Mechanical Deformation of Metals
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TAFE NSW -Technical and Further Education Commission www.highered.tafensw.e du.au ENMAT101A Engineering Materials and Processes Associate Degree of Applied Engineering (Renewable Energy Technologies) Lecture 7 – Mechanical shaping of metals
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ENMAT101A Engineering Materials and Processes Associate Degree of Applied Engineering (Renewable Energy Technologies) Lecture 7 – Mechanical shaping of metals. Mechanical Deformation of Metals. EMMAT101A Engineering Materials and Processes. Ashby: Fig 13.2 The classes of processes. - PowerPoint PPT Presentation
Transcript of Mechanical Deformation of Metals
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ENMAT101A Engineering Materials and ProcessesAssociate Degree of Applied Engineering (Renewable Energy Technologies)Lecture 7 – Mechanical shaping of metals
TAFE NSW -Technical and Further Education Commission
Mechanical Deformation of Metals
EMMAT101A Engineering Materials and Processes
Reference Text Section
Higgins RA & Bolton, 2010. Materials for Engineers and Technicians, 5th ed, Butterworth Heinemann
Ch 7
Additional Readings Section
Sheedy, P. A, 1994. Materials : Their properties, testing and selection Ch 13
Callister, W. Jr. and Rethwisch, D., 2010, Materials Science and Engineering: An Introduction, 8th Ed, Wiley, New York.
N.A.
Ashby, M.F., 2011. Materials Selection in Mechanical Design, 4th Ed, Butterworth Heinemann, Oxford, UK.
Ch 13
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EMMAT101A Engineering Materials and Processes
Ashby: Fig 13.2The classes of processes
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Hot-working processes (Higgins 7.2)
EMMAT101A Engineering Materials and Processes
Hot Working processes are carried out above the recrystallisation temperature of the material.
7.2 Hot Working Processes7.2.1 Forging7.2.2 Hot-rolling
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Hot-working processes: Forging (Higgins 7.2.1)
EMMAT101A Engineering Materials and Processes
VIDEO: Open-die forging can produce forgings from a kg to more than 150 tonnes. “Open-die” means the metal is not confined laterally during forging. The process works progressively from the starting stock into the desired shape. Flat-faced dies are usual.Wide range of shapes and sizes are possible, especially suited to large custom parts like a ship’s propeller shaft.
Seamless Rolled Ring Forging: Starts with a cast billet, then upset and punched to form a donut shape, then rolling and squeezing (or in some cases, pounding) the donut into a thin ring. Ring diameters can be anywhere from a 100mm to 10m.
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Hot-working processes: Hot-Rolling (Higgins 7.2.2)
EMMAT101A Engineering Materials and Processes
Cobble: http://www.youtube.com/watch?v=NnqZ-ybpdhQCobble 2: http://www.youtube.com/watch?v=v4p-YCtbhMQ
Hot Rolling (Billet to plate/sheet): Dalarna University www.du.se(Creative Commons)Breaking down billets (large thick slabs cast from the furnace) into successively thinner plate, and finally sheet.
HD-720Fun and Games with Hot Rolling…“Cobble” = British terminology“Miss-roll = US terminology
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Hot-working processes: Extrusion (Higgins 7.2.3)
EMMAT101A Engineering Materials and Processes
Like squeezing toothpaste from a tube, material is forced through a die and is plastically deformed into the cross-section of the die. The die hole can be almost any shape, (e.g. a circular die will make a rod)
openlearn.open.ac.uk
Mostly used for low temperature metals: copper pipes, aluminium extrusions.Steel can only be drawn or hot rolled, but not extruded in the same way as aluminium.Pity. Would have been a nice way to make steel pipe.
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Hot-working processes: Extrusion (Higgins 7.2.3)
EMMAT101A Engineering Materials and Processes
Extruding a hollow shape is an obvious problem. How do you hold the die that forms the hole?
http://openlearn.open.ac.uk/mod/oucontent/view.php?id=399740§ion=3.5
Extrusion bridge die making a hollow section product. Note: in reality, the die and ring are held together.
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Hot-working processes: Extrusion (Higgins 7.2.3)
EMMAT101A Engineering Materials and Processes
Heated to about 900oF (480oC) to keep it well above the recrystallisation temperature (150oC).
The design of the extrusion profile effects extrusion performance. (E.g. Better to have symmetry, avoid long flats, minimize internal holes, etc…) PBCLinear
Aluminium dominates the extrusion industry because the metal has excellent ductility without the need for extreme temperatures. It is also an obvious choice for window frames, structural and decorative parts, and almost anything of a constant cross-section.
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Hot-working processes 3 (Higgins 7.2)
EMMAT101A Engineering Materials and Processes
Other Hot Working Processes
Hot forming of Coil Springs:http://www.youtube.com/watch?v=6BplSiK8qK8
Friction Welding: http://www.youtube.com/watch?v=5JbnDXw-0pM
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Cold-working processes (Higgins 7.3)
EMMAT101A Engineering Materials and Processes
Cold Working processes are carried out below the recrystallisation temperature of the material.
See text:7.3 Cold Working Processes7.3.1 Cold-rolling7.3.2 Drawing7.3.3 Cold-pressing and deep-drawingBolts: http://www.youtube.com/watch?v=7PQyant3mCc
7.3.4 Spinning7.3.5 Stretch-forming7.3.6 Coining and embossing7.3.7 Impact-extrusion
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Cold-working processes: Cold Rolling (Higgins 7.3.1)
EMMAT101A Engineering Materials and Processes
Cold Rolling Steel Sheet: Steelmaking: Cold Rolling by CorusBCSATraining
Roll Curving Steel plate for Wind Turbine Towerhttp://www.tsgnorthamerica.com
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Cold-working processes: Drawing (Higgins 7.3.2)
EMMAT101A Engineering Materials and Processes
Cold Drawing of Hexagonal Bar http://www.youtube.com/watch?v=72JWZAWZp5Q
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Cold-working processes: Cold Pressing and Deep Drawing (Higgins 7.3.3)
EMMAT101A Engineering Materials and Processes
Forming Boltshttp://www.youtube.com/watch?v=7PQyant3mCc
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Cold-working processes: Spinning (Higgins 7.3.4)
EMMAT101A Engineering Materials and Processes
Metal Spinninghttp://www.youtube.com/watch?v=7PQyant3mCc
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Cold-working processes: Stretch-forming (Higgins 7.3.5)
EMMAT101A Engineering Materials and Processes
Stretch Forminghttp://www.youtube.com/watch?v=eSVi7dC5L_Q
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Cold-working processes: Coining and embossing (Higgins 7.3.6)
EMMAT101A Engineering Materials and Processes
Stampinghttp://www.youtube.com/watch?v=I7uBmlwxXRU
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Cold-working processes: Impact Extrusion (Higgins 7.3.7)
EMMAT101A Engineering Materials and Processes
Impact Extrusionhttp://www.youtube.com/watch?v=zMhVPId-pRA
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Cold-working processes: Roll Forming
EMMAT101A Engineering Materials and Processes
Roll Forming – Roofinghttp://www.youtube.com/watch?v=HrDegG_zkWY
Spiral Ductinghttp://www.youtube.com/watch?v=fIe8PQXNrUo
ERW Pipe Forming (5” or 125mm)http://www.youtube.com/watch?v=77utCIwKSn4
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Powder Metallurgy (Higgins 7.4)
EMMAT101A Engineering Materials and Processes
Powder Metallurgy (PM) involves pressing the powder and then heating (above recrystallisation but below the melting point) – called sintering – which binds the particles together.
See text:7.4.1 Uses of powder-metallurgy7.4.2 Cemented carbides7.4.3 Sintered-bronze bearings
Powder Metallurgyhttp://www.youtube.com/watch?v=_0wd8sgNIOg
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Machining metals (Higgins 7.5)
EMMAT101A Engineering Materials and Processes
Machining is a cold-working process in which the cutting edge of a tool forms shavings or chips of the material being cut.
See text: Higgins 7.5
Machining a large shaft – Lathehttp://www.youtube.com/watch?v=ObsvfP5Nrw4
High Speed Video: Milling Cutterhttp://www.youtube.com/watch?v=IUBQN1JfY80
Machining Centre: 5 axis various jobshttp://www.youtube.com/watch?v=0LCaRqQ8Qf8
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Profile Cutting
EMMAT101A Engineering Materials and Processes
This is for cutting sheet material. Usually CNC• Laser. Fast, accurate, good finish, many materials. Finest kerf. Fussy
maintenance.
• Water jet: Almost any material. No heat damage.
High speed laser cuttinghttp://www.youtube.com/watch?v=RQIJSsbvolc
Water jet cutting bullet-proof glasshttp://www.youtube.com/watch?v=KmUWA_oXDEQ
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Profile Cutting
EMMAT101A Engineering Materials and Processes
This is for cutting sheet material. Usually CNC• Flame Cut (Gas): Cheaper system, good for thick steel plate. Worst
quality.
• Plasma: Better finish than flame cut, but cheaper than laser.
• CNC router: Typically wood, plastic and soft metals (e.g. thin aluminium), often held down by vacuum onto a spoil board (MDF)
High speed laser cuttinghttp://www.youtube.com/watch?v=Zy3g4-D1ZeA
CNC Plasmahttp://www.youtube.com/watch?v=FHUs_u27IpE
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Video
Forming & Shaping Metal Davis, John. Warriewood, NSW : Classroom Video, c2002. DVD (22 min.) Hot Forming, Cold Forming, MachiningMt Druitt College Library: DVD 671.3/FORMRecommended Viewing: All sections.
EMMAT101A Engineering Materials and Processes
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EMMAT101A Engineering Materials and Processes
Graphical comparison of materials properties.
Wikipedia: Materials properties
Online Properties Resources.
Forming: Forging, Rolling, Extrusion, Machining
DoITPoMS: Dissemination of IT for the Promotion of Materials Science
http://www.youtube.com/user/CorusBCSATrainingCorusBCSATraining
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GLOSSARY
Hot formingCold formingRecrystallisationAnnealingWork HardeningStress RelievingDrawingERWCNCProfile CuttingPlasma CuttingLaser CuttingOxy CuttingWater Jet CuttingOpen Die ForgingUpset ForgingCavity Forging
EMMAT101A Engineering Materials and Processes
CoolantFacingTurningMetal SpinningRoll FormingExtrusionHot RollingCold RollingPowder MetallurgySinteringDrawingBlankingBendingStretching
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QUESTIONSCallister: NA Moodle XML: 10107 Processing
1. Define all the glossary terms.2. Explain which type of process would be used for making railway tracks and
compare it to the process of making road crash barriers. Explain the difference.3. Why are aluminium and copper based metals extruded, but not steel.4. Explain the process of making an ERW round pipe.5. Make a table comparing the various profile cutting technologies. Compare
machine cost, running cost, speed, accuracy, thickness, material range.6. CNC if far superior to manual control of a machining operation. Why do we still
have manual machines at all?7. A metal gear needs to be manufactured in the tens of thousands. Compare the
process options of powder metallurgy, machining, casting and forging. Include cost of die, material costs, running costs, speed, accuracy, product performance. (See: http://openlearn.open.ac.uk/mod/oucontent/view.php?id=399740§ion=3.9)
EMMAT101A Engineering Materials and Processes
