metals Flashcards
what are six wasting processes of metals?
-Milling
-Turning
-Flamecutting
-Plasma cutting
-Laser cutting
-Punching and stamping
How does milling work?
-work to be machined is clamped onto table of machine
-can be run in XY or Z direction to cut slots, shaped edges, or thread holes
what are four milling types called
-face milling
-end mills
-fly cutter
-slot cutter
What is turning carried out on?
A centre lathe
How does turning work?
A bar can be held in rotating truck and machines to reduce diameter and to face off end, thread and drill
-material is machined by cutting tools held in tool post- can be moved in and out along bar
What is the two types of turning carried out on?
-CNC lathe
-manually
what does turning using CAD allow
-complex and accurate shapes to be repeated quickly and efficiently
How does flamecutting work?
-it uses Oxy acetylene, gas and flame, cutting torch to deliver intense and focused flame above 3500° C
-It has an additional jet of oxygen to intensify the flame
What’s the disadvantage of flamecutting?
It’s difficult to maintain parallel line with high levels of tolerance
what is the excess material created by flamecutting called?
dros material
what is flamecutting used to cut?
low carbon and alloy steel plate
What is plasma in plasma cutting?
-Superheated, ionised gas that is electrically conductive
How does a plasma cutter work?
plasma cutter will use conductive gas to transfer the energy from the power supply to a conductive material such as a steel plate. It’s heated by plasma to 28,000° C which burns and blows the material away. The cut is fast and clean.
what is laser cutting used for?
Used in industry for precision cutting metals
where does lasercutting get its power from?
Laserbeam thats directed through optics
what does a laser head contain on a laser cutter?
A lens that focuses the laser into a fine beam for cutting and engraving, giving a very fine tolerance of less than 1 mm
What are the advantages and disadvantages of laser cutting?
it’s accurate and uses less energy than plasma cutting. However it can’t cut very thick material. It’s typically used to cut flat sheet material
What is punching and stamping
it uses computer controlled machines that stamps out sections of sheet material by using a sharing action on sheet of metal place between upper tool (punch) and lower tool (die)
what is punching and stamping usually used for?
-Small and medium size production
-And processing metals from 0.5 mm to 6 mm thickness
what are seven types of turning?
-Facing
-Drilling
-knurling
-Taper turning
-parallel turning
-parting
what are five metal forming methods?
-Press forming and spinning
-cupping and deep drawing
-Forging and deep forging
-Casting
what is a stock form and products produced in press forming?
SF: sheet
Products: metal sheets, car body panels, and boxes
what are key features of press forming?
-shapes sheet metal into 3-D forms
-often uses robotics for lifting sheets
-Mass/large scale batch production
What is the stock form used for spinning and the products it produces?
SF: sheet
Products : Body of kettle, saucepans, and metal light shades
Key features of spinning
-Product may show parallel lines, where sheet has been forced onto mandrel
-Mass/small batch production
what is the stock form and products produced using cupping and deep drawing?
SF: sheet
Product : tube like shapes, like fire, extinguisher and drinks cans
what are key features of cupping and deep drawing?
-Starts with metal blank
-Metal is stretched into shape
-High initial tooling cost
-Large scale mass/continuous production
what is a stock form and products produced using drop forging?
SF: billet
Product : spanners and pliers
what are key features of drop forging?
-used for products that need to be tough/hard
-Maintains internal grain structure, which retains strength
-Hot metal billet shaped on anvil/die then pressed into shape and cooled
-Suitable for mass production
what is the stock form and product produced using wrought iron forging?
sf: bar
Products : decorative metal work like gate scrolls and fencing
what are key features of wrought iron forging
-uses wrought iron which has a carbon content of 0.08%
-Hand/hydraulic press
-One off/small batch production
bending stock form and products produced?
sf: sheet/plate
Product : seams on metal edges
Key features of bending
-Doesn’t include punching/trimming of metal
-Can be carried out in school workshop
-Large scale batch in industry
stock form and products of rolling?
sf: billet
Product : hot rolling- angle bar, beam railway tracks
Cold rolling -filing cabinets, chairs and drums
what are key features of rolling?
-hot rolling results in uniform, mechanical properties, with no deformation or stresses
-surface coated with carbon deposits, which must be removed using acid pickling
-Cold, rolling results in a material that has hire tolerance and better surface finish
What is a stock form and products produced using sandcasting?
sf: molten metal from billet
Products : railway carriage, wheels, vices, and postboxes
what are key features of sandcasting?
-Labour intensive process
-Not a high-quality surface finish
-Suitable for one off/small batch production
stock form and products produced using gravity diecasting
sf: molten metal from billet
products: Alloy wheels, engine components and doorhandles
Key features of gravity diecasting?
-Low melting point, metals like aluminium and zinc based alloys are used
-Relies on gravity to help metal flow into mould
-Used for thicker mould sections
-Large batch/mass production
stock forms and products produced using pressure diecasting
sf: molten metal from billet
products: toy cars, collectible figures and door handles
Key features of pressure diecasting
-Intricate detail designs
-Low, melting point metal such as aluminium and zinc based alloys
-molten metal stored in a chamber, then shot of molten metal is forced into die
-fast process
-Large batch/mass production
what is a key feature Of a pressure diecasting in a cold chamber
-Molten metal labelled into shot chamber, and hydraulically pushed into chamber
what is stock forms and products produced in investment casting
sf: molten metal from billet
Product : cast jewelry, hip replacement joints
Key features of investment casting?
-used for intricate/awkward shapes that would be difficult/ impossible to mould using any other casting process
-High-quality excellent finish
-Wax patterns are cast from master mould
-Repeatable and high-quality
what are the 7 joining methods of metals
-riveting
-brazing
-hard + soft soldering
-oxy-acetylene
-spot welding
-MIG welding
-TIG welding
what does MIG welding stand for
metal inert gas
what does TIG stand for
tungsten inert gas
what’s MIG welding used to weld
-thin gauge metals like aluminium and steel
how does MIG welding work
-wire electrode melts in ark and fills gap between metals
-Welding torch is gently swelled to form a bead of weld
-The electrode wire is stored on a real and is fed
-Inert gas shield the area being joined to prevent oxidisation in the weld
What type of of production is MIG welding used for?
one off
What type of inert gas is used in MIG welding?
CO2 or argon
What does MIG welding use?
a consumable wire electrode
what is MIG welding Used to make?
Bike frames and climbing frames
what is TIG welding Used to weld
-Stainless steel and aluminium and copper alloys
how does TIG welding differ from MIG welding?
it’s an electric arc welding process but electrode made out of tungsten doesn’t melt in the process of filler is added separately
what does TIG welding gas shield use?
-Argon or helium
what does TIG welding give greater control of?
Where the world is going, meaning increased accuracy, so the joint will be stronger
What products does TIG welding used to make?
Stainless steel ladders for boats
what is spot welding used to weld?
Mild steel sheet metals at the point along in length without using a filler
