1 / 27

Mechanical Deformation of Metals

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.

malise
Download Presentation

Mechanical Deformation of Metals

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ENMAT101A Engineering Materials and ProcessesAssociate Degree of Applied Engineering (Renewable Energy Technologies)Lecture 7 – Mechanical shaping of metals

  2. Mechanical Deformation of Metals EMMAT101A Engineering Materials and Processes

  3. Ashby: Fig 13.2 The classes of processes EMMAT101A Engineering Materials and Processes

  4. Hot-working processes (Higgins 7.2) Hot Working processes are carried out above the recrystallisation temperature of the material. 7.2 Hot Working Processes 7.2.1 Forging 7.2.2 Hot-rolling EMMAT101A Engineering Materials and Processes

  5. Hot-working processes: Forging (Higgins 7.2.1) 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. EMMAT101A Engineering Materials and Processes

  6. Hot-working processes: Hot-Rolling (Higgins 7.2.2) 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. Fun and Games with Hot Rolling… “Cobble” = British terminology “Miss-roll = US terminology HD-720 Cobble: http://www.youtube.com/watch?v=NnqZ-ybpdhQ Cobble 2: http://www.youtube.com/watch?v=v4p-YCtbhMQ EMMAT101A Engineering Materials and Processes

  7. Hot-working processes: Extrusion (Higgins 7.2.3) 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) 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. openlearn.open.ac.uk EMMAT101A Engineering Materials and Processes

  8. Hot-working processes: Extrusion (Higgins 7.2.3) Extruding a hollow shape is an obvious problem. How do you hold the die that forms the hole? Extrusion bridge die making a hollow section product. Note: in reality, the die and ring are held together. http://openlearn.open.ac.uk/mod/oucontent/view.php?id=399740&section=3.5 EMMAT101A Engineering Materials and Processes

  9. Hot-working processes: Extrusion (Higgins 7.2.3) 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. 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 EMMAT101A Engineering Materials and Processes

  10. Hot-working processes 3 (Higgins 7.2) 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 EMMAT101A Engineering Materials and Processes

  11. Cold-working processes (Higgins 7.3) Cold Working processes are carried out below the recrystallisation temperature of the material. See text: 7.3 Cold Working Processes 7.3.1 Cold-rolling 7.3.2 Drawing 7.3.3 Cold-pressing and deep-drawing Bolts: http://www.youtube.com/watch?v=7PQyant3mCc 7.3.4 Spinning 7.3.5 Stretch-forming 7.3.6 Coining and embossing 7.3.7 Impact-extrusion EMMAT101A Engineering Materials and Processes

  12. Cold-working processes: Cold Rolling (Higgins 7.3.1) Cold Rolling Steel Sheet: Steelmaking: Cold Rolling by CorusBCSATraining Roll Curving Steel plate for Wind Turbine Tower http://www.tsgnorthamerica.com EMMAT101A Engineering Materials and Processes

  13. Cold-working processes: Drawing(Higgins 7.3.2) Cold Drawing of Hexagonal Bar http://www.youtube.com/watch?v=72JWZAWZp5Q EMMAT101A Engineering Materials and Processes

  14. Cold-working processes: Cold Pressing and Deep Drawing(Higgins 7.3.3) Forming Bolts http://www.youtube.com/watch?v=7PQyant3mCc EMMAT101A Engineering Materials and Processes

  15. Cold-working processes: Spinning (Higgins 7.3.4) Metal Spinning http://www.youtube.com/watch?v=7PQyant3mCc EMMAT101A Engineering Materials and Processes

  16. Cold-working processes: • Stretch-forming (Higgins 7.3.5) Stretch Forming http://www.youtube.com/watch?v=eSVi7dC5L_Q EMMAT101A Engineering Materials and Processes

  17. Cold-working processes: • Coining and embossing (Higgins 7.3.6) Stamping http://www.youtube.com/watch?v=I7uBmlwxXRU EMMAT101A Engineering Materials and Processes

  18. Cold-working processes: • Impact Extrusion (Higgins 7.3.7) Impact Extrusion http://www.youtube.com/watch?v=zMhVPId-pRA EMMAT101A Engineering Materials and Processes

  19. Cold-working processes: • Roll Forming Roll Forming – Roofing http://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 EMMAT101A Engineering Materials and Processes

  20. Powder Metallurgy (Higgins 7.4) 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-metallurgy 7.4.2 Cemented carbides 7.4.3 Sintered-bronze bearings Powder Metallurgy http://www.youtube.com/watch?v=_0wd8sgNIOg EMMAT101A Engineering Materials and Processes

  21. Machining metals (Higgins 7.5) 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 Centre: 5 axis various jobs http://www.youtube.com/watch?v=0LCaRqQ8Qf8 High Speed Video: Milling Cutter http://www.youtube.com/watch?v=IUBQN1JfY80 Machining a large shaft – Lathe http://www.youtube.com/watch?v=ObsvfP5Nrw4 EMMAT101A Engineering Materials and Processes

  22. Profile Cutting • 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 cutting http://www.youtube.com/watch?v=RQIJSsbvolc Water jet cutting bullet-proof glass http://www.youtube.com/watch?v=KmUWA_oXDEQ EMMAT101A Engineering Materials and Processes

  23. Profile Cutting • 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 cutting http://www.youtube.com/watch?v=Zy3g4-D1ZeA CNC Plasma http://www.youtube.com/watch?v=FHUs_u27IpE EMMAT101A Engineering Materials and Processes

  24. Video Forming & Shaping Metal Davis, John. Warriewood, NSW : Classroom Video, c2002. DVD (22 min.) Hot Forming, Cold Forming, Machining Mt Druitt College Library: DVD 671.3/FORM Recommended Viewing: All sections. EMMAT101A Engineering Materials and Processes

  25. Online Properties Resources. Graphical comparison of materials properties. DoITPoMS: Dissemination of IT for the Promotion of Materials Science Wikipedia: Materials properties Forming: Forging, Rolling, Extrusion, Machining CorusBCSATraining http://www.youtube.com/user/CorusBCSATraining EMMAT101A Engineering Materials and Processes

  26. GLOSSARY • Hot forming • Cold forming • Recrystallisation • Annealing • Work Hardening • Stress Relieving • Drawing • ERW • CNC • Profile Cutting • Plasma Cutting • Laser Cutting • Oxy Cutting • Water Jet Cutting • Open Die Forging • Upset Forging • Cavity Forging Coolant Facing Turning Metal Spinning Roll Forming Extrusion Hot Rolling Cold Rolling Powder Metallurgy Sintering Drawing Blanking Bending Stretching EMMAT101A Engineering Materials and Processes

  27. QUESTIONS Callister: NA Moodle XML: 10107 Processing • Define all the glossary terms. • 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. • Why are aluminium and copper based metals extruded, but not steel. • Explain the process of making an ERW round pipe. • Make a table comparing the various profile cutting technologies. Compare machine cost, running cost, speed, accuracy, thickness, material range. • CNC if far superior to manual control of a machining operation. Why do we still have manual machines at all? • 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&section=3.9) EMMAT101A Engineering Materials and Processes

More Related