ENGINEERING MANUFACTURING METHODS

Subjects to be Covered: Turning Milling Drilling Welding Drop forging Press forging Upset forging

Hardening Die casting Sand casting Investment casting Permanent mould casting

TURNING Achieved by using a lathe to shape material into cylindrical profiles. Advantages: high accuracy, high work volume, automation with feed and CNC, creative / interesting, versatile Disadvantages: limited to producing cylindrical profiles, machine prices, tooling failure can lead to scrapped work, machines are hazardous, require time to master using, high power consumption, machine setting takes time Safety: keep away from rotational parts especially loose clothing & dangling objects, care with sharp tooling and sharp edges of work

MILLING Achieved by using a Milling Machine to shape material into rectangular / square profiles Advantages: high accuracy, high work volume, automation with feed and CNC, creative / interesting, versatile Disadvantages: limited to producing cylindrical profiles, machine prices, tooling failure can lead to scrapped work, machines are hazardous, require time to master using, high power consumption, machine setting takes time Safety: for the student to tell

DRILLING Achieved by using a selection of drill machines to produce round holes of different sizes and depths by rotating drill tool Advantages: ability to produce a wide range of hole diameters to a set specified depths Disadvantages: limited to producing holes of a circular profile Safety: for the student to tell

WELDING Achieved by applying electrical supply to metal wire / rods to produce molten metal for use in bonding neighbouring pieces of metal together Advantages: quick and easy in the hand of an expert to provide a strong and permanent joint Disadvantages: if incorrect electrical supply is selected this can produce poor quality joint which will be unsuitable for purpose Safety: for the student to tell

DROP FORGING Achieved by heating metal and hammering it in to a special die (cast die) to produce a final product Advantages: one advantage is it produces products which need to be strong and durable Disadvantages: poses a dangerous environment to the workers Safety: for the student to tell https://www.youtube.com/watch?v=Wf4NDkiZw6E

PRESS FORGING Achieved by forcing the heated metal into a specially crafted shape of die via either pressing or hammering into place until the desired shape has been formed Advantages: change the shape and interior of the workpiece at the same time Disadvantages: can only be used for short production runs due to the high tooling cost Safety: for the student to tell

UPSET FORGING Achieved by increasing the diameter of the hot metal to be shaped by decreasing its length Advantages: gives the material being casted greater strength due to the material grain flow is oriented to the component's shape Disadvantages: again the high cost of the tooling involved Safety: for the student to tell Most forging methods: https://www.youtube.com/watch?v=XTU0Z-FkhtU

MATERIAL STRESSES

HARDENING Achieved by heating a metallic to a glowing bright orange colour, followed by quenching in water or oil to improve the hardness properties in the material Advantages: absolutely effective in achieving the task required Disadvantages: limited to steels with a high carbon content Safety: for the student to tell

DIE CASTING Achieved by forcing molten metal under high pressure into a mold cavity. The mould cavity is created using two hardened tool steel dies which have been machined into shape and work similarly to an injection mould during the process. Advantages: excellent in achieving high accuract Disadvantages: limitation in producing castings to a size and weight Safety: for the student to tell

SAND CASTING Achieved by pouring molten metal into a bespoke mould made from sand to form a metallic structure once cooled down Advantages: can form large parts and complex shapes Disadvantages: poor surface finish and tolerance Safety: for the student to tell https://www.youtube.com/watch?v=K8SYhISGxN4

INVESTMENT CASTING Achieved by pouring molten metal into a bespoke made ceramic mould, which is then broken to remove the metallic parts once cooled Advantages: has the ability to make intricate parts to a high accuracy Disadvantages: its initial costs and production size limitation Safety: for the student to tell https://www.youtube.com/watch?v=UrUsaGussfc

PERMANENT MOULD CASTING Achieved by pouring molten metal into a reusable mould which is then removed from the moulded object once cooled Advantages: mould is reusable and produces to a high accuracy Disadvantages: high tooling costs and limited to low point cooling metals Safety: for the student to tell https://www.youtube.com/watch?v=wazTPUAOCuY

References: http://www.cottandco.com/en/lots/colchester-student-1800-gap-bed-centre- lathe---1 http://www.ebay.com/bhp/welding-machine http://www.directindustry.com/prod/imcar/product-16952- 1704484.html?utm_source=ProductDetail&utm_medium=Web&utm_content=Si milarProduct&utm_campaign=CA http://www.hellomolding.com/sale-431808-hot-runner-h13-nak80-skd61-die- casting-mould-with-single-cavity-multi-cavity.html http://ppcpinc.com/investment-casting-advantages-disadvantages/