severe plastic deformation introduction, techniques, advantages, application

1. SEVERE PLASTIC DEFORMATION
(An approach to refine microstructure, improve the strength and enhance ductility)
Govt. Engineering College, Bikaner
Mechanical Engineering Department
Submitted By:
Om Prakash Kumawat
14eebme733
2nd Shift
Guided By:
Dr. Dharmendra Singh
A Seminar Presentation
on
March 2018

2. Outline
Introduction
Techniques.
Advantages
Applications
conclusion

3. Introduction
It is process of refining the microstructure of material into
ultra-fine grains(UFG).
 size< 10 μm.
SPD
coarse-grained materials
Ultra fine grain material

4. SPD works on hall- patch relation.
possible to induce large strain without changing the
dimension of work piece.
SPD

5. High strain rate.
No dimension change.
High strength.
High fracture toughness.
No texture.
Minimize material rate.
What we can achieve by SPD

6. Material tetrahedron
Increase
Performance
Change
properties
microstructure
Processing/Techniques

7. Equal Channel angular pressing
Segal ,1970, Russia

8. Less strain
Medium strain
High strain
Route A
Route B
Route C
Ansys simulation
limitation
It is Batch process

9. High pressure torsion
e =ln(ɸr/l)
An high strain is introduced
between sample and the anvil
surface.
No cross section of sample is
changed.
Required high pressure And force.
Only it can works on small samples only.
Limitation

10. Repetitive corrugation and straightening (RCS)
2001
Possible for only sheet samples.
Continuous process

11. Accumulative Roll Bonding (ARB)
It deform stack of two sheets of equal thickness
The rolled sheet cut in half and fold then repeat the same
process.
The sheets are reduced up to 50 %

12. Multi-Axial Compression / Forging
It deform rectangular cross section work piece.
Series of compression are done to retain the size.
The loading direction is changed after 90 ⁰.

13. Friction Stir Processing
This works on friction stir welding
principle.
A rotating tool with pin and shoulder
is used.
Friction between tool surface
and work piece a heating occur that
softens and plasticizes

14. Asymmetric Rolling
One roll has higher velocity than other.
This is done by changing the size of rolls.
This create a region in which friction forces on top and
bottom are in opposite.
Limitation
The work piece Cross section
changed.

15. Advantages
Multiple passes is possible with same cross section
It can conduct at room temperature
Large bulk sample are possible
Higher strength and better fatigue properties with fine
Microstructure.
Ability to design lighter components with ultrafine grain
materials.

16. future application
Medical implants
The weight has to be minimized
The strength should high
By SPD A good amount of weight can be reduced
So

17. Aerospace industry
In this also light weight
material are required

18. Automobiles engine parts
Required good strength.
Low fracture tendency.

19. conclusion
Fine grained materials produced by SPD can be generated on
a laboratory scale in an effective and simple way.
several details need some further clarifications.
The thermal stability of submicron structures is good
a complete picture of yield behavior and strain hardening is
still missing.