Materials Engineering and Technology

1. DEVAPRAKASAM DEIVASAGAYAM
Professor of Mechanical Engineering
Room:11, LW, 2nd Floor
School of Mechanical and Building Sciences
Email: devaprakasam.d@vit.ac.in, dr.devaprakasam@gmail.com
MEE1005: Materials Engineering and Technology (2:0:0:2)
Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

2. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933
MEE1005 MATERIALS ENGINEERING AND
TECHNOLOGY

3. Purpose of Engineering /Education/Research
Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933
There are two important purposes and driving force
behind the Engineering/Education/Research:
1. Minimum consumption of Energy and Materials
without sacrificing the efficiency and functionality.
2. Maximum conversion of Energy from one form to the
other, to identify or design highly efficient process or
system.

4. Purpose of Engineering /Education/Research
Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933
UNIT-I : Structure of Constitution of Alloys
Mechanism of Crystallization- Nucleation-Homogeneous and
Heterogeneous Nucleation- Growth of crystals- Planar
growth – dendritic growth – Cooling curves - Diffusion -
Construction of Phase diagram -Binary alloy phase diagram –
Cu-Ni alloy; Cu-Zn alloy and Pb-Sn alloy; Iron-Iron carbide
phase diagram – Invariant reactions – microstructural
changes of hypo and hyper-eutectoid steel- TTT and CCT
diagram

5. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

6. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

7. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

8. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

9. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

10. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

11. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

12. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

13. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

14. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

15. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933
When the solution above the transformation point is solid, rather than liquid, an
analogous eutectoid transformation can occur. For instance, in the iron-carbon system,
the austenite phase can undergo a eutectoid transformation to produce ferrite and
cementite, often in lamellar structures such as pearlite and bainite.

16. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933
Schematic representation of the formation of
pearlite from austenite; direction of carbon
diffusion indicated by arrows.

17. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933
Photomicrograph of a
eutectoid steel showing the pearlite
microstructure consisting of alternating
layers of α-ferrite (the light phase) and
Fe3C (thin layers most of which appear
dark).

18. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933
Consider a composition C0 to the left of the eutectoid, between 0.022 and 0.76 wt% C;
this is termed a hypoeutectoid (less than eutectoid) alloy.
Schematic representations of the microstructures for
an iron–carbon alloy of hypoeutectoid composition
C0 (containing less than 0.76 wt% C) as it is cooled
from within the austenite phase region to below the
eutectoid temperature.

19. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933
Schematic representations of the
microstructures for an iron–carbon alloy
of hypoeutectoid composition C0
(containing less than 0.76 wt% C) as it is
cooled from within the austenite phase
region to below the eutectoid
temperature.

20. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

21. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

22. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933
Proeutectoid signifies is a phase that forms (on cooling) before the eutectoid austenite
decomposes. It has a parallel with primary solids in that it is the first phase to solidify out
of the austenite phase. Thus, if the steel is hypoeutectoid it will produce proeutectoid
ferrite and if it is hypereutectoid it will produce proeutectoid cementite.

23. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933
Analogous transformations and
microstructures result for hypereutectoid
alloys, those containing between 0.76 and
2.14 wt% C, which are cooled from
temperatures within the phase field.
Schematic representations of the
microstructures for an iron–carbon alloy of
hypereutectoid composition C1 (containing
between 0.76 and 2.14 wt% C), as it is
cooled from within the austenite phase
region to below the eutectoid temperature.

24. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

25. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

26. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

27. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

28. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

29. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

30. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

31. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933

32. Devaprakasam D, Email: devaprakasam.d@vit.ac.in, Ph: +91 9786553933