Processes for Forging of Metals Dec16

Processes for Forging of Metals...

Processes for Forging of Metals Metal forging is a deformation process where metal is pressed, pounded or squeezed under great pressure into high strength parts known as metal forgings. The forging process is entirely different from the casting (or foundry) process, as metal used to make forged parts is neither melted nor poured as in the casting process. Forging is defined as a metal working process in which the specific shape of metal work piece is obtained in solid state by compressive forces applied through the use of dies and tools. During the forging process controlled deformation of metal takes place. Forging process is accomplished by hammering or pressing the metal.  In modern times, industrial forging is done either with presses or with hammers powered by compressed air, electricity, hydraulics or steam. All the metals and alloys are forgeable, but the forgeability rating of different metals and alloys can vary from high to low or poor. The factors involved are the composition, crystal structure and mechanical properties all considered within a temperature range. The wider the temperature range, the higher the forgeability rating. Most forging is done on heated work pieces. Cold forging can also take place at the room temperatures. Forging process is one of the oldest known metalworking processes with its origin about some thousands of years back. The process goes back to 8000 BCE and evolved from the manual art of simple blacksmithing. Traditionally, forging was performed by a smith using hammer and anvil. Using hammer and anvil is a crude form of forging. The smithy or forge has evolved over centuries. Then as now, a series of compressive hammer blows performs the shaping or forging of the part. Modern forging uses machine driven impact hammers or presses which deform the...

Metal Forming Processes...

Metal Forming Processes Metal forming processes consists of deformation processes in which a metal work piece (billet, bloom, or blank) is shaped by tools or dies. The design and control of such processes depend on the characteristics of the material of the work piece, the requirements of the finished product, the conditions at the interface of the tool and the work piece, the mechanics of plastic deformation (metal flow), and the equipment used. These factors influence the selection of geometry and material of the tool as well as processing conditions (examples are temperatures of die and work piece and lubrication). Since many of the metalworking operations are rather complex, models of various types, such as analytical, physical, or numerical models, are often used to design these processes. A brief historical view, a classification of metalworking processes and equipment, and a summary of some of the more recent developments in the field are described below. Historical view Metalworking technology is one of three major technologies used for the fabrication of the metal products. The other two are casting process and powder metallurgy (P/M) technology. It is possibly the oldest and most established of the three technologies. The earliest records of metalworking show that the simple hammering of gold (Au) and copper (Cu) was practiced in various regions of the Middle East around 8000 BCE. The forming of these metals was crude since the skill of refining by smelting was not known and since the ability to work the material was limited by impurities that remained after the metal had been separated from its ore. With the start of Cu smelting around 4000 BCE, a useful method became available for purifying metals through chemical reactions in the liquid state. Later, in the Cu age, it was...