Engineering Materials PH:301 2006-2007

1. Engineering MaterialsPH:3012006-2007

2. The course in brief • Offered to: 3rd Semester B.Tech students of CSE, IT and ECE • Course coordinators: Dr. A. Pathak (anirban.pathak@jiit.ac.in), Dr. R. K. Dwivedi(rk.dwivedi@jiit.ac.in), & Dr. Amit Verma (amit.verma@jiit.ac.in) • Number of Credit: 4 (3 1 0) • Evaluation Criteria: End semester exam of 50 marks, two minors of 15 marks each and 20 marks for continual assessments in classes & tutorials (Test, Assignments).

3. Books • “ Solid State Physics” -- C. Kittal • “ Solid State Physics” -- S.O.Pillai • “Material Science and Engineering an Introduction” -- W.D. Callister Jr. • “ Material Science and Metallurgy” -- O.P.Khanna. • “Optical fiber Communication” – J. Senior • “Elements of Material Science and Enginnering” -- Lawrence H Van Vlack

4. What do engineers do? • Engineer’s adapt materials and energy for society need. Lawrence H Van Vlack in his famous book Elements of Material Science and Engineering • Materials and their properties are important for any discipline of Engineering. • Particular disciplines have interest in particular properties and particular kind of materials. • In this course we will bother about those properties which are used by ECE, CSE and IT engineers.

5. What modules will be taught • Dielectric materials • Magnetic materials • Polymers and Ceramics • Super-conductivity • Optical Fiber and Laser Communication • Nuclear Materials • Display Devices ***Notable exception, we will not teach Semiconductor materials******

6. Let us understand the importance of these module through some examples Examples: • Low k dielectric in VLSI • Magnetic materials for data storage • Display devices in your mobile to your laptop • As you call your parents the message goes through optical fiber 5. Blue ray disk

7. Exercises to convince you the importance • Find Five most advanced application of engineering science in your discipline which is already implemented and find out how material science played an important role in implementation of that. • Find out any two application of engineering science in your discipline which is already implemented and material science has not played an important role in implementation of that.

8. History of materialsorHistory of civilizationor History of Technology • 4000BC the glazing technique is developed (early use of metals) • Copper smelted from ore was developed in 4000BC ⇒knives and agricultural tools • 3000 BC Fire hardened clay (ceramics) ⇒This was a great discovery for early man and we guess they had GOD like feeling after learning the trick to change the nature of the material by changing it from clay to stone.

9. History of materialsorHistory of civilizationor History of Technology • 3000 BC Bronzes and other alloys of copper • 2600 BC shaping and joining of precious metals like Gold and silver.

10. What are materials? • That's easy. Look around. What do you see? Materials are everywhere! • The clothes we wear are made from a variety of materials. • Our home is made of materials - mostly manufactured. The glass in the windows, the ceramic dinnerware, the metal silverware, and everywhere we look we see products made from materials. • Most products are made from many different kinds of materials to satisfy the needs of the product. One way to look at materials is to consider the various generic descriptions such as metals, ceramics, plastics semiconductors, composites

11. Classification of Materials • Metals: • Large number of free electrons, • good conductors of electricity and heat, • not transparent to visible light. • Quite strong, • yet deformable, this accounts for their extensive use in structural applications. 2. Ceramics: • Typically insulative to passage of electricity and heat. • more resistant to high temperatures and harsh environments than metals and polymers. • Ceramics are hard but very brittle.

12. Classification of Materials • Polymers: • Very large molecular structure. • Low densities and may be extremely flexible. • Polymer include your hair to familiar plastic and rubber materials. • Composites: • Consists of more than one material type. Fiberglass is a familiar example in which glass fibers are embedded within a polymeric material. • A composite is designed to display a combination of the best characteristics of each component materials. • Fiber glass acquires strength from the glass and flexibility from the polymer. Many of the recent material developments have involved composite materials.

13. Classification of Materials • Semiconductors: • Electrical characteristics of these materials are extensively sensitive to the presence of minute concentrations of impurity atoms; these concentrations may be controlled over very small regions. • The semiconductors have made possible the advent of integrated circuitry that has totally revolutionized the electronic industry. 6. Organic material (Bio-material): • These are polymeric materials composed of carbon compounds. • All other 5 types of materials stated above may be organic material/ biomaterial. Therefore, this is is not an uniquely defined class.

14. More advanced materials • Smart (or intelligent) materials: These materials are able to sense changes in their environments and respond to these changes in predetermined manners-traits that are found in living organisms. The component of smart material include some type of sensor that detects an input and actuator that performs a responsive and adaptive function. • Nano-Materials: http://en.wikipedia.org/wiki/Nanomaterial Nanotechnology comprises any technological developments on the nanometer scale, usually 0.1-100nm. (One nanometer equals one thousandth of a micrometer or one millionth of a millimeter). Often the properties of materials changes at this length and when we develop new materials having the characteristic properties of nanometer scale then they are called nanomaterials. Nano-transistors are already in use.

15. Which properties of materials are of engineering interest? • Mechanical Properties: (like elasticity, plasticity, toughness, resilience, tensile strength, yield strength, impact strength, ductility, malleability, brittleness, hard ness, Fatigue, Creep etc.) • Thermal Properties: (like Heat capacity, Specific heat, Melting points, thermal expansion, thermal conductivity, thermal shock resistance) • Electrical Properties: (resistivity, conductivity, dielectric strenght, thermoelectricity etc. • Magnetic properties: (Permeablity, coerecive force, hysteresis, superconductivity) • Chemical properties: Chemical composition, corrosion resistance, acidity and alkalinity etc. • Optical properties: refractive index, absorptivity and absorption coefficient, reflectivity etc. • Physical properties: Dimension, appearance, density, color, porosity etc.

16. How to select a material for particular applications Example: “Ductility is defined as capability of a material to undergo deformation under tension without rupture”. • In most of the applications we need high strength and high ductility but any material having high strength has low ductility, so we made a compromise. • Earlier engineers used to made these kind of compromisation by successive approximation method or by trial and error. • Recently we have developed systematic methods to choose reliably among many possible materials capable of a particular application. Some of the popular systematic techniques are • Weighted property indices • Failure analysis

17. Self study • Read • Weighted property indices • Failure analysis techniques yourself. For this purpose use http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392003000400010 And http://media.wiley.com/product_data/excerpt/46/04713592/0471359246.pdf Or read page 4-4 to 4-7 of A Text book of “Material Science and Metallurgy” by O P Khanna.

18. Books used for this lecture • A Text book of Material Science and Metallurgy by O P Khanna. • Material Science and Engineering an Introduction by W.D. Callister Jr. • Elements of Material Science and Enginnering by Lawrence H Van Vlack • A course on electrical engineering materials by S P Seth

19. Self study • Invited Paper: • Dielectric Materials, Devices and Circuits • By S. Jerry Fiedziuszko et al • IEE Transactions on Microwave theory and Techniques, Vol.50,No.3, March 2002