Anglicky v odborných předmětech"Support ofteachingtechnicalsubjects in English“ Tutorial: Engineering technology Topic: Volumeforging – Extrusion Prepared by: Ing. Elena Nová Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/04.0002 je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky.
Volume forging – Extrusion • Extrusion is a technology which can be used at higher, medium and cold temperatures. Forged material is moved in directions determined by the tool’s construction- extrusion die. • Product is called • extrusion punch.
Volume forging – Extrusion Extrusion technology: Metals with low forging strength as is aluminum and its alloys can be extruded in one operation. Steel and other metals use more operations.
Volume forging – Extrusion • It is necessary to treat the material by straitening and cutting before actual extrusion. After that follows surface cleaning and phosphate. • Extrusion die consists of extrusion punch and extrusion die. • Lubricant for extrusion at higher temperatures is glass. • Cold extrusion uses oil.
Volume forging – Extrusion • Extrusion is divided: • Hot extrusion • Is used for full and hollow profiles with difficult cross sections which cannot be made by rolling. Cold extrusion • Is used for thin walled products, cartridges, tubes, spray cans. • Production is very economic.
Volume forging – Extrusion • Extrusion is divided according to direction on: • Forward • Backward • Combined • Sidewise • Radial
Volume forging – Extrusion At forward (direct) extrusion is material moving in the same direction as extrusion punch. It is used for forging pivots, bolts, bushes, products with constant cross section. • Princip dopředného protlačování(1, 3 – die, 2, 4 - punch, a, – punch, • b – wiper, c – die, d– ejector)
Volume forging – Extrusion • At backwards extrusion, material moves in opposite direction. It is used for manufacturing of hollow extrusions where wall thickness is very thin compared to its diameter. • Princip zpětného protlačování • 1, 3 – die, 2, 4 - punch, • a, – punch, b – wiper, c – die, • d - ejector
Volume forging – Extrusion • Combined (compounded) extrusion • Very stressed, profiled products are made in this manner. Principle of combined extrusion 1, 3 – die, 2, 4 - punch, a, – punch, b – wiper, c – die, d – ejector)
Volume forging – Extrusion • Side and radial extrusion • At side extrusion is material moving perpendicularly to direction of extrusion punch. • Radial extrusion is a forging where material and tool parts are moving in radial direction to axis of extruded product. • Principle of side (left and middle) and radial extrusion
Volume forging – Extrusion • Hydrostatic extrusion, semi-finished product is inserted in liquid of very high pressure. By the all-dimensional tension is material ductility increased.
Answer the questions: • What kinds of extrusion do you know? • Divide extrusions in accordance to flow direction. • Describe construction of extrusion tool. • What material and method do we use for cold extrusion? • What material and method do we use for hot extrusion?
Translate: • Translate and describe:
Used literature • http://www.ksp.tul.cz/cz/kpt/obsah/vyuka/skripta_tkp/sekce/04.htm