functionally graded structures,metal matrix composite,processing techniques and areas of applications

1. M.Tech (Machine Design)
Department Of Mechanical Engineering
Gudlavalleru Engineering College
Guided by presented by
Mr. P.N.S.Srinivas, M.Tech(PhD) A. Sabiha Khathun
Asst.professor M.Tech(16481D1501)
FUNCTIONALLY GRADED MATERIALS - AN
OVERVIEW

2. • Introduction
• Definition
• Origin of FGM
• Classification of FGM
• Metals Vs FGM
• Special features of FGM
• Processing techniques
• Applications of FGM
• Scope and conclusion
Contents

3. Introduction
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion
• A new class of composite materials known as functionally graded
materials (FGMs) has drawn considerable attention of the scientific
community.
• FGMs exist in nature like wood, bamboo, etc. Even human bones
are also FGM.
• The aircraft and aerospace industry and the computer circuit
industry make wide use of FGM that can withstand very high
thermal gradients. This is normally achieved by using a ceramic
layer connected with a metallic layer.

4. • Functionally graded materials(FGM) can be obtained by layered
mixing of two materials of different mechanical properties with
different volume ratio by gradually changing from layer to layer such
that the first layer has only a few particles of second phase and the
last has maximum volume ratio of the first phase.
• In FGMs, the different micro-structural phases have different
functions. The overall FGMs attain the multi-structural status from
their property gradation.
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and conclusion
Definition

5. FGM Structure
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and conclusion

6. 70g of A+30g of B
60g of A+ 40g of B
100g of A
20g of A+80g of B
100g of B
Material A
Material B
FGM structure
D
I
E

7. Steel and Aluminium FGM

8. • Bones have functional grading.
• Skin is also graded to provide certain toughness, tactile and elastic
qualities as function of skin depth and location on the body.
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and conclusion
Some naturally occurring FGMs

9. •In technical world functionally graded materials were first
proposed around 1984 in Japan during a space plane project.
• In recent years this concept has become more popular in
Europe, particularly in Germany.
Introduction
Definition
Origin
Classification
Metals vs. FGM
Processing techniques
Applications
Scope and Conclusion
Origin of FGM

10. • Space shuttle moves at about 28,000km/hr, the orbiter hits air
molecules and builds up heat from friction (30000F,or16500C).
• The orbiter is covered with ceramic insulating material designed to
protect it from this heat.
• The joining of ceramics to metals is of great engineering
significance for various advanced technologies, including high
temperature structural applications.
Introduction
Definition
Origin
Classification
Metals vs. FGM
Processing techniques
Applications
Scope and Conclusion

11. • Large number of engineering components and tools require material
performance by varying with location.
 The body of gear must be tough, whereas its surface must be hard and
wear resistant.
 A knife needs only to be hard at its cutting edge, elsewhere the material
must be strong and tough.
• Many of most demanding current applications are fall under this category.
• Stress concentrations are reduced, if the transition from one material to other
is gradual.
• The magnitude of thermal stress at the critical locations can be controlled.
Why FGM ?

12. • FGM provide capabilities for part integration.
Several metallic components can be replaced by a single FGM component.
• FGM structures provide in-service monitoring or online process monitoring
with the help of embedded sensors.
• The matrix material binds the fibers together and transfers the load to the fibers.
• The matrix isolates the fibers so that individual fibers can act separately.
This stops or slows the propagation of a crack.
• The matrix provides a good surface finish quality and aids in the production of
net-shape or near-net-shape parts.
Special features of FGM

13. Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and conclusion
PROPERTY COMPARISON
METALS VS FGMS

14. Types of gradation
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion
• Chemical composition gradient
• Porosity Gradient
• Microstructure gradient

15. • As the composition of material is varied from one material into the
other, it will result in different phases with different chemical
compositions.
• The different phases that are produced are dependent on the
compositional quantity and manufacturing conditions of the
reinforcing material.
Chemical composition gradient
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion

16. •Functionally the porosity in the material is made to change
with the change in the spatial position in the bulk material.
•The pore size gradation can be achieved by varying the
powder particle sizes that are used at different locations in the
bulk material during the gradation process.
Porosity gradient
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion

17. •It can be achieved during the solidification process, such that the surface of the
material is quenched.
•The core of the same material is allowed to cool down slowly, which would
help to produce different microstructures from those on the surface of the
material to the innermost part.
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion
Microstructure gradient FGM
Flow of Liquid metal Flow of Cooling Water

18. According to process of manufacturing:
Thin FGM and Bulk FGM
•Thin FGM: It consists of relatively thin sections or thin
surface coating
• Bulk FGM: It consists of volume of materials which
require more labor intensive processes
Process of manufacturing
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion

19. Thin FGM
• Vapour Deposition Technique(i.e., CVD,PVD)
• Plasma spraying
• Self-propagating high temperature synthesis(SHS)
• Ion beam assisted deposition(IBAD)
Bulk FGM
• Powder Metallurgy
• Centrifugal Method
• Solid Freeform fabrication method
Processing techniques
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion

20. • PVD is characterized by a process in which the material goes
from a condensed phase to a vapor phase and then back to a thin
film condensed phase.
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion
Physical vapor deposition diagram
Physical Vapour Deposition(PVD) technique

21. Chemical Vapour Deposition(CVD) technique
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion
• Film is formed by chemical reaction between gaseous
compounds.

22. Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion
SELF PROPAGATAING HIGH TEMP.
SYNTHESIS (SFS)

23. SHS = combustion + structure formation
SELF PROPAGATAING HIGH TEMP.
SYNTHESIS (SFS)
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion

24. Powder metallurgy method
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion

25. Centrifugal method
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion

26. • SFF refers to a category of manufacturing process in
which parts are built by deposition of one cross sectional
layer of material on top of the next.
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion
Solid free form fabrication(SFF)

27. Applications of FGL composites

28. Aerospace and aeronautics
• Advanced aircraft and aerospace engineering
• Rocker heat shields
• TBC Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion

29. Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion

30. Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion
Many defense applications now rely on unique properties
delivered by modern composite materials.

31. Power plant
• TBC
• Heat exchanger
Manufacturing
• Machine tools
• Forming and cutting tools
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion

32. Biomaterials
•Artificial bones and teeth
Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion

33. Introduction
Definition
Origin
Metals vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion

34. • Solid freeform fabrication technique offers a greater
advantage for producing FGM, but there are still lots of
issues that need to be resolved with this promising
technology.
• Research focus on variation of gradient material with respect
to thermal stress relaxation of the material.
• A proper database of gradient material (including material
system, parameters, material preparation and performance
evaluation) is to be developed.
Introduction
Definition
Origin
Composite vs. FGM
Classification
Processing techniques
Applications
Scope and Conclusion
Recent researches in FGM

35. • Functionally graded materials are very important in engineering and other
applications but the cost of producing these materials makes it prohibitive
in some applications.
• Flexibility in manufacturing of FGM.
• For creep problems, functionally graded component is better choice for
the design.
Conclusion