Metal Forming Flashcards
what is bulk deformation?
metal changes shape/dimensions but not volume
what state is the metal in in bulk metal formation?
molten red hot metal
examples of bulk metal formation
- forging
- rolling
- extrusion
describe the extrusion process ?
Extrusion is a bulk forming process in which the work metal is forced or compressed to flow through a die hole to produce a desired cross-sectional shape.
applications of extrusion?
tubes, hollow pipes, frames, doors and window profile
describe forging?
It is a bulk deformation process in which the work piece is compressed between two dies using impact loading to plastically deform it.
advantages of forging
- stronger than machined products
- because of the grain flow products are durable and withstand heavy loads
describe open die forging?
It is a bulk deformation process in which the work piece is compressed between two dies using impact loading to plastically deform it.
describe closed die forging?
It is a bulk deformation process in which the work piece is compressed between two dies using impact loading to plastically deform it.
aplications of open die?
rotors
aplications of closed die?
- knives
- crankshaft
- bolts
- gears
- hand tools
rolling types?
- flat rolling
- shape rolling
- thread rolling
flat rolling?
Flat rolling is a metal forming process in which the thickness of the workpiece is reduced by compressive forces exerted by two rolls rotating in opposite direction. This is usually used to obtain sheet metals at the desired thickness to be used in further operations.
shape rolling?
opposing rolls to change shape of metal
thread rolling?
making screw shapes
shearing?
upper and lower blades used to cut the metal and between them is the clearance they are called the punch and die
how do we determine clearance size?
hard metals require big clearance while soft metals require small clearance
what are plastic and elastic zones?
metal recovers after load in elastic zones but is permanantly deformed in plastic zone
blanking?
Blanking is a cutting process in which a large piece of sheet metal is removed from a larger piece of stock by applying a great enough shearing force. In this process, the piece removed, called the blank, is the desired part.
punching?
is a cutting process in which small material is removed from a piece of sheet metal by applying a great enough shearing force. The product is the sheet metal and the removed part is scrap.
what is the spring back effect in bending and how to mitigate its effect?
after being bent the metal returns back a certain distance because of its spring back component. this can be mitigated by increasing the bending angle
what is a problem with bending?
grain flow must be perpindicular. this is solved by bending at a perpendicular angle to the metal
what are the types of v-bending?
- air bending
- bottoming
circular roller bending?
A sub-operation of bending called Circular Roll Bending where the sheet metal is passed between 3 Rolls to produce a cylinder.
embossing?
