Chapter 1-2 Atomic Bonding Structure of Crystalline Solids PDF

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Warning: TT: undefined function: 32 Course Timetable for September Course Outcomes (CO)Atthe endof the course, the students shouldbe able to:Analyse the processes of diffusion, dislocation,phase diagrams and phase transformation ofmaterials in relations to their materials'mechanical properties.Expla...

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Introduction To Material Science

Course Timetable for September 2019

UTP-IMS_Sept 2019©

11 September 2019

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Introduction To Material Science

Course Outcomes (CO) At the end of the course, the students should be able to:

Explain the microstructure-property relationship of various materials based on their crystalline structures and defects present.

1

2

UTP-IMS_Sept 2019©

Analyse the processes of diffusion, dislocation, phase diagrams and phase transformation of materials in relations to their materials' mechanical properties.

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Introducti

Mechanical Engineering Programme Outcomes (PO) Mechanical Engineering Programme Outcomes (PO) PO 1

Apply knowledge of mathematics, science, engineering fundamentals and specialized engineering in solving complex engineering problems.

PO 2

Identify research literature, investigate, analyze, evaluate and formulate solutions to complex Mechanical Engineering problems reaching substantiated conclusion using first principles of mathematics, natural sciences and engineering sciences.

PO 3

Undertake holistic design and development of complex Mechanical Engineering problems and design systems, components or processes that meet specified needs with appropriate consideration for public health and safety, cultural, societal, and environmental considerations.

PO 4

Perform investigation into complex Mechanical Engineering using research based knowledge including design of experiments, analysis and interpretation of data, and synthesis of information to provide valid conclusions.

PO 5

Create, select and apply appropriate techniques, resources, and modern engineering and IT tools, including prediction and modeling, to complex engineering activities, with an understanding of the limitations.

PO 6

Apply reasoning informed by contextual knowledge to assess societal, health, safety, legal and cultural issues and the consequent responsibilities relevant to professional engineering practice.

PO 7

Understand the impact of professional engineering solutions in societal and environmental contexts and demonstrate knowledge of and need for sustainable development.

P0 8

Internalize and practice professional ethical principles with commitment to norms of engineering practices.

PO 9

Communicate effectively on complex engineering activities with the engineering community and with society at large.

PO10

Function effectively in multi-disciplinary engineering as an individual and in a group with the capacity to be a leader.

PO11

Recognize the need to undertake life-long learning and possess the capacity to adapt to technological changes.

PO12

Demonstrate knowledge and understanding in project management, business acumen and entrepreneurship in multidisciplinary environments.

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Introduction To Material Science

Mapping of C PO

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Introduction To Material Science

September 2019 Course Plan Course Code & Name Lecturers Assessment

MEB1012 Introduction to Material Science Dr Norlin Nosbi / Assoc. Prof. Dr. Othman Mamat Coursework - 50% (Quizzes, Tests, Assignments) Final Exam - 50% By the end of the course, the students should be able to:

(Course Learning Outcomes, CLO)

1.Explain the microstructure-property relationship of various materials based on their crystalline structures and defects present. 2.Analyse the processes of diffusion, dislocation, phase diagrams and phase transformation of materials in relations to their materials' mechanical properties.

Course Sinopsis

UTP-IMS_Sept 2019©

This course provides the fundamentals in understanding the structureproperty relationship of materials which is relevant to all engineering disciplines. The knowledge is crucial in order to be able to select the correct material for a specific application, to understand the deterioration of material properties during service operation and to create new materials with desirable properties.

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Introduction To Material Science

Course Plan for MEB1012 September 2019 Cour Course se sew wor ork: k: 50% (Quizz (Quizzes, es, Ex Exam am 1, Ex Exam am 2) Final Ex Exam am am:: 50%

1

2

4

3

Introduction to Materials and Atomic Bonding ฀ Definition and History of Materials ฀ Importance of Materials in Modern World, Review of Atomic Bonding WEEK 1: 02-06/09/19

The structure of crystalline solids ฀ Crystal Structures, Crystallographic Direction and Plane ฀ Crystalline and Non-crystalline Materials WEEK 2-3: 09-20/09/19

UTP-IMS_Sept 2019©

Imperfections in Solids ฀ Point and line defects ฀ Miscellaneous Imperfections ฀ Grain Size Determination WEEK 4-5: 23/9-04/10/19

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Mechanical properties of materials ฀ Elastic and Plastic Deformation, Stress-strain Behaviour ฀ Stress and Strain, Ductile vs Brittle, ฀ Compressive, Shear and Torsional Deformation, Hardness, Safety Factors WEEK 8-9: 21/10-01/11/19

Diffusion Diffusion Mechanism Steady-state and Non-steady-state Diffusion ฀ Factors affecting Diffusion WEEK 6-7: 07-18/09/19 EXAM 1: Friday,11/10/19 (5-7PM) HALL BLOCK B (near sport complex)

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7

REVISION WEEK 12: 18- 22/11/19

Phase diagrams for Metallic Systems and Phase Transformations ฀ Solubility Limits, Phase and Microstructure, Phase Equilibrium Diagram ฀ Binary Isomorphous and Binary Eutectic Systems, Lever Rule, The Iron-Carbon System ฀ Isothermal Transformation Diagrams WEEK 11-12: 11 – 18/11/19

Dislocations & Strengthening Mechanisms ฀ Basic Concepts of Dislocation ฀ Slip Systems, Solid-solution Hardening ฀ Strain Hardening WEEK 10: 04-08/11/19 EXAM 2: Thursday,31/10/19 (5-7PM) TEST ROOM BLOCK N

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Introduction To Material Science

WHY STUDY Material Science?

Properties of Material Selection of Material

❖

❖ r Mt



L

❖ UTP-IMS_Sept 2019©

Basic to understand the structure, properties and processing of materials Material science provides engineers and scientists with the knowledge required to ❖ Select appropriate materials; ❖ Design materials appropriate for specific applications; ❖ Use materials appropriately, efficiently, and safely; ❖ Dispose of these materials after their useful life. The only way to meet the requirement of current and future technology 11 September 2019

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Introduction To Material Science 1. Introduction to Materials and Atomic Bonding

1.1 Classification of Materials Metals: ➢Strong, ductile ➢High thermal & electrical conductivity ➢Opaque, reflective.

Ste Steel-cor el-cor el-cord d ti tirres

Polymer lymers s/plastics /plastics: Covalent bonding → sharing of e’s ➢Soft, ductile, low strength, low density ➢Thermal & electrical insulators ➢Optically translucent or transparent. Polymer

UTP-IMS_Sept 2019©

Metals and alloy

Wirereinforced cement

Hybrid Materials @Composites Ce Cerramic an and d gla glass ss GF GFRP RP

Ce Cerramics amics: ionic bonding ➢compounds of metallic & nonmetallic elements (oxides, carbides, nitrides, sulfides) ➢Brittle, glassy ➢Non-conducting (insulators) 11 September 2019

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Introduction To Material Science

STRUCTURE-PROPERTY RELATIONSHIP

Polymers

Metals

PROPERTIES

STRUCTURE STR UCTURE

Ceramics Different atomic arrangement results in different properties. UTP-IMS_Sept 2019©

Ceramics

Polymers

PROCESSING

Metals 11 September 2019

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Introduction To Material Science

STRUCTURE-PROPERTY RELATIONSHIP- An Example

Transmittance: (optical property) Aluminum oxide may be transparent, translucent, or opaque depending on the material structure.

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Introduction To Material Science

H Li

Be

Na

Mg

K

Ca

Rb

Sr

Cs

Ba

Fr

Ra

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inert gases

THE PERIODIC TABLE

accept 1e-

accept 2e-

• Columns: Similar Valence Structure

give up 3e-

give up 2e-

give up 1e-

1. Introduction to Materials and Atomic Bonding

He O

F

Ne

S

Cl

Ar

Sc

Se

Br

Kr

Y

Te

I

Xe

Po

At

Rn

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Introduction To Material Science

1. Introduction to Materials and Atomic Bonding

ELECTONEGATIVITY

✓ Ranges from 0.7 to 4.0 ✓ Large values: high tendency to acquire electrons

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Introduction To Material Science

1. Introduction to Materials and Atomic Bonding

ATOMIC BONDING IN SOLIDS

The forces of attraction that hold atoms together are called chemical bonds which can be divided into 2 categories : ATOMIC BONDING IN SOLIDS

Covalent Bonding

UTP-IMS_Sept 2019©

Primary

Secondary

Interatomic Bonding

Interatomic Bonding

Ionic Bonding

Metallic Bonding

Van der Waals

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Introduction To Material Science

1. Introduction to Materials and Atomic Bonding

IONIC BONDING

✓ Often found in compounds composed of electropositive elements (metals) and electronegative elements (nonmetals) ✓ Electron are transferred to form a bond ✓ Large difference in electronegativity required Ionic bond : metal

+

donates electrons

nonmetal accepts electrons

*Dissimilar electronegativities E.g. MgO Mg 1s2 2s2 2p6 3 s2 Mg2+ 1s2 2 s 2 2p6 [Ne]

UTP-IMS_Sept 2019©

O

1s2 2s 2 2p4 [Ne] 3s2

O2- 1 s2 2s2 2 p6 [Ne]

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Introduction To Material Science

1. Introduction to Materials and Atomic Bonding

• Properties : ✓ Solid at room temperature (made of ions) ✓ High melting and boiling points ✓ Hard and brittle ✓ Poor conductors of electricity in solid state ✓ Good conductor in solution or when molten

EXAMPLE OF IONIC BONDING

NaCl MgO CaF2 CsCl

H 2.1 Li 1.0

Be 1.5

Na 0.9

Mg 1.2

K 0.8

Ca 1.0

Rb 0.8

O F 3.5 4.0

Ne -

Cl 3.0

Ar -

Br 2.8

Kr -

Sr 1.0

I 2.5

Xe -

Cs 0.7

Ba 0.9

At 2.2

Rn -

Fr 0.7

Ra 0.9

Ti 1.5

Cr 1.6

Give up electrons UTP-IMS_Sept 2019©

He -

Fe 1.8

Ni 1.8

Zn 1.8

As 2.0

Acquire electrons

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Introduction To Material Science

1. Introduction to Materials and Atomic Bonding

COVALENT BONDING

❑ Similar electronegativity  share electrons ❑ Bonds determined by valence – s & p orbitals dominate bonding ❑ Electrons are shared to form a bond Properties: ➢ Gases, liquids, or solids (made of molecules) ➢ Poor electrical conductors in all phases ➢ Variable ( hard , strong, melting temperature, boiling point) Often found in: 1. Nonmetallic elemental molecules (H₂, Cl₂, F₂, etc.) 2. Molecule containing dissimilar atoms (CH₄,H₂O, HNO₃ and HF) 3. Molecules with metals and nonmetals such as aluminum phosphide (AlP) 4. Elemental solid (diamond, silicon, germanium) 5. Other solid compounds composed of elements that are located on the right hand side of the periodic table (gallium arsenide - GaAs, indium antimonide InSb and silicone carbide - SiC). UTP-IMS_Sept 2019©

Example: CH4 (Electronegativities

are comparable)

CH 4

H

H

C H

C: has 4 valence e- , needs 4 more shared electrons from carbon atom

H H: has 1 valence e-, needs 1 more shared electrons from hydrogen atoms

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Introduction To Material Science

EXAMPLE OF COVALENT BONDING

Often found in: 1. Nonmetallic elemental molecules (H₂, Cl₂, F₂, etc) 2. Molecule containing dissimilar atoms (CH₄,H₂O, HNO₃ and HF) 3. Molecules with metals and nonmetals such as aluminum phosphide (AlP) 4. Elemental solid (diamond, silicon, germanium) 5. Other solid compounds composed of elements that are located on the right hand side of the periodic table (gallium arsenide - GaAs, indium antimonide - InSb and silicone carbide - SiC). UTP-IMS_Sept 2019©

H2O

H2

column IVA

1. Introduction to Materials and Atomic Bonding

C(diamond) H 2.1 Li 1.0 Na 0.9 K 0.8

SiC

Be 1.5

Rb 0.8

Sr 1.0

Cs 0.7

Ba 0.9

Fr 0.7

Ra 0.9

He O 2.0

C 2.5 Si 1.8

Mg 1.2 Ca 1.0

F2

Ti 1.5

Cr 1.6

Fe 1.8

Ni 1.8

Zn 1.8

Ga 1.6

Ge 1.8

As 2.0

Sn 1.8 Pb 1.8

F 4.0 Cl 3.0

Ne -

Br 2.8

Kr -

I 2.5

Xe -

At 2.2

Rn -

Cl2

Ar -

GaAs

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Introduction To Material Science

1. Introduction to Materials and Atomic Bonding

METALLIC BONDING

➢ Occur when some electrons in the valence shell separate from their atoms and exist in a cloud surrounding all the positively charged atoms. ➢ The valence electron form a ‘sea of electron’. ➢ Found for group IA and IIA elements. ➢ Found for all elemental metals and its alloy

➢ Arises from a sea of donated valence electrons (1, 2, or 3 from each atom) ➢ Primary bond for metals and their alloys Properties:

❑ Good electrical conductivity ❑ Good heat conductivity ❑ Ductile ❑ Opaque

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Introduction To Material Science

1. Introduction to Materials and Atomic Bonding

SECONDARY BONDING asymmetric electron clouds

❑ Arises from interaction between dipoles ❑ Three bonding mechanism: (1) Fluctuating Induced Dipole Bonds Eg: Inert gases, symmetric molecules (H2, Cl2)

(2) Polar molecule-Induced Dipole Bonds Asymmetrical molecules such as HCl, HF

+

+

-

-

secondary bonding secondary bonding

Adapted from Fig. 2.13, Callister & Rethwisch 8e.

+

-

eg: H 2 H2

H H

H2 H H

secondary bonding

+

-

H Cl

secondary bonding

H Cl

liquid HCl (3) Permanent Dipole Bonds Hydrogen bonding, Between molecules

polyvinyl chloride

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Introduction To Material Science

1. Introduction to Materials and Atomic Bonding

Name:

ID:

Example #2 Specify the type of atomic bonding for each of the following materials: a. Methane (CH4) b. Magnesium oxide (MgO) c. Tungsten (W) d. Graphite e. Sodium chloride (NaCl)

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Introduction To Material Science

1. Introduction to Materials and Atomic Bonding

CONCL CLUSION CON CL USION

▪The major classes of materials include metals, polymers, ceramics and composites, each with distinctive properties. ▪ The structure of materials determine their properties. Properties can be changed during processing due to the change in the structure. ▪ In choosing the most suitable material for a specific application, various aspects need to be considered: the desirable properties, environmental impact, cost, safety, performance, etc. You should be able to: Differentiate between primary and secondary bonding and provide example of materials for each type. Predict the type of bonding based on the atoms electronegativity values.

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Introduction To Material Science

2. The Structure of Crystalline Solid Learning Outcomes Outcomes: At the end of the chapter, the students should be able to:

1

To describe the atomic arrangement for crystalline and non crystalline materials.

2

To draw unit cells for face-centered cubic (FCC), body centered cubic (BCC) and hexagonal close-packed (HCP) crystal structures

3

To derive the relationship between unit cell edge length and atomic radius, for FCC and BCC crystal structures

4

To compute the densities for metals having FCC and BCC crystal structures given their unit cell dimensions

Students will be assessed using Bloom’s Taxonomy: 1. Cognitive/Knowledge 2. Affective/Attitude

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Introduction To Material Science

FUNDAMENTAL CONCEPT : Classification of solid materials ✓ Atoms pack in periodic, 3D arrays ✓ Typical of: ❑ metals ❑ many ceramics ❑ some polymers

SOLIDS MATERIALS

✓ Atoms have no periodic packing ✓ Occurs for: ❑ complex structures ❑ rapid cooling

Crystalline Material Non-crsytalline material (Amorphous) Poly-crystal

Single crystal Si Oxygen

➢ Completely ordered ➢ In segments Non-crsytalline SiO2 A single crystal solid is a material in which the crystal lattice of the entire sample is continuous and unbroken to the edges of the sample. UTP-IMS_Sept 2019©

"Amorphous" = Non-crystalline

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Introduction To Material Science 2. The Structure of Crystalline Solid

CRYSTAL STRUCTURE Lattice The three dimensional array formed by the unit cells of a crystal is called lattice

+

Unit Cell - When a solid has a crystalline structure, the atoms are arranged in repeating structures called Unit Cells. The Unit Cell is the sm...