MP1, MP2, and MP3

Manufacturing Processes Quiz 3

Atomic Bonds

Microscopic forces between atoms that determine material strength

Crystalline Lattice

Ordered atomic arrangement affecting various material properties

Elastic Deformation

Temporary change in shape that reverses when force is removed

Plastic Deformation

Permanent change in shape that remains after force is removed

structure; processing

Metalworking shifted from trial and error to an engineering mindset where ________ + ________ determine properties, and properties determine performance

low; hardness

cold working is shaping metal at ___ temperatures to increase ________

plastic; solid

metal forming shapes metals by _______ deformation, and the material remains in the _____ state

high forces required, expensive

what is a limitation of metal forming?

deformation processes

bulk flow, simple shearing, simple or compound bending

tension, compression, shear

stresses

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label image

rolling, forging, extrusion, deep drawing, wire and tube drawing, stretching and bending

examples of forming processes

lubrication, tool or die geometry, starting temperature, starting geometry

independent (controlled by an engineer)

surface finish, force/power requirement

dependent (results of process)

experience (trial and error), experimentation (lab testing), process modeling

list the three methods given for understanding independent dependent relationships

1990s

finite element modeling (FEM) became practical with desktop computing power in the ____

contact pressure (P) on x-axis, friction (F) on y-axis

fill in axes of a sloped line

contact pressure

at low loads, friction is proportional to _______________ (coulomb coefficient mu)

> 0.6

hot working is plastic deformation above the recrystallization temperature. this is typically ____ x melting temperature (absolute scale)

< 0.3

cold working is plastic deformation below recrystallization temperature. usually at room temperature ( ____ x melting temperature)

1.8 billion

global steel production alone exceeds ___________ tons annually

oxidation and scaling at high temperatures

what is a limitation of hot working?

better reproductibility and interchageability

what is an advantage of cold working?

scale; unit

however there is no recognized _____ or ____ describing formability

asia - pacific (china, japan, india)

dominated high-volume bulk deformation (rolling/forging) and raw material processing

north america and europe (usa, germany)

focus on high-precision forming, aerospace alloys, and automated sheet metal stamping

rolling, forging, extrusion

list 3 examples of bulk deformation processes

billet is smaller and has a circular cross section

what is the difference between a bloom and a billet?

decrease; increase

rolling typically results in a _______ in thickness and ________ in length

lower cost and higher rates of production

what is the benefit of thermomechanical processing?

open-die hammer forging

which type of forging was used by blacksmiths?

mechanical; hydraulic

what are the two types of forging presses?

disk-shaped; conical

which type of products is orbital forging used to form?

upset

which type of forging is the most widely used when evaluated in terms of the numbers of pieces produced?

low cost, high production speed, minimum labor

what are three reasons why automatic hot forging is so attractive to manufacturers?

precision

forging operations that produce parts that require little to no machining afterwards in order to reduce cost and waste are called

billet; shaped die

extrusion is a metal forming process in which a _____ is forced to flow plastically through a ________

uniform

extrusion primarily produces parts with a ______ cross-section along their length

direct; indirect

in ______ extrusion, the billet moves relative to the container, while in _______ extrusion the billet remains stationary

pulled

drawing is a deformation process in which metal is ______ through a die to reduce its cross-section

compressive

wire, rod, and tube drawing are dominated primarily by _________ stresses

restores ductility

why is intermediate annealing used during drawing operations?

room

cold forming processes are performed at or near _____ temperature

excellent surface finish; tight dimensional tolerances

list two advantages of cold forming

plastic; material

piercing produces holes by ______ deformation with little or no _______ removal

squeezing

coining, heading, and sizing are examples of ________ processes

cutting; formation of chips; burning; melting

shearing is the mechanical ________ of materials without the ___________ or the use of ________ or ________

the lower shearing blade

what is a die?

piercing → punched piece is scrap and rest is desired

blanking → punched piece is desired and the rest is scrap

what is the difference between piercing and blanking

decreases the max force needed to shear metal

what is the purpose of the rake angle in shearing

linear; independent

true bending with multiple bends has axes that are ______ and ________ of each other

small amount of unbending in metal due to elastic deformation

what is springback?

determine the minimum bend radius; account for any possible springback; account for previous work to material; determine dimensions of flat blank

list 4 considerations that should be made before bending a workpiece

any bending material

what kind of materials can be roll-formed?

increases; decreases

the stretching process _________ surface area and ___________ thickness

spinning

manufacturing process shown

blank; punch

the draw ratio is the ratio between the _____ diameter and the ______ diameter

shallow cup (likelihood of tearing/wrinkling is low); hold-down pressure is important

what are two risks associated with a think blank thickness and increased cup depth?

long cycle times; high cost of tooling and process setup

what are two disadvantages of tube hydroforming?

austenite

during hot stamping, what kind of microstructure is created when the blank is heated

thins the walls

why is ironing used after deep drawn process?

manual; mechanical; hydraulic; servo

what are four classifications of presses

multiple simultaneous

transfer presses have a long slide that enables ______ __________ operations