1. Introduction to Engineering Materials
9/13/2018
Introduction to Engineering Materials

2. Why should I study Engineering Materials ?
The world is in the middle of a materials revolution.
Materials science and engineering has transformed every aspect of modern living.
Advances in engineered materials are crucial to the continued vitality of countless industries.
Advances in materials have preceded almost every major technological leap since the beginning of civilization.

3. Why Study Engineering Materials?
To be able to select a material for a given use based on considerations of cost and performance.
To understand the limits of materials and the change of their properties with use.
To be able to create a new material that will have some desirable properties.

4. Overview of the Course
Engineering Materials is an interdisciplinary field involving the properties of matter and its applications to various areas of science and engineering. This science investigates the relationship between the structure of materials at atomic or molecular scales and their macroscopic properties.
The field is concerned with the design, manufacture and use of all classes of materials (including metals, ceramics, semiconductors, polymers and bio materials), and with energy, environmental, health, economic, and manufacturing issues relating to materials.
It emphasizes the study of the structure of materials and Processing- Structure-Property relationship in materials.

5. 9/13/2018
Course Outcomes
Describe the role of engineering materials in the design of systems and their selection strategy.
Apply the knowledge of crystal structure and deformation behavior to select appropriate material.
Discuss how engineering materials respond to applied mechanical loads in both a macroscopic and microscopic sense at ambient temperature and high temperature applications.
Explain the concepts of solid solutions as a basis for constructing phase diagrams.

6. Course Outcomes
Identify a suitable material (Ferrous or Nonferrous) for a given application from standards.
Demonstrate the knowledge of heat treatment process for improving physical and mechanical properties of engineering materials.
Elucidate the need, properties and applications of ceramics and polymers.
Discuss different composite materials (PMC, MMC & CMC), their properties and application with economic and social concerns.

7. Text Books :

8. Chapter Outline An overview of engineering materials ;
Classes of engineering materials, functional and advanced materials;
Materials history and character, Design-limiting properties;
Matching materials to design, Selection strategy- translation, screening, ranking and documentation.

9. Evolution of Material technology

10. The evolution of engineering materials with time

11. From stone age to modern era.
Tutankhamen- sarcophagus, Agamemnon with his bronze sword and mask of gold
Bronze age to 1000 B.C
Iron age B.C to 1620 B.C
Cast iron (1620), Steel (1850), Light alloy (1940)
1960- importance for engg material leading to development in materials ( carbon fiber, metal composites, shape memory alloys).

12. Engineering Materials
Plastics
Metals
Steel
Stainless steel
Die & tool steel
Cast iron
Ferrous
Non-ferrous
Aluminum
Copper
Zinc
Titanium
Tungsten
Thermoplastics
Acrylic
Nylon
ABS
Polyethylene
Polycarbonate
PVC
Thermosets
Phenolic
Polymide
Epoxies
Polyester
Elastomers
Rubber
Polyurethane
Silicone

13. Engineering Materials
Composites
Reinforced plastics
Metal-Matrix
Ceramic-Matrix
Laminates
Ceramics
Glass
Carbides
Nitrides
Graphite
Diamond
Glasses
Glass ceramics
Metals
Plastics

15. Classes of materials Ionic crystals Covalent materials Metal & alloys
Semiconductors
Superconductors
Polymers
Composite materials
Ceramics
Inorganic glasses
Catalysts

16. Ionic Crystals ionic Bond is Formed by transfer of electrons
Example: NaCl,KCl,MgCl2 etc
Synthesis :
NaCl is currently produced by evaporation of seawater or brine from other sources.
Mg(OH)2+ 2 HCl → MgCl2(aq) + 2 H2O
Properties of Ionic Crystals
Solid Crystals have high melting point.
They Conduct electricity in molten state.
Low thermal conductivity.
Soluble in polar solvents.

17. Application Of Ionic Crystals
NaCl is Used for cooking purpose which make food tasty.
preservation of cheese, dairy products, meat, pickles and
sauces.
CaCl2 salt is used as Road salt to remove snow fallen on
road in Cold countries .it lowers the freezing point water.
Potassium chloride produced is used for making fertilizer since the growth of many plants is limited by their potassium intake.
It is used in preparation of salt bridge which connects both the half concenteration cells.
KCL

18. Covalent Materials Covalent bond formed by the Sharing of electrons
Example :Diamond, Graphite, Fullerene etc
DIAMOND
highest hardness and thermal conductivity of any bulk material.
A diamond is a transparent crystal of tetrahedral bonded carbon atoms (sp3)
diamond lattice face centered cubic structure
Cutting and Drilling - diamonds are frequently embedded in
saw blades.
Polishing pads – It is used polish hard surface

19. GRAPHITE
Graphite has a layered, planar structure with hexagonal
lattice of Carbon atoms (SP2 ).
graphite powder with clay mixed in as a binding agent are
used in synthesis of pencil.
FULLURENE
Fullerene is molecule composed entirely of carbon, in the form of a hollow sphere.
Carbon is SP2 hybridization.
Fullerenes consist of 20 hexagonal and 12 pentagonal rings .
Fullerenes are currently applied in cosmetics and sports goods industries .
fullerenes are also used in slow drug delivery in a body

20. Properties of metals and alloys 1.High tensile strength.
Metals & Alloys
Metallic bonding is the bonding between atoms within metals.
Alloy is homogeneous mixture of two or more elements
Example : copper ,Aluminum , Brass, Stainless steel etc.
Properties of metals and alloys
1.High tensile strength.
2.They exhibit magnetic properties.
3.High Electrical conductivity.
Cupro – Nickel alloy

21. Application Of Metals And Alloys
Due to Their electric properties they are used in electric wire and Electrical devices .
Stainless steel alloy is milled into coils, sheets, plates, bars, wire, and tubing to be used in cookware, hardware , surgical instruments.
Brass can be used for the metallic coatings of several lock ,Watch etc.

22. Semiconductors Examples: Si, Ge etc Properties of semiconductors
the bonding is covalent (electrons are shared between atoms). Their electrical properties depend strongly on minute proportions of dopants.
Examples: Si, Ge etc
Dopants:
Boron (3 rd group element )
Phosphorus (5th group element)
Properties of semiconductors
1. They are crystalline and amorphous
2.The conductivity properties lie In-between insulator and conductors.
3. Their conductivity varies with temperature.

23. Application Of Semiconductors
Si wafer in photovoltaic cells to convert light energy
to electric energy.
Semiconductor memory uses semiconductor-based integrated circuits to store information.
A transistor is a semiconductor device used to amplify and switch electronic signals

24. Superconductors
An element , intermetallic alloy or compound that will conduct electricity without resistance below certain Temperature.
Example: YBa2Cu3O7(-178°C),Pb( °C)etc.
PROPERTIES SUPERCONDUCTORS
1.Meissner effect :
Superconductors are diamagnetic compounds which repel
magnetic field.
2.Josephson effect:
When 2 superconductors sheets are separated by small thin insulating material the current can pass through without any voltage.
vjhfngkf

25. Application Of Superconductors
Based on Meissner effect trains can be made to "float" on strong superconducting magnets, virtually eliminating friction between the train and its tracks.
Speed :581 KPh in shanghai.
SQUID's are capable of sensing a change in a magnetic field over a billion times weaker than the force that moves the needle on a compass . With this technology, the body can be probed to certain depths without the need for the strong magnetic fields associated with MRI's.

26. Synthetic Polymers
Polymer: High molecular weight molecule made up of a small repeat
unit (monomer).
A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A
example : polyester ,nylon Bakelite etc.
Types of polymers:
1. Thermoplastics: can be processed by melting (several cycles of
heating and cooling are possible for thermally stabilized polymers)
example: PVC,PET etc
2. Thermosets: cannot be melted or dissolved to be processed: chemical decomposition occurs before softening.
example: Vulcanized rubber Bakelite.

27. Synthesis of Nylon Decanedioyl dichloride in C2H2Cl4
1,6-diaminohexane in aqueous sodium carbonate.
NYLON 6,10
6 indicates the no carbon atoms in amine compound
10 indicates the no of carbon atoms in carbonyl chloride

28. Application Of Synthetic Polymer
Polypropylene the polymer we are using from morning to night

29. Composite Materials Composite Materials offers 1.High Strength
Two inherently different materials that when combined together produce a material with properties that exceed the constituent materials.
Composite materials consist of two main materials.
1.Reinsforcement(Strong load carrying material) EX: aramide, carbon ,fiberglass
2.Matrix (imbedded weaker material) EX: polypropylene ,polyvinyl chloride etc.
Composite Materials offers
1.High Strength
2.Light Weight
3.Design Flexibility
Tensile Properties
Stiffness
Impact Resistance
Transfer Load to Reinforcement
Temperature Resistance
Chemical Resistance

30. Application Of Composite Materials
Carbon fiber composites with polymer matrices, have become the advanced composite materials for aerospace, due to their high strength, high Modulus and low cost.
Helmet and bullet proof jacket Made Up of Aramide Composite material
Fiber-reinforced plastics have reached the stage where they could be used for making wheels.

31. Ceramics 1.Whitewares clays
Ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent cooling.
Example: clay ,Mixed oxides like alumina Zirconia Etc
PROPERTIES OF CERAMICS
Ceramics are Strong solid inert materials.
They withstand chemical erosion due to Acid and Caustic.
These can withstand high temperature of about 1000 °C to1600°C.
TYPES OF CERAMICS
1.Whitewares clays
2.Refaracotories Have high Silicon or Aluminium oxide content.
3.Abrasives. Natural garnet, diamond, Silicon carbide.

32. Application Of Ceramic Materials
WHITE WARES are used in including tableware, wall tiles, pottery products and sanitary ware
REFRACTORIES are used in making fire bricks silica crucible and ovens. Due to there low thermal conductivity and high strength to temperature
Sandpaper is a very common coated abrasive.

33. Glasses Synthesis of glass
Glass is an amorphous (non-crystalline) solid material and
typically brittle and optically transparent.
Silica(SiO2) is a common fundamental constitute of glass.
Synthesis of glass
Mixture of soda ash ,limestone, sand and broken glass in dry condition.
send to furnace and heat to 1600°C
Molding.
Annealing.
shaping.
Marketing .

34. Application of glasses
Borosilicate glasses formerly called Pyrex are often used laboratory reagents due to their resistance to chemical corrosion and heat
fancy glass started to become significant branches of the decorative arts.

35. Catalyst Solid Acid catalyst
Catalyst is substance which alters the rate of reaction without itself undergoing
any chemical change in the reaction
Acid catalyzed reaction usually catalysed by acids
Ex:H2SO4, HCl, AlCl3, HF,BF3 etc.
Operational Difficulties
Corrosive and toxic.
difficult to handle.
effluent disposal.
product separation.
Solid Acid catalyst
Zeolites aluminosilicate
Heteropolyacids H3PW12O40
Sulfated zirconia So4-2 /Zr02
Mixed oxides Al2O3 ,ZnO

36. The menu of engineering materials
The basic families of metals, ceramics, glasses, polymers and elastomers can be combined in various geometries to create hybrids.

38. A hierarchical structure for material classification, ending with a schematic of a record.

39. Hierarchical structure for process classification

40. Most Commonly Used Materials
The following 25 materials are the most commonly used materials in the design of mechanical products; in themselves they represent the broad range of other materials.
Steel and Cast Iron
(plain carbon steel, hot-rolled or cold-drawn)
(plain carbon steel, hot-rolled or cold-drawn)
(heat-treated alloy steel, chromium-molybdenum)
(heat-treated alloy steel, nickel-chromium- molybdenum)
S (stainless steel)
S (stainless steel)
O1 (tool steel)
ASTM (gray cast iron)

41. Most Commonly Used Materials
Aluminum and Copper Alloys
2024 (aluminum, O, T3, T4 or T6)
3003 (aluminum, H12 or H16)
6061 (aluminum, T6)
7075 (aluminum, T6)
C268 (copper)
Other metals
Titanium 6-4
AZ63A (magnesium)

42. Most Commonly Used Materials
Plastics
ABS
Polycarbonate
Nylon 6/6
Polypropylene
Polystyrene
Composite materials
Douglas fir
Fiberglass
Graphite/epoxy
Ceramics
Alumina
Graphite

44. An overview of material properties

45. Properties of Materials
Metallurgical/Mechanical Properties
Physical & chemical
Properties

47. Basic design-limiting material properties

48. Mechanical Properties

49. Thermal Properties

50. Electrical, magnetic and optical Properties

51. Chemical Properties:
Resistance to water, acids, alkalis, organic solvents, oxidation and radiation

52. How the properties of engineering materials affect the way in which products are designed.
INTRINSIC
ATTRIBUTE
Bulk Mechanical Properties
Price and Availability
DESIGN
Bulk Non-mechanical Properties
Production Properties
– Ease of manufacturing, fabrication, joining, finishing
Surface Properties
Aesthetic Properties
– Appearance, Texture, Feel

53. Relative Mechanical Properties of Various Materials at Room Temperature, in Decreasing Order (Metals are in their Alloy Form).

54. Mechanical Properties of Various Materials at Room Temperature

55. Mechanical Properties of Various Materials at Room Temperature

56. Strength to weight ratios of various materials

57. Matching material to design
Strategic thinking:

58. Material Selection Function dictates the choice of material and shape.
Shape restricts the choice of material and process.
Function
Material
Shape
Process
Process is influenced by material
Process interacts with shape.
Material selection and process cannot be separated from the shape and the function of the product, two way interaction.

59. Material and process information for design
Materials selection enters each stage of the design: approximate in the concept stage, more detailed in the embodiment, and most precise in the detailed design stage.
• We narrow the materials search space by screening out unsuitable choices, ranking the remainder, and selecting the most promising.
• Material selection must be linked to process and final form or shape. Process selection runs parallel to material selection. Process choice is influenced by material, shape, and cost.
• The interaction between material, shape, and process is the core of materials selection.

60. The strategy. There are four steps: translation, screening, ranking and documentation.

61. Translation
The first task is that of translation: converting the design requirements into a prescription for selecting a material and a process to shape it.
Any engineering component has one or more functions: to support a load, to contain a pressure, to transmit heat, and so forth. This must be achieved subject to constraints: that certain dimensions are fixed, that the component must carry the design loads without failure, that it insulates or conducts, that it can function in a certain range of temperature and in a given environment, and many more.

62. Translation
In designing the component, the designer has one or more objectives: to make it as cheap as possible, perhaps, or as light, or as safe, or perhaps some combination of these.
Certain parameters can be adjusted in order to optimize the objective – the designer is free to vary dimensions that are not constrained by design requirements and, most importantly, free to choose the material for the component. We refer to these as free variables.

63. Function, constraints, objectives and free variables
Common constraints and objectives

65. Screening
Screening, eliminates candidates that cannot do the job at all because one or more of their attributes lies outside the limits set by the constraints.
As examples, the requirement that “the component must function in boiling water”, or that “the component must be transparent” imposes obvious limits on the attributes of maximum service temperature and optical transparency that successful candidates must meet.
We refer to these as attribute limits.

66. Ranking
To rank the materials that survive the screening step we need optimization criteria. They are found in material indices.
A material index measures how well a candidate that has passed the screening steps can perform, that is, meet the objective. Performance is sometimes limited by a single property, sometimes by a combination of them.
Thus the best materials for buoyancy are those with the lowest density, ρ; those best for thermal insulation the ones with the smallest values of the thermal conductivity, λ, provided, of course, that they also meet all other constraints imposed by the design.
Here maximizing or minimizing a single property maximizes performance. Often it is not one, but a group of properties that are relevant.

67. Documentation
The outcome of the steps so far is a ranked short-list of candidates that meet the constraints and that maximize or minimize the criterion of excellence, whichever is required.
You could just choose the top-ranked candidate, but what hidden weaknesses might it have? What is its reputation? Has it a good track record? To proceed further we seek a detailed profile of each: its documentation.

68. Documentation
Typically, it is descriptive, graphical or pictorial: case studies of previous uses of the material, details of its corrosion behavior in particular environments, of its availability and pricing, warnings of its environmental impact. Such information is found in handbooks, suppliers’ data sheets, CD-based data sources and high quality Web sites.
Documentation helps narrow the short-list to a final choice, allowing a definitive match to be made between design requirements and material attributes.

69. Part of a record for a material, ABS
Part of a record for a material, ABS. It contains numeric data, text and image-based information

70. Part of a record for a process, injection molding
Part of a record for a process, injection molding. The image shows how it works, and the numeric and Boolean data and text document its attributes.

71. Summary and conclusions
The number of engineering materials is large: tens of thousands, at a conservative estimate. The designer must select, from this vast menu, the few best suited to his task. This, without guidance, can be a difficult and haphazard business, so there is a temptation to choose the material that is ‘‘traditional’’ for the application: glass for bottles; steel cans. That choice may be safely conservative, but it rejects the opportunity for innovation.
Engineering materials are evolving faster, and the choice is wider than ever before. Examples of products in which a new material has captured a market are as common as well as plastic bottles. Or aluminum cans. Or polycarbonate eyeglass lenses. Or carbon-fiber golf club shafts.
It is important in the early stage of design, or of re-design, to examine the full materials menu, not rejecting options merely because they are unfamiliar.

72. Review of basics by IGS

73. Supplementary slides

74. Application of Most Commonly Used Materials
Component
Material

75. Application of Most Commonly Used Materials
Component
Material

76. Application of Most Commonly Used Materials
Component
Material