Cold extrusion

PROCESS MATERIAL. IMPACT EXTRUSION COLD FORMING COLD EXTRUSION SHEET METALWORK MACHINING POWDER METAL SINTERING... 

Hot extrusion - Aluminium and magnesium alloys Extrusion - Tliermoplasties Extrusion - Elastomers Cold extrusion... 

A technological variation that permits a continuous process is the polymer extrusion through a spinneret of the desired design allowing crystallization inside the spinneret26. In this way, the cold extrusion stage used in Porter s method can be avoided. The degree... 

The extrusion process requires the use of a lubricant to prevent adhesion of the aluminum to the die and ingot container walls. In hot extrusion, limited amounts of lubricant are applied to the ram and die face or to the billet ends. For cold extrusion, the container walls, billet surfaces, and die orifice must be lubricated with a thin film of viscous or solid lubricant. The lubricant most commonly used in extrusion is graphite in an oil or water base. A less common technique, spraying liquid nitrogen on the billet prior to extrusion, is also used. The nitrogen vaporizes during the extrusion process and acts as a lubricant. 

Extruders are normally classified by their method of construction, i.e. twin screw or single screw and the operating conditions, i.e. cold extrusion or extrusion cooking. Cold extrusion is used to make liquorice and pasta among other products and so is outside the scope of this work. Extrusion cooking, which is defined as heating the product above 100 °C, has many uses. 

Keleb El, Vermeire A, Vervaet C, et al. Cold extrusion as a continuous single-step granulation and tableting process. Eur J Pharm Biopharm 2001 52 359-68. 

Note As the metal in current cast steel or cold extrusion shells is less porous than heretofore, there is a tendency to eliminate base covers, especially in smaller caliber shells(Ref 4)... 

Cold Extrusion of Metals. See under Cold Working or Shaping of Metals... 

In the cold extrusion process a piece of metal (such as steel) is forced to flow, at room temperature, under high, rapidly applied pressure, thru an orifice of the die. This produces a tubular object of the desired size... 

Application of cold extrusion process to manuf of artillery shells is discussed in Refs 8, 9. 10. 12, 13 14 and its application to manuf of gun-barrels is briefly discussed as the Auto-frettage or Self-hooping in Vol 1, p A510-R of this Encycl... 

Descriptiorf of Ger cold extrusion process) 2)Heinz Co Reports on cold... 

Cold shaping of steel by compression reaches commercial application) 5)H.J.Pessl 8c H.H.Hautmann, Iron Age, 1953 (August), 69-73 (Factors influencing cold extrusion of steel) 6)T.Bishop, Iron Age 1953 (August), 74 7 (Tools lubricants and steels for cold extrusion) 7)J. G.Henderson 8c J.M.Bates, "Metallurgical Dictionary", Reinhold, NY (1953), 77-8 8)W.C. Tucker, Ordn 38, 458 (1953) (Examples of ammunition articles manufd at present by the cold extrusion process) 9)Battelle Memorial Institute, "Shaping of Steel by Extrusion Method", Frank-ford Arsenal, Philadelphia, Pa, 31. July, 1954... 

I960) (Cold forging known as "Swaging process") 14W.deVore, Ordn 48, 316-24 (1963) (A German method of cold extrusion as improved and expanded by the Kelsey Hayes Co, Romulus, Mich, so that artillery shells of large caliber can be mass produced quickly and economically)... 

Keleb, E.I., El Keleb, Vermeire, A., Vervaet, C., and Remon, J.P Cold extrusion as a single-step granulation and tabletting proceSsur. J. Pharm. Biopharm., 52 (2001), 359-368. 

G.E.Whitlock, Ordn 38, 694-96 (1954) (Cold extrusion process by the method developed in 1947 by Whitlock at the Liberty Plant of the Mullins Manufacturing Corp, Salem, Ohio)... 

Hot or cold extrusion Paste, bonded film Heat, high loads... 

Since commercial dispersions and bonded coatings became widely available, the use of powder-burnishing has probably declined, but applications to ball-bearings have been reported " , and a 1981 report described a cold-extrusion machine for steel components in which a burnished film of molybdenum disulphide was applied to the steel billets automatically prior to extrusion . This resulted in a reduction in extrusion loads and improved quality. 

New MoSj Coating Process Cuts Cold Extrusion Costs at Braun Engineering, AMAX Molysulfide Newsletter, 23, 2, (1981). 

Cold shaping of steel by compression reaches commercial application) 5)H.J.Pessl H.H.Haucmann, Iron Age, 1953 (August), 69-73 (Factors influencing cold extrusion of steel)... 

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