Course – Manufacturing Technology

Course Overview

• Conventional Machining Processes

• Material Removal Process

• Casting

• Forging

• Welding

• Non Conventional Machining Process

• Abrasive Machining Process

Manufacturing - Basics

• Manufacturing is the use of machines, tools and labor to produce goods for use or sale. Raw materials are transformed into finished goods on a large scale. Such finished goods may be used for manufacturing other, more complex products, such as aircraft, household appliances or automobiles, or sold to wholesalers, who in turn sell them to retailers, who then sell them to end users – the "consumers".

• Key Words to know! – Just in Time Production

– Lean Manufacturing

– Kanban

– Toyota – Manufacturing Leaders!

Conventional Machining Processes

• Rolling

• Drawing

• Extrusion

• Blanking

• Fine Blanking

• Deep Drawing

Rolling

• Rolling, is a continuous bending operation in which a long strip of sheet metal (typically coiled steel) is passed through sets of rolls mounted on consecutive stands, each set performing only an incremental part of the bend, until the desired cross-section profile is obtained. Rolling is ideal for producing constant-profile parts with long lengths and in large quantities.

Drawing

• Drawing is a metalworking process which uses tensile forces to stretch metal. It is broken up into two types: sheet metal drawing and wire, bar, and tube drawing. The specific definition for sheet metal drawing is that it involves plastic deformation over a curved axis. For wire, bar, and tube drawing the starting stock is drawn through a die to reduce its diameter and increase its length.

Extrusion

• Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed or drawn through a die of the desired cross-section. The two main advantages of this process over other manufacturing processes are its ability to create very complex cross-sections and work materials that are brittle, because the material only encounters compressive and shear stresses. It also forms finished parts with an excellent surface finish.

Blanking and piercing

• Blanking and piercing are shearing processes in which a punch and die are used to modify webs. The tooling and processes are the same between the two, only the terminology is different: in blanking the punched out piece is used and called a blank; in piercing the punched out piece is scrap

Fine Blanking

• Fine blanking is a specialized form of blanking where there is no fracture zone when shearing. This is achieved by compressing the whole part and then an upper and lower punch extract the blank.[5] This allows the process to hold very tight tolerances, and perhaps eliminate secondary operations.

• Materials that can be fine blanked include aluminium, brass, copper, and carbon, alloy and stainless steels.

Fine Blanking

Deep Drawing

• Deep drawing is a sheet metal forming process in which a sheet metal blank is radially drawn into a forming die by the mechanical action of a punch.[1] It is thus a shape transformation process with material retention. The process is considered "deep" drawing when the depth of the drawn part exceeds its diameter.

Material Removal Process

Turning

Turning - Few Key terms

• Facing

• Parting

• Roughing

• Drilling

• Boring

• Knurling

• Threading

• Reaming

Casting

• In metalworking, casting involves pouring a liquid metal into a mold, which contains a hollow cavity of the desired shape, and then is allowed to solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process.

Casting – Pictorial Representation

Forging

• Forging is a manufacturing process involving the shaping of metal using localized compressive forces. Forging is often classified according to the temperature at which it is performed: '"cold," "warm," or "hot" forging.

• Common forging processes include: roll forging, swaging, cogging, open-die forging, impression-die forging, press forging, automatic hot forging and upsetting.

• Open Die Forging -Open-die forging is also known as smith forging.[6] In open-die forging, a hammer strikes and deforms the workpiece, which is placed on a stationary anvil.

• Cogging is successive deformation of a bar along its length using an open-die drop forge. It is commonly used to work a piece of raw material to the proper thickness. Once the proper thickness is achieved the proper width is achieved via edging.

Forging – Contd..

• Edging is the process of concentrating material using a concave shaped open die. The process is called edging, because it is usually carried out on the ends of the workpiece. Fullering is a similar process that thins out sections of the forging using a convex shaped die. These processes

prepare the workpieces for further forging processes.

Fullering Edging

Welding

• Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material (the weld pool) that cools to become a strong joint, with pressure sometimes used in conjunction with heat, or by itself, to produce the weld. This is in contrast with soldering and brazing, which involve melting a lower-melting-point material between the workpieces to form a bond between them, without melting the workpieces.

• Please check the link- it would be useful : http://en.wikipedia.org/wiki/List_of_welding_processes

Schematic Diagram

Arc Welding

TIG Welding

Resistance Welding

Non Conventional Machining Process

Abrasive Machining Process

• Abrasive machining is a machining process where material is removed from a workpiece using a multitude of small abrasive particles. Common examples include grinding, honing, and polishing. Abrasive processes are usually expensive, but capable of tighter tolerances and better surface finish than other machining processes.

• Mechanics of abrasive machining

Abrasive machining works by forcing the abrasive particles, or grains, into the surface of the workpiece so that each particle cuts away a small bit of material. Abrasive machining is similar to conventional machining, such as milling or turning, because each of the abrasive particles acts like a miniature cutting tool.

Few key words to be remembered!

Fixed (bonded) abrasive processes • Grinding • Honing, superfinishing • Tape finishing, abrasive belt machining • Buffing, brushing • Abrasive sawing, Diamond wire cutting, Wire saw • Sanding

Loose abrasive processes • Polishing • Lapping • Abrasive flow machining (AFM) • Hydro-erosive grinding • Water-jet cutting • Abrasive blasting • Mass finishing, tumbling

Abrasive Water jet Machining

• A water jet cutter, also known as a waterjet,[1] is a tool capable of slicing into metal or other materials (such as granite) using a jet of water at high velocity and pressure, or a mixture of water and an abrasive substance.

1 – High Pressure Water inlet 2- Jewel – Ruby or Diamond 3- Abrasive 4-Mixing Tube 5-Guard 6-Cutting water Jet 7-Cut Material

Abrasives

Conventional • Aluminum oxide (Corundum) • Silicon carbide • Emery • Pumice • Sand • Steel abrasive Superabrasives • Diamond • Cubic Boron Nitride (CBN), Borazon

References

• Kalpakjian, Serope; Steven R. Schmid (2003). Manufacturing Processes for Engineering Materials. Pearson Education.

• www.google.com

• en.wikipedia.org

• Notes taken down during classrooms!