Bulk forming processes
other terms closed-die, high energy rate, hot upset, open-die, powder, precision, radial, heading.
definition The process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses and related forming equipment. Forging hammers, counterblow equipment and high energy rate forging machines apply impact to the workpiece, while most other types of forging equipment apply squeeze pressure in shaping the stock. Some metals can be forged at room temperature but most have their yield stress reduced by heating. Below the recystallisation temperature a material is warm forged, above this temperature the material is said to be hot worked.
other terms direct (forward), indirect (backward), impact, hydrostatic
definition The conversion of an ingot or billet into lengths of uniform cross section by forcing metal to flow plastically through a die orifice. In forward (direct) extrusion, the die and ram are at opposite ends of the extrusion stock, and the product and ram travel in the same direction. Also, there is relative motion between the extrusion stock and the die. In backward (indirect) extrusion, the die is at the ram end of the stock and the product travels in the direction opposite that of the ram, either around the ram(as in the impact extrusion of cylinders such as cases for dry cell batteries) or up through the centre of a hollow ram.
other terms rod, wire, tube (not to be confused with deep drawing – see sheet processes)
definition A term used for forming operations such as drawing rod, wire and tube.
other terms fluid forming
definition Similar to sheet hydroforming but used on tubular materials