EMA5001 Physical Properties of Materials...Introduction (week 1) Diffusion phenomena and theory (week ~2-5) Interfacial phenomena (week ~6-8) Solidification and nucleation (week ~9,

EMA5001

Physical Properties of Materials

Lecture 0 Introduction

Prof. Zhe Cheng

Mechanical & Materials Engineering

Florida International University

EMA 5001 Physical Properties of Materials Zhe Cheng (2016) 0 Course Information

Course Information & Policy

Zhe Cheng

305-348-1973; [email protected]; Office: EC3441

Textbook & Other Course Materials

Phase Transformations in Metals and Alloys, D A Porter, K E Easterling, and M Y

Sherif, 3rd edition, CRC Press, (2008). ISBN 978-1-4200-6210-6 (0)

Policy

Attendance required; Turn off cell phone/pagers during class

Students can discuss homework problems, but must independently finish it

Grade discrepancies – resolve in the same day

Homework will NOT be collected or graded; solution will be provided

Accommodate “make-up” quiz, tests, or delayed term paper if proven medical

necessity

Accommodate disability (http://drc.fiu.edu/) and religious holidays

NO cheating or plagiarizing in ANY form (Check with me if questions)

− No excuses will be accepted

− Will be reported and handled according to FIU policy

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mailto:[email protected]

http://drc.fiu.edu/


More about Dr. Zhe Cheng

Education & Experiences:

PhD in Materials Science & Engineering, Georgia Tech, 2008

Research scientist, DuPont, Wilmington DE, 2008-2013

Research group website https://ac.fiu.edu

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Exams & Grading

Homework (10%)

Term Paper (30%)

Mid-term Exam (30%)

Final Exam (30%)

Grading Scale

A: >=90; A-: 87-89.9;

B+: 84-86.9; B: 80-73.9; B-: 77-79.9;

C+: 74-76.9; C: 67-73.9;

D: 60-66.9.

F: <60

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Term Paper Guidelines

Deadlines & Submission (Email submission only)

Early March: 1st draft

Early April: 2nd draft

Late April: Final submission

− Term paper plus major references

− A separate document answering the reviewers’ question/comments (for 2nd draft and final

version)

Format of Main Document

Times New Roman, 12 point (Figures/table may use smaller font), single space,

1 inch margin on all sides, print double-sided

4 pages maximum excluding references

Grading

Missing deadline: zero

4 points for 1st draft; 4 points for 2nd draft; 12 points for final term paper

5 points for quality of “review” provided to other students’ paper (2 reviews)

5 points for answering/rebutting “peer review” questions/comments

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Term Paper Content

Guidelines on Term Paper Content

A detailed critique of at least two or more research papers (must be by different

research groups) on a single problem/topic involving kinetics and/or phase

transformation in materials in a specific area of interest to you

It should have most of the following (but NOT necessary all)

− Introduction

− Background

− Analysis/critiques on

• Significance and why you are interested

• Assumptions/Methodology/Mathematical derivation/Argument/Logic

• Experimental design, data collection and analysis

• Consistency and/or contradictions between different studies

• Unanswered questions

• Your own analysis/proposed research method or data analysis

− Recommendations for future work

− Conclusions

− References

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Course Objective & Outcome

Objectives

Introduce graduate-level principles about kinetics and phase transformation of

engineering materials involving phenomena including diffusion, movement of

interfaces, solidification, nucleation and growth, phase transformation and kinetics

Provide graduate-level training in critical thinking, mathematical analysis, and

written communication skills focusing on problems of interests involving kinetics

and phase transformation of engineering materials

Related MME Program Outcomes

a) Ability to apply knowledge of mathematics, science, and engineering

e) Ability to identify, formulate, and solve engineering problems

g) Ability to communicate effectively

i) Recognition of the need for, and a ability to engage in life-long learning

k) Ability to use the techniques, skills and modern engineering science necessary

for engineering

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Thermodynamics

(Write down concepts remembered, 3 min)

Basic Concepts from past

…

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Thermodynamics

Basic Concepts from past

1st law & 2nd law

Enthalpy, Entropy, Free energy, Basic relationships of thermodynamic functions

Temperature & pressure effects

Equilibrium

Defects in solids

Solutions

− Partial molar quantities

− Chemical potential

− Activity and activity coefficient

− Mixing, Ideal solution & Regular solution

Phase diagrams and phase rule

Gas solid reactions & Ellingham diagrams

Surface & interfaces

Electrochemistry

…

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Kinetics & Phase Transformation

Thermodynamics

Equilibrium states

Possibility & the direction of

transformation between states

Questions:

− Do things ALWAYS reach thermodynamically most favorable states? (2 min)

Kinetics & Phase Transformation

Rate and dependence of rate on different factors

− Condition (temp, time, atmosphere, etc.)

− Composition

− …

How - changes in

− Composition

− Crystal structure

− Morphology/microstructure

− …

Depend highly on specific systems – Be careful with any generalization

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Initial state

Final state

G

G = G’ - G0

G0

G’

Final state

G

G = G’ - G0

G’ = G’’ - G0

G0

G’

Metastable state G’’


Example/Practical Problem for Kinetics (1)

Steel containing 0.4 wt.% of C

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Modified from slide for Materials Science & Engineering: An Introduction by McCalister 8ed published by Wiley



Steel containing 0.4 wt.% of C

Processing controls microstructure which determines hardness to a large extent

Kinetics and phase transformation in processing influence microstructure and

resulting materials properties

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Data obtained from Figs. 10.30(a)

and 10.32 with 4 wt% C composition,

and from Fig. 11.14 and associated

discussion, Callister & Rethwisch 8e.

Micrographs adapted from (a) Fig.

10.19; (b) Fig. 9.30;(c) Fig. 10.33;

and (d) Fig. 10.21, Callister &

Rethwisch 8e.

Hard

ness (

BH

N)

Cooling Rate (ºC/s)

100

2 00

3 00

4 00

5 00

6 00

0.01 0.1 1 10 100 1000

(d)

30 mm (c)

4 mm

(b)

30 mm

(a)

30 mm

Modified from slide for Materials Science & Engineering: An Introduction by McCalister 8ed published by Wiley

Spheroidite

Martensite

Pearlite

Tempered Martensite



B4C synthesis

Underlying reaction 2B2O3 + 7C = B4C + 6CO

How to best control microstructure/micromophology for the reaction/phase

transformation process?

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1450 oC/3 hour, normal tube furnace Pure B4C with structural non-uniformity

P. Foroughi & Z. Cheng, Advances in Ceramic Armor, 2015, p. 51-62

1750 oC/3 min, microtube reactor Pure B4C, with narrow size distribution

P. Foroughi & Z. Cheng, unpublished results



B4C synthesis, continued

Questions:

When will reaction not proceed?

Reaction temperature goes higher,

what happens?

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1900°C/1 sec, graphite tube furnace Pure B4C with uniform nano-size powder

Weimer J Am Ceram Soc, 1992,

1150°C/24 hour, normal tube furnace Trace B4C with mostly unreacted materials

P. Foroughi & Z. Cheng, Advances in Ceramic Armor, 2015, p. 51-62

Calculated standard free energy change for 2B2O3 + 7C = B4C + 6CO


Topics & Planned Schedule

Introduction (week 1)

Diffusion phenomena and theory (week ~2-5)

Interfacial phenomena (week ~6-8)

Solidification and nucleation (week ~9, 11)

Phase transformation (week ~12-14)

Kinetic models in phase transformation (week ~16)

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Write Down Practical Examples

Showing The followings

Diffusion

Interfaces

Solidification

Diffusional transformation

Diffusionless transformation

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Many Examples for Kinetics &

Phase Transformation

Diffusion

Emitter formation for Si chip & solar cells

Li ion releasing from/Insertion into cathodes of lithium ion battery

Oxygen vacancy diffusion for solid oxide fuel cells

H transport through Pd membrane for hydrogen separation

Interfaces

Grain boundaries in silicon solar cell versus CIGS solar cell

Solidification

Casting of Si ingot

Diffusional transformation

Nucleation and growth

Spinodal decomposition

Diffusionless transformation

Martensite transformation in iron and steel for hardening

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Major Types of Materials in Many Applications!

Documents

EMA5001 Physical Properties of Materials...Introduction (week 1) Diffusion phenomena and theory (week ~2-5) Interfacial phenomena (week ~6-8) Solidification and nucleation (week ~9,