Material Science

MENG 286 – Fall 2023

MATERIAL SCIENCE
MENG 286 – Fall 2023
 Material Science
MENG 286 – Fall 2023

Dr. Seyedalireza Razavi

Office: EE138
S.Razavi@emu.edu.tr
Required Text
Material Science
MENG 286 – Fall 2023

MATERIALS SCIENCE AND ENGINEERING: AN

INTRODUCTION, W.D. Callister, Jr. and D.G. Rethwisch, 8th
edition, John Wiley and Sons, Inc. (2010).

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Timetable
Material Science
MENG 286 – Fall 2023

08:30-09:20 MENG286(01) / CE 103

09:30-10:20 MENG286(01) / CE 103

10:30-11:20

11:30-12:20

12:30-13:20 MENG286(01) / CE 102

13:30-14:20 MENG286(01) / CE 102

14:30-15:20

15:30-16:20

16:30-17:20

17:30-18:20

18:30-19:20

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 Material Science
MENG 286 – Fall 2023

CHAPTER 1
Introduction
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Historical Perspective
Material Science
MENG 286 – Fall 2023

• What is materials science and why we should know about it?

• Materials influence our lives in every segments.
− Automobile, phones, refrigerators, TVs, computers, etc.
• > 10,000 different types materials have evolved with rather specialized characteristics to meet the needs of
our modern and complex society.
• In fact, historically, the development of civilized societies was tied to the level of material developments
(Stone Age, Bronze Age, Iron Age).

• Early material types were:

− Clay, stone, wood, skins, etc.
• Modern material types are:
− Steel, composites, semiconductors, plastics, glasses, fibers, etc.

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Material Science & Engineering
Material Science
MENG 286 – Fall 2023

• Are two different disciplines.

• Material science:
− investigates the relationships between structures and properties of materials.
• Material engineering:
− investigates the structural properties, designing the structures of a material to produce a desired set of
properties.

• The roles are different as well.

• Material scientists
− develop or synthesize new materials
• Material engineers
− create new products and systems using existing materials, or, to develop techniques for processing
materials.

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Material Science & Engineering
Material Science
MENG 286 – Fall 2023

• (Continue of previous slide…)

• Material engineers have the option of selecting a best material from, e.g., 1000 of
available ones. A selection is based on criteria, such as:
1. In-service conditions must be characterized, which dictates the find required properties.
− E.g., trade-off between strength vs. ductility
2. Deterioration of material properties during in-service operation.
− E.g., reduction in mechanical strength dur to exposure to elevated temperature or corrosive environment
3. Economics (the overriding consideration).
− E.g., the choice of cost vs. fabrication process, desired shape, finish, structure-properties relationships.

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Classification of Materials
Material Science
MENG 286 – Fall 2023

• Most engineering materials can be classified into one of three basic categories:
1. Metals
2. Ceramics
3. Polymers

• Their chemistries in addition to their mechanical and physical properties are different.
• In addition, there is a fourth category:
4. Composites

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 Classification of Materials
Material Science
MENG 286 – Fall 2023

Source:
Fundamentals of Modern Manufacturing
materials: processes and systems, M.P.
Groover, 5th edition, John Wiley & Sons Inc. (2007).

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Metals
Material Science
MENG 286 – Fall 2023

• Characterized by their metallic bonds.

• Metals are composed of one or more metallic elements (e.g., iron, aluminum, copper,
titanium, gold, nickel). And often also nonmetallic elements (e.g., carbon, nitrogen,
oxygen) in relatively small amounts.
• Strong, ductile, resistant to fracture
• High thermal & electrical conductivity (due to electrons’ mobility)
• Opaque, reflective

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Ceramics
Material Science
MENG 286 – Fall 2023

• Characterized by their Ionic bonding.

• Ceramics are compounds between metallic and nonmetallic elements;
• they are most frequently oxides, nitrides, and carbides.
− E.g., For example, common ceramic materials include aluminum oxide (or alumina, Al2O3), silicon
dioxide (or silica, SiO2), silicon carbide (SiC), silicon nitride (Si3N4).

• Two main classifications of ceramics are:

• Traditional ceramics —those composed mainly of clay and silica (e.g., porcelain), alumina.
− Alumina is “Aluminum oxide” which is a compound containing Aluminum (the chemical element). It is
much stronger with high temperature and corrosion resistance properties than its metallic counterpart
element, Al.
∙ Pottery and Tableware
∙ Brick and tile
∙ Refractories
∙ Abrasives

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Ceramics
Material Science
MENG 286 – Fall 2023

• Characterized by their Ionic bonding.

• Ceramics are compounds between metallic and nonmetallic elements;
• they are most frequently oxides, nitrides, and carbides.
− E.g., For example, common ceramic materials include aluminum oxide (or alumina, Al2O3), silicon
dioxide (or silica, SiO2), silicon carbide (SiC), silicon nitride (Si3N4).

• Two main classifications of ceramics are:

• Traditional ceramics —those composed mainly of clay and silica (e.g., porcelain), alumina.
− Alumina is “Aluminum oxide” which is a compound containing Aluminum (the chemical element). It is
much stronger with high temperature and corrosion resistance properties than its metallic counterpart
element, Al.
• New ceramics —developed synthetically based on oxides, carbides, nitrides, etc.,
− Have better mechanical or physical properties than traditional ceramics.
Nitride Carbide
∙ Spark plug barrels
∙ Engineering components
∙ brick
∙ Electrical insulators and electronic components
Si-Carbide 13
Alumina
Ceramics Properties
Material Science
MENG 286 – Fall 2023

• Mechanical properties
• Stiff
• Strong–Stiffness and strengths comparable to those of the metals
• High hardness (resistant to harsh environments)
• Extremely brittle (highly susceptible to fracture)
• Light-weight
• High thermal and electrical resistances

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Polymers
Material Science
MENG 286 – Fall 2023

• Characterized by their Covalent bonding → sharing e’s.

• Defined as a compound consisting of long-chain molecules, each molecule made up of
repeating units connected together
• There may be thousands, even millions of units in a single polymer molecule.
• The word polymer is derived from the Greek words poly, meaning many, and mer, meaning part.
• Most polymers are based on carbon and are therefore considered organic chemicals.

• Examples:
− Polyethylene (PE)
− Nylon
− Poly(vinyl chloride) (PVC)
− Polycarbonate (PC)
− Polystyrene (PS)
− Silicone rubber

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Polymers Properties
Material Science
MENG 286 – Fall 2023

• Covalent bonding → Sharing of e’s

• Soft, ductile, low strength, low density
• Thermal & electrical insulators
• Optically translucent or transparent.
• Chemically inert and unreactive
• Sensitive to temperature changes

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Composites
Material Science
MENG 286 – Fall 2023

• A materials system composed of two or more distinct phases whose combination produces
aggregate properties different from those of its constituents
• Examples:
− Cemented carbides (WC with Co binder)
− Plastic molding compounds with fillers
− Rubber mixed with carbon black
− Wood (a natural composite as distinguished from a synthesized composite)

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Why Composites Are Important?
Material Science
MENG 286 – Fall 2023

• Pros
• Composites can be very strong and stiff, yet very light in weight
• Strength-to-weight and stiffness-to-weight ratios are several times greater than steel or aluminum
• Fatigue properties are generally better than for common engineering metals
• Toughness is often greater
• Possible to achieve combinations of properties not attainable with metals, ceramics, or polymers alone

• Cons
• Properties of many important composites are anisotropic
• May be an advantage or a disadvantage
• Many polymer-based composites are subject to attack by chemicals or solvents
• Just as the polymers themselves are susceptible
• Composite materials are generally expensive
• Manufacturing methods for shaping composite materials are often slow and costly

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Components And Classifications of Composites
Material Science
MENG 286 – Fall 2023

• Most composite materials consist of two phases:

• Primary phase –forms the matrix within which the secondary phase is imbedded.
− Provides the bulk form of the part or product made of the composite material.
− Holds the imbedded phase in place, usually enclosing and often concealing it.
− When a load is applied, the matrix shares the load with the secondary phase, in some cases deforming so
that the stress is essentially born by the reinforcing agent.
∙ Examples: epoxy in which carbon fiber reinforcement agent is embedded.
• Secondary phase - imbedded phase sometimes referred to as a reinforcing agent, because it usually
strengthens the composite material. The reinforcing phase may be in the form of fibers, particles, or various
other geometries.
− Function is to reinforce the primary phase
− Reinforcing phase (imbedded in the matrix) is most commonly one of the following shapes: fibers,
particles, or flakes
− Also, secondary phase can take the form of an infiltrated phase in a skeletal or porous matrix
∙ Example: a powder metallurgy part infiltrated with polymer.

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Classifications of Composites
Material Science
MENG 286 – Fall 2023

• Classifications of composites can be:

1. Metal Matrix Composites (MMCs) - mixtures of ceramics and metals, such as cemented
carbides and other cermets
2. Ceramic Matrix Composites (CMCs) - Al2O3 and SiC imbedded with fibers to improve
properties
3. Polymer Matrix Composites (PMCs) - polymer resins imbedded with filler or reinforcing
agent
− Examples: epoxy and polyester with fiber reinforcement, and phenolic with powders

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Ashby Charts
Material Science
MENG 286 – Fall 2023

• Also called:
• Materials Properties Charts
• Materials Selection Charts
• Bubble Charts, or
• Ashby Charts

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Advanced Materials
Material Science
MENG 286 – Fall 2023

• Materials that are utilized in high-tech applications.

• High Technology: Products or devices that operates or functions using relatively intricate and sophisticated
principles including.
− Electronic equipment (cell phones, DVD players, etc.), computers, fiber-optic systems, high-energy
density batteries, energy-conversion systems, and aircraft.

• Advanced materials include

• Semiconductors, biomaterials, smart materials, nanomaterials –materials of the future.
− Materials that are used for lasers, batteries, magnetic information storage, liquid crystal displays (LCDs),
and fiber optics.

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Advanced Materials
Material Science
MENG 286 – Fall 2023

• Semiconductors
• Have electrical conductivities intermediate between conductors and insulators.
− Semiconductors have made possible the advent of integrated circuitry that has totally revolutionized the
electronics and computer industries (not to mention our lives) over the past four decades.

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Advanced Materials
Material Science
MENG 286 – Fall 2023

• Biomaterials
• nonviable (i.e., nonliving) materials that are implanted into the body, so that they function in a reliable, safe,
and physiologically satisfactory manner, while interacting with living tissue.
− Application examples include joint (e.g., hip, knee) and heart valve replacements, vascular (blood vessel)
grafts, fracture-fixation devices, dental restorations, and generation of new organ tissues.

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Advanced Materials
Material Science
MENG 286 – Fall 2023

• Smart Materials
• these materials are able to sense changes in their environment and then respond to these changes in
predetermined manners—traits that are also found in living organisms.
− Sensors & Actuators (i.e., detecting signals and responding adaptively)

• Four types of smart materials used for actuators:

• Shape-memory alloys
− Metals that, after having been deformed, revert to their original shape when temperature is changed
• Piezoelectric ceramics
− Expand and contract in response to an applied electric field (or voltage); conversely, they also generate
an electric field when their dimensions are altered
• Magnetostrictive materials
− Analogous to that of the piezoelectric, except that they are responsive to magnetic fieldS
• Electrorheological/magnetorheological fluids
− Liquids that experience dramatic changes in viscosity upon the application of electric and magnetic
fields, respectively

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Advanced Materials
Material Science
MENG 286 – Fall 2023

• Nanomaterials
• One new material with fascinating properties and technological applications.
− Can be out of any four basic types –metals, ceramics, polymers, or composites.
• However, unlike other materials, they are distinguished by their size rather than their chemistries.
− I.e., nano = the size is in the other of 10-9 (as a rule <100 nanometers (nm; equivalent to the diameter of
approximately 500 atoms)).
• Some of the physical and chemical characteristics exhibited by matter may experience dramatic changes as
particle size approaches atomic dimensions:
− for example, materials that are opaque in the macroscopic domain may become transparent on the
nanoscale;
− some solids become liquids,
− chemically stable materials become combustible, and
− electrical insulators become conductors

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The Material Selection Process
Material Science
MENG 286 – Fall 2023

1. Pick application
• Determine required properties
− Properties: mechanical, electrical, thermal, magnetic, optical, deteriorative

2. Properties
• Identify candidate material(s)
− Materials: structure, composition

3. Material
• Identify required Processing
− Processing changes structure and overall shape.
− Examples: casting, sintering, vapor deposition, doping, forming, joining, annealing.

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Ashby Charts – i
Material Science
MENG 286 – Fall 2023

Bar chart of room-temperature density values for various metals, ceramics, polymers, and
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composite materials.
Ashby Charts – ii
Material Science
MENG 286 – Fall 2023

Bar chart of room-temperature stiffness (i.e., elastic modulus) values for various metals,
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ceramics, polymers, and composite materials.
Ashby Charts – iii
Material Science
MENG 286 – Fall 2023

Bar chart of room-temperature resistance to fracture (i.e., fracture toughness) for various
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metals, ceramics, polymers, and composite materials.
Ashby Charts – iv
Material Science
MENG 286 – Fall 2023

Bar chart of room-temperature electrical conductivity ranges for metals, ceramics, polymers,
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and semiconducting materials.