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  • Materials Selection Lecture otes These otes is by oway a Replacement of Classroom Attendence !!!

    Dr. Saad B. H. Farid 5 * 1

    General References: 1- Engineering Materials, Properties and Selection

    Kenneth G. Budinski

    2- Engineering Materials Technology

    Bill Bolton

    3- Lecture notes by professors of international universities.

    1- All Exam Question are in English, Answers can be in Arabic, The

    student should aware of the scientific and engineering idioms.

    2- The student final degree depends on Exams and Other Activities,

    E.g., writing essays and reports; also, attending class lectures is of

    prime importance.

    The field of materials science and engineering is often defined by the

    interrelationship between four topicssynthesis and processing,

    structure and composition, properties, and performance.

    # What is the Responsibilities of Materials Engineer? 1- Phase -1 of design process Drawing the basic design.

    Phase -2 of design process Selection of Proper Materials, i.e. section of material according to many parameters e.g.

    Mechanical loads,

    Wear,

    Electrical insulation,

    Thermal properties, and

    Availability and cost.

    This includes;

    Selection of the proper manufacturing process or processes, All sums to what is called The Technological Root

    2- Proper choice (selecting) of substitute (alternative) materials when

    needed,

    3- Contributing and Evaluating Materials tests results,

    4- Studying and Composing Materials Data sheets before placing an order,

    5- Doing Research Activities to enhance materials performance.

    # What are the other contributions of the Materials Engineer?

    LLeeccttuurree 0011

  • Materials Selection Lecture otes These otes is by oway a Replacement of Classroom Attendence !!!

    Dr. Saad B. H. Farid 5 * 2

    Budinski Classification of Materials: -

    Engineering materials:

    Basically, they are of four types:-

    A. Metals: Elements with a valence of 1, 2 or 3. They are

    crystalline solids composed of atoms held together by a matrix

    of electrons. The Electron Gas that surrounds the Lattice of

    atomic nuclei is responsible for most of the properties.

    1. General properties: High electrical conductivity, high

    thermal conductivity, ductile and relatively high stiffness,

    toughness and strength. They are ready to machining,

    casting, forming, stamping and welding. Nevertheless,

    they are susceptible to corrosion.

    Materials

  • Materials Selection Lecture otes These otes is by oway a Replacement of Classroom Attendence !!!

    Dr. Saad B. H. Farid 5 * 3

    2. Further description: Engineering metals are generally

    Alloys. Alloys are metallic materials formed by mixing

    two or more elements, e.g.

    i. Mild steel Fe + C

    ii. Stainless steel Fe + C + Cr + Mn etc.

    iii. C improves Strength

    iv. Cr improves the corrosion resistance etc.

    3. Classification: of metals and alloys:

    i. Ferrous: Plain carbon steel, Alloy steel, Cast iron,

    ii. Nonferrous: Light Alloys (Al, Mg, Ti, Zn), Heavy

    Alloys (Cu, Pb, Ni), Refractory Metals (Mo, Ta,

    W), Precious metals (Au, Ag, Pt)

    4. Applications:

    i. Electrical wiring

    ii. Structures: buildings, bridges, etc.

    iii. Automobiles: body, chassis, springs, engine

    block, etc.

    iv. Airplanes: engine components, fuselage, landing

    gear assembly, etc.

    v. Trains: rails, engine components, body, wheels

    vi. Machine tools: drill bits, hammers, screwdrivers,

    saw blades, etc.

    vii. Magnets

    viii. Catalysts

    5. Examples:

    i. Pure metal elements (Cu, Fe, Zn, Ag, etc.)

    ii. Alloys (Cu-Sn=bronze, Cu-Zn=brass, Fe-C=steel,

    Pb-Sn=solder)

    iii. Intermetallic compounds (e.g. Ni3Al)

    ote

  • Materials Selection Lecture otes These otes is by oway a Replacement of Classroom Attendence !!!

    Dr. Saad B. H. Farid 5 * 4

    B. Ceramics: Inorganic, non-metallic crystalline compounds,

    usually oxides (SiO2, Al2O3, MgO, TiO2, BaO), Carbides

    (SiC), Nitrides (Si3N4), Borides (TiB2), Silicides (WSi2,

    MoSi2). Some literature includes glasses in the same category,

    however; glasses are amorphous (non-crystalline) compounds

    i.e. they possess short range order of atoms.

    1. General properties: Light weight, Hard, High strength,

    stronger in compression than tension, tend to be brittle,

    low electrical conductivity, High temperature resistance

    and corrosion resistance.

    2. Further description: Ceramics also includes ferrites

    (ZnFe2O4), semiconductors (ZnO, TiO2, CuO, SiC, AlN,

    BN, C, Si, Ge, SiGe), piezoelectric and ferroelectric

    ceramic (BaTiO3, PZT=PbZrTiO3) and superconducting

    ceramics (YBa2Cu3O7).

    3. Classification: of ceramics:

    i. Traditional Ceramics: Includes pottery, china,

    porcelain productsetc, these products utilizes

    natural ceramic ores.

    ii. Advanced Ceramics: Alumina, magnesia,

    Carbides, Nitrides, Borides, Silicides etc, they

    are synthetic materials, usually of better

    mechanical properties. Electronic ceramics falls in

    the same category.

    iii. Glass, Glass Ceramic and Vitro Ceramic: Glasses

    are essentially vitreous (amorphous, non

    crystalline), Glass ceramics are mostly re-

    crystallized from glassy medium and, Vitro

  • Materials Selection Lecture otes These otes is by oway a Replacement of Classroom Attendence !!!

    Dr. Saad B. H. Farid 5 * 5

    Ceramics have crystalline microstructure which are

    partially vitreous at the grain boundaries.

    4. Applications:

    i. Electrical insulators

    ii. Abrasives

    iii. Thermal insulation and coatings

    iv. Windows, television screens, optical fibers (glass)

    v. Corrosion resistant applications

    vi. Electrical devices: capacitors, varistors,

    transducers, etc.

    vii. Highways and roads (concrete)

    viii. Biocompatible coatings (fusion to bone)

    ix. Self-lubricating bearings

    x. Magnetic materials (audio/video tapes, hard

    disks, etc.)

    xi. Optical wave guides

    xii. Night-vision

    5. Examples of technical ceramics i. Barium titanate (often mixed with strontium

    titanate) displays ferroelectricity, meaning that its

    mechanical, electrical, and thermal responses are

    coupled to one another and also history-dependent.

    It is widely used in electromechanical transducers,

    ceramic capacitors, and data storage elements.

    ii. Bismuth strontium calcium copper oxide, a high-

    temperature superconductor

    iii. Boron carbide (B4C), which is used in ceramic

    plates in some personnel, helicopter and tank

    armor.

  • Materials Selection Lecture otes These otes is by oway a Replacement of Classroom Attendence !!!

    Dr. Saad B. H. Farid 5 * 6

    iv. Boron nitride is structurally isoelectronic to carbon

    and takes on similar physical forms: a graphite-like

    one used as a lubricant, and a diamond-like one

    used as an abrasive.

    v. Ferrite (Fe3O4), which is ferrimagnetic and is used

    in the magnetic cores of electrical transformers and

    magnetic core memory.

    vi. Lead zirconate titanate is another ferroelectric

    material.

    vii. Magnesium diboride (MgB2), which is an

    unconventional superconductor.

    viii. Sialons / Silicon Aluminium Oxynitrides, high

    strength, high thermal shock / chemical / wear

    resistance, low density ceramics used in non-

    ferrous molten metal handling, weld pins and the

    chemical industry.

    ix. Silicon carbide (SiC), which is used as a susceptor

    in microwave furnaces, a commonly used abrasive,

    and as a refractory material.

    x. Silicon nitride (Si3N4), which is used as an abrasive

    powder.

    xi. Steatite (MgSiO3), used as an electrical insulator.

    xii. Uranium oxide (UO2), used as fuel in nuclear

    reactors.

    xiii. Yttrium barium copper oxide (YBa2Cu3O7-x),

    another high temperature superconductor.

    xiv. Zinc oxide (ZnO), which is a semiconductor, and

    used in the construction of varistors.

  • Materials Selection Lecture otes These otes is by oway a Replacement of Classroom Attendence !!!

    Dr. Saad B. H. Farid 5 * 7

    xv. Zirconium dioxide (zirconia), its high oxygen ion

    conductivity recommends it for use in fuel cells. In

    another variant, metastable structures can impart

    transformation toughening for mechanical

    applications; most ceramic knife blades are made

    of this material.

    6. Semiconductors Applications and Examples

    i. Computer CPUs

    ii. Electrical components (transistors, diodes, etc.)

    iii. Solid-state lasers

    iv. Light-emitting diodes (LEDs)

    v. Flat panel displays

    vi. Solar cells

    vii. Radiation detectors

    viii. Microelectromechanical devices (MEMS)

    ix. Examples: Si, Ge, GaAs, and InSb

    C. Polymers: High molecular weight organic substance made up

    of a large number of repeat (monomer) units. Their properties

    are linked directly to their

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