brushing the surface of the workpiece after forming a lubricating film polymer, even if subjected to repeated cold work extrusion, cold stamping, cold drawing forming, the lubricating film can be firmly attached to the workpiece surface, and with the extension of the surface extension without brushing again. Especially when applied to extension degree, deformation rate, complex workpiece surface, which is characterized more apparent.