Electro magnetic forming- metal spinning-peen forming

electro magnetic forming- metal spinning-peen forming

1. YoucaN Unit- 4- Sheet Metal Process 4.2- Electro magnetic forming- Metal spinning-Peen forming Compiled by Pravinkumar Kamatchi St.Josephs College of Engineering Assistant Professor

2. Special F orming Process Stretch Forming Explosive Forming Magnetic Pulse Forming Metal Spinning Peen Forming Super Plastic Forming Hydro Forming Rubber Pad Forming YoucaN

3. Electro magnetic forming YoucaN

4. YoucaN

5. YoucaN

6. YoucaN

7. YoucaN

8. Electro magnetic forming YoucaN

9. Electro magnetic forming The energy stored in a capacitor bank is discharged rapidly through a magnetic coil. EX: a ring shaped coil is placed over a tubular workpiece. Depends upon the shape of the die the tube will deform when the magnetic force pushes the metal. YoucaN

10. Electro magnetic forming The magnetic field produced by the coil crosses the metal tube(conductor) and so generates eddy currents in the tube. These current in turn, produces their own magnetic field. (see fig) YoucaN A localized electric current induced in a conductor by a varying magnetic field.

11. Electro Magnetic Forming The forces produced by the two magnetic fields oppose each other , consequently there is a repelling force between the coil and the tube . The forces g enerated collapse the tube over the inner piece. The higher the electrical conductivity of the workpiece , the higher the magnetic forces. It is not necessary for the workpiece material to have magnetic properties. (We can use some conducting layer strip) Flat magnetic coils are also available, for the operations of embossing and of shallow drawing on sheet metals. YoucaN

12. YoucaN

13. Electro Magnetic Forming- applications Magnetic-pulse forming is used for collapsing thin walled tubes over rods, cables and plugs, for compression- crimp sealing of automotive oil filter canisters , for bulging and flaring operations and for swaging end fittings on to torque tubes for the Boeing 777 aircraft. Producing b ulging of tube, shrinkage of tube YoucaN

14. Electro Magnetic Forming- Advantages and Disadvantages A dvantages Used to form uniform rate of forming Good surface finish products Time of operation is less as compared to conventional process Disadvantages: Non-conducting materials are not processed without aid of conducting materials It is limited for sheet metal forming process not an forming buld material. YoucaN

15. Metal spinning YoucaN

16. Metal spinning Metal spinning , also known as spin forming or spinning or metal turning most commonly, is a metalworking process by which a disc or tube of metal is rotated at high speed and formed into an axially symmetric part. Spinning can be performed by Manual or by a CNC lathe(power spinning) YoucaN

17. Manual Spinning Process: A circular block is centered on a lathe which is placed against a form block. The form block is mounted on the head stock of the spinning lathe. YoucaN Commercial applications include rocket nose cones, cookware , gas cylinders, brass instrument bells, and public waste receptacles Form block

18. Manual Spinning The blank is tightly held between form block and tail stock spindle. The required contour surface is made on the form block . The pressure is applied by the roller type forming tool which is placed on the tool post of the spinning lathe. Spinning roller is attached with a T-rest lever bars . The required shape is gradually formed by continuous application of pressure by the roller . During spinning process, some stretching and thinning of material take place . Spinning speed varies with size, design, type of metal and thickness of sheet metal. YoucaN

19. Manual Spinning It may suitable for both hot and cold working . Aluminium copper, brass and stainless steel can also be spun in spinning process . This process is mainly suitable for producing conica l shape parts and suitable for low volume production. Components produced in this process do not require any trimming or beading operations. Lubrication: Grease, linseed oil. YoucaN

20. Manual Spinning Advantage: Objects not be drawn by drawing operations can be easily formed in spinning Economical for low volume production Disadvantages Thinning takes place during spinning process More complex shapes required segmental chucks. Accuracy and quality of finished products mainly depend on the skill of the operator. YoucaN

21. Power spinning process Accuracy of spinning is less in manual spinning process. Even though segmental chucks used some complex shapes can not be formed. Also to reduce machining time, spinning machines are referred as power spinning. Nuclear controls method is used to control the form tool. Most of the power spinning process is done in HMT lathe. It is a semi automatic spinning and flow turning machine with a hydraulic copying attachment. YoucaN

22. Power spinning process Spinning of sheet metal is done automatically but the loading and unloading of sheet metal are done manually. The contour shape can be obtained with one pass of roller or multiple pass. Advantage- less time, more thickness can be easily handled, accurate one, high volume production. Application- flower pots, lamp shades, missile and radar units, jet plane components YoucaN

23. Peen Forming YoucaN

24. YoucaN

25. YoucaN

26. Peen forming Peen forming is a process of well established surface cleaning. In this process, a stream of metal shots is blasted against the surface of the blank to be made in to required shape . Used to produce curvatures on thin sheet metals by shot peening one surface of the sheet. Surface of the sheet is subjected to compressive stresses . The local plastic deformation in metal improves the fatigue strength. The process also induces compressive residual stresses ( the stress present in an object in the absence of any external load or force ), which improve the fatigue ( structural damage from repeated loading ) strength of the sheet . YoucaN

27. YoucaN Surface contains tension will fail first. So our idea is creating compression on both the sides

28. YoucaN

29. YoucaN

30. Peen forming Surface spreads plastically, due to that the crack propagation in a material is eliminated. (crack initiation is avoided so fatigue strength increases a lot) Shot peening increase fatigue life up to 1000%. YoucaN

31. YoucaN

32. YoucaN

33. YoucaN

34. YoucaN

35. YoucaN

36. Peen forming Advantages: Complex contours can be produced easily Peening is also used as salvage operations for correcting bent Does not required any punch and die. Disadvantage: Requires longer time for forming the required shape, requires additional devices for forcing out metal shots. YoucaN

37. YoucaN

38. YoucaN I hope you are here…