Metal Working Process Flashcards
are those formed by physically working the
metal into shape
Wrought objects
are formed by pouring molten metal into
molds.
cast items
When it comes to mechanically working
metal into a desired shape, there are three
methods commonly used.
They are hot-working, cold-working, and extruding
the process of forming metal at an elevated temperature when it is in its annealed, or soft condition
Hot-working Process
consists of forming hot metal ingots with rollers to form sheets, bars, and beams
Rolling
is a process wherein a piece of metal is worked
at temperatures above its critical range.
Forging
is a process of reduction of the
cross-sectional area or shaping a metal
piece through the deformation caused by a
pair of rotating in opposite directions metal
rolls.
Rolling
– 6x6 .in or larger; approximately square
Bloom
– less than 6x6 in; approximately square
Billet
– rectangular sections in which the width is greater than twice the thickness
Slabs
is forming a preheated workpiece by
using impact energy of the falling
hammer forcing the metal to fill
the space between the punch (a part
attached to the hammer) and
the forging die (a part attached to the
anvil).
Hammer forging (drop forging)
The surplus metal which has been
squeezed out into the relieved section
is called _________.
the fin or flash
is used to form large and heavy parts. Since a press is slow acting, its force is uniformly
transmitted to the center of the material being pressed.
Pressing
is a hammering process whereby a hot ingot is placed between a pair of formed dies
in a machine called a drop hammer and a weight of several tonsis dropped on the upper die
Drop forging
is a type of forging that is usually used on small parts because it requires a metalworker to physically hammer a piece of metal into its finished shape.
Hammering (smith forging)
is a forging operation which is employed for manufacturing head of bolts, valves,
artillery shells and other parts where increase of cross section dimensions of the workpiece is
desired.
Upset forging
is a forging operation involving reduction of the workpiece diameter (with increase of its length) by rolling it between two grooved rolls rotating at the same rotating direction.
Roll forging (Swaging)
performed well below a metal’s critical temperature and ranges from the manual bending of sheet metal for skin repairs to drawing seamless tubing and wire.
Cold-working
usually refers to the rolling of metal at room temperature to its approximate size. Once this is done, the metal is pickled to remove any scale, and then passed through chilled finishing rolls.
Cold-rolling
is used in making seamless
tubing, wire, streamlined tie rods, and other
forms of stock
Cold-drawing
the process of forcing
metal through a die which imparts
a required cross-section to the
metal.
Extrusion
The principal advantage of
the extrusion process is its ________
flexibility
are being more generally used in aircraft construction as a result of improved quality and the development of high-strength heat treatment.
Casting
– consists of the manufacture of pattern, pouring the metal into the mold, and the removal and finishing of the casting after it has solidified in the mold.
Static Casting
– devised as a method for applying pressure to the molten metal during the casting operation. Pressure is obtained by whirling the mold.
Centrifugal Casting
– only an external mold is used and is spun around its own axis
True centrifugal
– an inside core is used as well as external mold
Semi-centrifugal
– work is rotated around an independent central axis about which the molds are grouped radially.
Centrifuge
– “lost wax” process of casting is used for intricate parts that must be held to high accuracy in size and shape at a reasonable cost
Precision Casting
is composed of two or more metal elements mixed together
An alloy
