Forging is a process where high compression forces heated metal into desired shapes. The compressed force is applied with the help of a hammer or a press. The process helps to refine the physical properties of the metal along with grain structure of the metal. Using proper design, the metal’s grain can be oriented in the direction of the physical stresses that the metal structure encounters during actual use. Strength, toughness, and ductility are better in a forged metal, with directionally oriented crystals, as compared to the base metal.
The Forging process
Heated metal to be shaped is placed on a mold. Pressure is applied to the metal with the help of a press or hammer and due to this impact the malleable metal conforms to the die cavity shape. Extreme pressure is produced when the die halves are closed. The seam of the die as well as punch acts as a relief valve. Once the metal object is shaped, flashing is removed. Use of a proper lubricant during the process helps to prevent sticking of the workpiece with the die. It also acts as a thermal insulator and helps the wear and tear on the die.
Advantages of Forging
?The forgings are consistent in shape and do not have any voids, porosity, inclusions, or defects. This is especially helpful in later finishing and coating operations as surface preparation is minimized.
?Parts that are produced by this method have high strength to weight ratio and therefore used in the design of the aircraft frames.
?It offers low cost for moderate to long runs.
Different types of Forging processes
?Open Die Forgings or Hand forgings
In this process the forgings are made with the help of repeated blows in an open die. Here the operator manipulates the work piece in the die during the ‘blow’ process, similar to the traditional manufacturing process used by a blacksmith.
?Impression Die Forgings or Precision Forgings
These forgings are the refined form of blocker forgings. The finished metal part much more identical to the die impression.
?Upset Forgings
These forgings increase the cross-section by reducing the length of the metal. The process is used to make heads on valves, bolts and fasteners, and other similar parts.
Other types of forgings are Press forgings, Roll forgings, Swaging, and Net shape forging.
Specifications
The process is used on metals with good ductility such as copper, aluminum, nickel, steel, and magnesium. Minimizing size, material volume, and complexity of the design can reduce cost.
eMachineShop is a custom metal fabrication online shop that allows you to draw and order your own designs. The site provides information about various types of processes and metal fabrication techniques. Visit the site www.emachineshop.com to get information about the products and services and download the firm’s free #D CAD software.
