Exam metal processes Flashcards
types of stamping or pressing
piercing
blanking
notching
croppig
hending
forming
what piecing
where suitable punch shears a whoole in piece of metal
what is blaking
where punch shears the required shape from metla
what is cropping
where pucnh shears a plain or shaped length
what is bedning
where shit bent
what formig
where metal ks forced into the shape of the surface contous of a die
hwo press formign etc etc work
hydralich press just stamps whoels into shit
or forces into a shape
or forces around a jig, which bends it
formign step by step
sheet prepped
sheet stamped, formed , with hydralich press
how bendign work
aroudna die
when a sheet has a whoel or shape in it what is it called
piecing
when a sheet has a hole or bit fo metal taken out what is it called
blanking
what are majroity fo press related oepartings confiend to
large batch production
why majority fo press related shit left to large batch prod
high costs
length tool settign up involbed
what can be used to maxamsisie and economies press formign
cnc to work out best nesting of shapes etc
types of preses
arbor press
fly press
what is arbor pressing
hand operated shit
what is fly press
heavy iron frame
square ram
big release
boom
pros of balankign and peircing
many sahpes
any metal
high accuracy
cons fo blankign and peircing
restrcite to metal sheets
limited to size of stcok meteriasl
can be high waste
what press forming (booklet)
sheet metals loaded into press
clamped togheter
inblank holder
pucnh forces metal throguh die to take shape of punch
pros of pres formign (bookelt)
3d shapes
icn stiffness
carried otu at room temo
high to med vol
seamless sheets in one go
cons of press formign (booklet)
high tooling costs
high levels of force needed
what sand castin
low cost method of castign emtal in sand mould
s
scale of sand cast
one off or low volume production
step by step of sand castin
pattern palced in box
box filled with sand
sand solidifies
sprue channels are made
pattern rremoved
top mould half doen same process
moulds put on top of eahcother, lcoator pins for alignment
molten metalin
finish
what to ensure there is on sand cast diargam
vents
sprue channels
parting pwoder between the moulds
slightly larger pattern than required
adv of sand castign
low cost
easy to opertate
intircate parts
flexibel levels of production
cons fo sand casting
moudl remade for every part
overall accuracy is poor
parts need finising
is high pressure diecastign economical
yes
how die castign work
molten metal poured into champer
piston or plunger forces metal at high pressure into caviy
pressure kept utnilshti solidifies
inejctor pins push out compoenents
what die castign diragam look lie
inj mould
put instead of scre its plunger that pushs metal into die
pros of die castign
re use moulds
no finsihign really
accurate
fast
small thin parts
cons of die castign
expensive
can have weak strcutrue in parts
can nneed soem extra finsiing
why steels and ferrous metals nto used in die castign
need high temp to metl them , whcih can damage moudls and accuracy leveels
what gravity die castign
permanent metl die
metal poured in
let gravty do its thing
why pressure die castign give better quality than gravity
presssure contstantl pushign emanign good contact with the die costantl
what to make sure on die cast drawing
soem form fo coolign system
what millign
removal of material using mutli tooth cuttign shit
work piece is secured to the bachine and then fed udner the cutter
what moves on milling machien
the bed
what millign allow for
rapid removal fo material
slots
steps
what plasma cuttign
stream of ionisied gase which ebcomes so hot it vaporises metal cut
materials used in palsma cutting
any electrically conductive etal
commonely stainelss steel or alimiunm
pros of plasma cutting
good for small natches
clean cuts
cons of palsma cutting
nto good for thin metals
very enegery intesive
high wastage when hand hel
how sinterign work
material curshed to pwoeder
powder comapcted in die
compacted shape then heated
partciles bond
brazign step by step
metal cleaned
flux brushed along joint to prevent oxidisation
pressures gas fed through nozzle and lighted
joint heated with flame until piping
rod pushed aginst until melted
addv of brazing
low cost
not effect that host mateiral really
strong bond
no need for 2ndary finishig
complex and itnricate joitns achieved
shit can eb dismantled and rejoine d
all scales of production
cons of brazing
cna be time consuming
maetriasl sued in brazing
copper
steel
silver rod
how tig welding work
tig generates heat via an arc of electicity jumping from tunsgtene metal electrode to metal you intned to world
heat melts edges
flux is used
adv of tig welding
uses electric current
reduces sparks and shit
less contamination
no toolign costs
dis adv fo tig
high set up tiem
skilled process
expensive
complex
