TAFE NSW -Technical and Further Education Commission ENMAT101A Engineering Materials and Processes Associate 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 TextSection Higgins RA & Bolton, Materials for Engineers and Technicians, 5th ed, Butterworth Heinemann Ch 7 Additional ReadingsSection Sheedy, P. A, Materials : Their properties, testing and selectionCh 13 Callister, W. Jr. and Rethwisch, D., 2010, Materials Science and Engineering: An Introduction, 8th Ed, Wiley, New York. N.A. Ashby, M.F., Materials Selection in Mechanical Design, 4 th Ed, Butterworth Heinemann, Oxford, UK. Ch 13

TAFE NSW -Technical and Further Education Commission EMMAT101A Engineering Materials and Processes Ashby: Fig 13.2 The classes of processes

TAFE NSW -Technical and Further Education Commission 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 Processes Forging Hot-rolling

TAFE NSW -Technical and Further Education Commission 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.

TAFE NSW -Technical and Further Education Commission Hot-working processes: Hot-Rolling (Higgins 7.2.2) EMMAT101A Engineering Materials and Processes Cobble: Cobble 2: Hot Rolling (Billet to plate/sheet): Dalarna University (Creative Commons) Breaking down billets (large thick slabs cast from the furnace) into successively thinner plate, and finally sheet. HD-720 Fun and Games with Hot Rolling… “Cobble” = British terminology “Miss-roll = US terminology

TAFE NSW -Technical and Further Education Commission 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.

TAFE NSW -Technical and Further Education Commission 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? Extrusion bridge die making a hollow section product. Note: in reality, the die and ring are held together.

TAFE NSW -Technical and Further Education Commission Hot-working processes: Extrusion (Higgins 7.2.3) EMMAT101A Engineering Materials and Processes Heated to about 900 o F (480 o C) to keep it well above the recrystallisation temperature (150 o C). 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.

TAFE NSW -Technical and Further Education Commission Hot-working processes 3 (Higgins 7.2) EMMAT101A Engineering Materials and Processes Other Hot Working Processes Hot forming of Coil Springs: Friction Welding:

TAFE NSW -Technical and Further Education Commission 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 Processes Cold-rolling Drawing Cold-pressing and deep-drawing Bolts: Spinning Stretch-forming Coining and embossing Impact-extrusion

TAFE NSW -Technical and Further Education Commission 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 Tower

TAFE NSW -Technical and Further Education Commission Cold-working processes: Drawing (Higgins 7.3.2) EMMAT101A Engineering Materials and Processes Cold Drawing of Hexagonal Bar

TAFE NSW -Technical and Further Education Commission Cold-working processes: Cold Pressing and Deep Drawing (Higgins 7.3.3) EMMAT101A Engineering Materials and Processes Forming Bolts

TAFE NSW -Technical and Further Education Commission Cold-working processes: Spinning (Higgins 7.3.4) EMMAT101A Engineering Materials and Processes Metal Spinning

TAFE NSW -Technical and Further Education Commission Cold-working processes: Stretch-forming (Higgins 7.3.5) EMMAT101A Engineering Materials and Processes Stretch Forming

TAFE NSW -Technical and Further Education Commission Cold-working processes: Coining and embossing (Higgins 7.3.6) EMMAT101A Engineering Materials and Processes Stamping

TAFE NSW -Technical and Further Education Commission Cold-working processes: Impact Extrusion (Higgins 7.3.7) EMMAT101A Engineering Materials and Processes Impact Extrusion

TAFE NSW -Technical and Further Education Commission Cold-working processes: Roll Forming EMMAT101A Engineering Materials and Processes Roll Forming – Roofing Spiral Ducting ERW Pipe Forming (5” or 125mm)

TAFE NSW -Technical and Further Education Commission 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: Uses of powder-metallurgy Cemented carbides Sintered-bronze bearings Powder Metallurgy

TAFE NSW -Technical and Further Education Commission 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 – Lathe High Speed Video: Milling Cutter Machining Centre: 5 axis various jobs

TAFE NSW -Technical and Further Education Commission 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 cutting Water jet cutting bullet-proof glass

TAFE NSW -Technical and Further Education Commission 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 cutting CNC Plasma

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

TAFE NSW -Technical and Further Education Commission 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 CorusBCSATraining

TAFE NSW -Technical and Further Education Commission 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 EMMAT101A Engineering Materials and Processes Coolant Facing Turning Metal Spinning Roll Forming Extrusion Hot Rolling Cold Rolling Powder Metallurgy Sintering Drawing Blanking Bending Stretching

TAFE NSW -Technical and Further Education Commission QUESTIONS Callister: NA Moodle XML: 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: EMMAT101A Engineering Materials and Processes