Materials Science and
Engineering Thermodynamics
MSE 503
Prof. Dr. Yaşar Akdoğan
yasarakdogan@iyte.edu.tr
Engineering Faculty D Block, Office 69
Friday
9.45 - 12.30
MUH-D-Z-31
Teams Code: yidyjj7
• 03 October_Introduction
• 10 October_First law of thermodynamics
• 17 October _ Questions with First law / Second law of thermodynamics
• 24 October _Second law of thermodynamics/Questions with Second law
• 31 October _Fundamental of Thermodynamics Equations
• 07 November _1st Midterm
• 14 November _ Enthalpy of reactions and Third Law
• 21 November _ Phase Equilibrium in a One-Component System
• 28 November _ The Behaviour of Gases
• 05 December_The Behaviour of Solutions
• 12 December _2nd Midterrm
• 19 December _ Reactions Involving Gases
• 26 December _ Reactions Involving Pure Condensed Phases and a Gaseous Phase
• 02 January_Review
Textbooks:
Introduction to the Thermodynamics of Materials,
David E. Laughlin , David R. Gaskell
Thermodynamics in Material Science, Robert DeHoff
Course Evaluation:
1st Midterm Exam: 25%
2nd Midterm Exam: 25%
Final Exam: 50%
Textbook:
Introduction to the
Thermodynamics of Materials
David E. Laughlin , David R. Gaskell
5
Classical thermodynamics is
a branch of physics
originating in the 19th
century as scientists were
first discovering how to build
and operate steam engines,
which primarily led to the
industrial revolution.
6
•The steam engine transforms thermal energy (from steam) into
mechanical energy (motion/work).
•It was one of the key technologies of the Industrial Revolution,
powering trains, ships, and factories.
Thermodynamics was developed to understand the nature of
these heat engines and to increase the efficiency of
transition between heat and work.
HEAT
WORK
7
“What is energy?”
Energy is the capacity to do work,
it is essentially an abstract concept.
It is not a concrete object that you can see or touch.
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Energy cannot be measured directly and thus has no
definite value.
Thermodynamics deals with energy and its transitions
and tells us that the energy differences can be
measured by heat and work removed or added.
Heat and work are not stored as such anywhere, but
are the two forms of energy transfer.
9
Thermodynamics of
materials
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Materials store energy through the arrangement and motion of the
constituent atoms, and so the material changes its atomic structure
during undergoing a change in its thermodynamic state.
Thermodynamics thus affects materials microstructures, defect
concentration, atomic ordering, etc.
In many cases, thermodynamics of materials is a crucial factor to
good engineering design and performance forecast of manufactured
components, parts, devices, tools, machines, etc..
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Chapter 1
Introduction and Definition of Terms
The term thermodynamics is related to the two Greek words therme
and dynamikos, which translate into English as “heat” and “power” (or
“movement”), respectively.
Thermodynamics is the physical science that focuses on the
relationship between energy and work as well as the equilibrium states
and variables of systems that are being investigated.
12
• Heat (thermal energy) is the total energy of molecular motion in a substance.
Heat is also a process in which energy is transferred from one region to
another down a temperature gradient.
• Temperature is a measure of how hot or cold something is; a measure of the
average kinetic energy of the particles in an object, which is a type of energy
associated with motion. Temperature determines the way of heat flow. 13
Temperature = Kinetic Energy per molecule (average).
Heat (thermal energy) = Total energy from the motion of all
molecules.
14
• Temperature is not energy, but a measure of it. Heat is energy.
• If we add heat, the temperature will become higher. If we remove heat the
temperature will become lower.
• Higher temperatures mean that the molecules are moving, vibrating and
rotating with more energy.
• If we take two objects which have the same temperature and bring them into
contact, there will be no overall transfer of energy between them because the
average energies of the particles in each object are the same. But if the
temperature of one object is higher than that of the other object, there will be
a transfer of energy from the hotter to the colder object until both objects
reach the same temperature.
15
«Energy cannot be created or destroyed»
Thermodynamics deals with the conservation of energy
as well as the conversion of the various forms of energy
into each other or into work.
16
Heat flow from hot place to cold place can be used to rotate turbine
and then we get work.
17
• Heat and work are two different ways of transferring
energy from one system to another.
• Heat is the transfer of thermal energy between systems,
while work is the transfer of mechanical energy between
two systems.
18
A locomotive or engine of a train
19
System and Surrounding
A system in thermodynamics is the collection of matter that is being studied.
Everything external to the system is called the thermodynamic surroundings, and
the system is separated from the surroundings by the system boundaries.
These boundaries may either be fixed or movable.
20
3 kinds of systems
It is convenient to characterize systems by the kinds of interactions that are
allowed between them and their surroundings.
21
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The boundaries or walls of the system are classified as follows:
• Adiabatic : No thermal energy can pass through.
• Diathermal : Thermal energy can pass through.
• Permeable : Matter can pass through.
• Impermeable : Matter cannot pass through.
• Semipermeable : Some components are able to pass through, while others are
not.
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24
25
Internal energy, enthalphy,
entropy
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27
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(State functions)
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30
The relationship between the
dependent variable V and
the independent variables P and T can be
expressed as
V = V(P,T)
Is V path function or state function?
31
Since the volume of the gas is a state function has
exact differential
32
1-a-2
V = V2 −V1
1-b-2
Since the volume of the gas is a state function
T
33
The change in volume caused by changing the state
of the gas from state 1 to state 2 depends only on
the volumes at states 1 and 2 and is independent of
the path taken by the gas between the states.
This is because the volume of the gas is a state
function and the Equation is an exact differential of
the volume, which is a thermodynamic state
variable.
34
What is the exact differantial of V?
35
y,z
36
The isothermal compressibility coefficient
The coefficient of thermal expansion
37
Relative volume change of a fluid or solid as a response to
a pressure change
Relative volume change of a fluid or solid as a response to
a temperature change
38
the coefficient of thermal expansion, α, is defined as the fractional
increase of the volume of the gas, with the change in temperature at
constant pressure;
where V is the volume of 1 mole of the gas at 273.15 K, lets say 22.4 L.
This hypothetical gas is called the perfect or ideal gas, and
it has a value of
α =1/273.15
every 1 degree temperature rise, increases the volume with a
(1/273.15) X (22.4 L) at 273.15 K.
39
every 1 degree temperature rise, increases the volume with a
(1/273.15) X (22.4 L) at 273.15 K.
22.4 L + ((1/273.15) X (22.4 L) )
every 1 degree temperature decrease, decreases the volume with a
(1/273.15) X (22.4 L) at 273.15 K.
22.4 L – ((1/273.15) X (22.4 L) )
40
The existence of a finite coefficient of thermal expansion sets a limit on the
thermal contraction of the ideal gas;
22.4 L – ((1/273.15) X (22.4 L) X 273.15 ) = 0 volume
that is, since α = 1 / 273.15, then the fractional decrease in the volume of the
gas, per degree decrease in temperature, is 1/273.15 of the volume at 0° C
(22.4 L).
Thus, at – 273.15° C, the volume of the gas would be zero, and hence the limit
of temperature decrease, – 273.15° C, is the absolute zero of temperature.
41
THE EQUATION OF STATE OF AN IDEAL GAS
The pressure– volume relationship of a gas at constant temperature was determined
experimentally in 1660 by Robert Boyle, who found that, at constant T,
42
This is known as Boyle’
s law .
43
The relationship between V and T, which is known as Charles’ law, is that,
at constant pressure,
44
45
46
THE UNITS OF ENERGY AND WORK
The unit liter・atm occurring in the units of R is an energy term
Work is done when a force moves a body through a distance.
Work and energy have the dimensions F X distance .
Pressure is force per unit area; P = F/A, F = P X A, hence,
work and energy can have the dimensions:
Work = Pressure X area X distance, or
Work = Pressure X volume.
47
How can we convert Liter X atm to joules?
P = F/A
Joule
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Joule =Newton X Meter.
Newton: 1 kg. m /s2