tailieunhanh - Metal forming

Metal forming to make large parts, take large reductions, use high strength materials, work to net shape (precision flashless closed die forging), and use cold forming to obtain certain physical properties all require high forming forces. These forces may be larger than the capacity of existing machinery.   | METAL FORMING Betzalel Avitzur Lehigh University I. Introduction II. Basic Concepts III. Typical Processes IV. Phenomena V. Replacing Brute Force VI. Approaches to Understanding Metal Forming VII. Summary Glossary Drawing Metal forming process whereby the workpiece is a shaped longitudinal prism that undergoes a reduction and change in its cross section area and shape while being pulled through a shaped converging die. Extrusion Metal forming process whereby the workpiece is placed in a chamber with an opening and is forced to escape through the opening usually being pushed out by a mandrel. Forging Metal forming process whereby the workpiece is placed between an anvil and a hammer and subjected to compressive force between them. Friction Resistance to sliding motion along the interface between two solids. Lubrication Supply of substance on the interface between two sliding solids aimed at reducing the friction and or the wear on the interface. Metal-forming processes Processes that cause changes in the shape of solid metal articles via plastic permanent deformations. Modeling Procedure to present a physical reality by other means. Perfectly plastic materials Idealization of the characteristics of metals undergoing plastic deformations. Pressure-induced ductility Increase in the ability of metals to undergo plastic deformations without fracturing this ability being enhanced by high environmental pressure. Rolling Metal forming process whereby the workpiece is a longitudinal prism which is placed between two opposing circular rolls that rotate in opposite directions drag the workpiece along and force it to reduce in cross section. Simulation procedures Procedures that provide representation of a physical reality through a mathematical or physical model. Metallic components can be shaped in a manner similar to the molding of pottery. The raw material of a fundamental simpler shape is provided by a primary process like casting powder consolidation earlier forming .