1. Introductry Lecture on Material Science

2. Historical Perspective Stone/wood -> Bronze -> Iron -> Advanced materials (ceramic, semiconductors, polymers, composites…).

6. Classes have overlap, so some materials fit into more than one class.

7. Metals

8. Iron and Steel

9. Alloys and Superalloys (e.g. aerospace applications)

10. Intermetallic Compounds (high-T structural materials)

11. Ceramics

12. Structural Ceramics (high-temperature load bearing)

13. Refractories (corrosion-resistant, insulating)

14. Whitewares (e.g. porcelains)

15. Glass

16. Electrical Ceramics (capacitors, insulators, transducers, etc.)

17. Chemically Bonded Ceramics (e.g. cement and concrete) 5

19. Plastics

20. Liquid crystals

21. Adhesives

22. Electronic Materials

23. Silicon and Germanium

24. III-V Compounds (e.g. GaAs)

25. Photonic materials (solid-state lasers, LEDs)

26. Composites

27. Particulate composites (small particles embedded in a different material)

28. Laminate composites (golf club shafts, tennis rackets, Damaskus swords)

29. Fiber reinforced composites (e.g. fiberglass)

30. Biomaterials (really using previous 5, but bio-mimetic)

31. Man-made proteins (cytoskeletal protein rods or “artificial bacterium”)

32. Biosensors (Au-nanoparticles stabilized by encoded DNA for anthrax detection)

33. Drug-delivery colloids (polymer based) 6

34. Periodic Table of Elements From http://64.224.111.143/handbook/periodic/ 7

36. Relatively good strength(defined later)

37. Dense

38. Malleable or ductile: high plasticity (defined later)

39. Resistant to fracture: tough

40. Excellent conductors of electricity and heat

41. Opaque to visible light

42. Shiny appearance

43. Thus, metals can be formed and machined easily, and are usually long-lasting materials.

44. They do not react easily with other elements, however, metals such as Fe and Al do form compounds readily (such as ores) so they must be processed to extract base metals.

45. One of the main drawbacks is that metals do react with chemicals in the environment, such as iron-oxide (rust).

46. Many metals do not have high melting points, making them useless for many applications. 8

49. Structures: buildings, bridges, etc.

50. Automobiles: body, chassis, springs, engine block, etc.

51. Airplanes: engine components, fuselage, landing gear assembly, etc.

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

53. Machine tools: drill bits, hammers, screwdrivers, saw blades, etc.

54. Shape memory materials: eye glasses

55. Magnets

57. Alloys (Cu-Sn=bronze, Cu-Zn=brass, Fe-C=steel, Pb-Sn=solder, NiTinol)

58. Intermetallic compounds (e.g. Ni3Al) What’s the largest use of shape-memory nitinol? 10

60. Composed of a mixture of metal and nonmetal atoms

61. Lower density than most metals

62. Stronger than metals

63. Low resistance to fracture: low toughness or brittle

64. Low ductility or malleability: low plasticity

65. High melting point

66. Poor conductors of electricity and heat

67. Single crystals are transparent

68. Where metals react readily with chemicals in the environment and have low application temperatures in many cases, ceramics do not suffer from these drawbacks.

69. Ceramics have high-resistance to environment as they are essentially metals that have already reacted with the environment, e.g. Alumina (Al2O3) and Silica (SiO2, Quartz).

70. Ceramics are heat resistant. Ceramics form both in crystalline and non-crystalline phases because they can be cooled rapildy from the molten state to form glassy materials. 11

71. Classes and Properties: Ceramics Elemental occurring in ceramics are in blue 12

73. Abrasives

74. Thermal insulation and coatings

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

76. Corrosion resistant applications

77. Electrical devices: capacitors, varistors, transducers, etc.

78. Highways and roads (concrete)

79. Biocompatible coatings (fusion to bone)

80. Self-lubricating bearings

81. Magnetic materials (audio/video tapes, hard disks, etc.)

82. Optical wave guides

84. Mixed-metal oxides (SrTiO3, MgAl2O4, YBa2Cu3O7-x, having vacancy defects.)

85. Nitrides (Si3N4, AlN, GaN, BN, and TiN, which are used for hard coatings.)13

87. Low melting temperature.

88. Some are crystals, many are not.

89. Most are poor conductors of electricity and heat.

90. Many have high plasticity.

91. A few have good elasticity.

92. Some are transparent, some are opaque

93. Polymers are attractive because they are usually lightweight and inexpensive to make, and usually very easy to process, either in molds, as sheets, or as coatings.

94. Most are very resistant to the environment.

95. They are poor conductors of heat and electricity, and tend to be easy to bend, which makes them very useful as insulation for electrical wires. They are also14

97. Thermoplastics are long-chain polymers that slide easily past one another when heated, hence, they tend to be easy to form, bend, and break. 15

98. Classes and Properties: Polymers Elements that compose polymers: limited 16

100. Containers

101. Moldable products (computer casings, telephone handsets, disposable razors)

102. Clothing and upholstery material (vinyls, polyesters, nylon)

103. Water-resistant coatings (latex)

104. Biodegradable products (corn-starch packing “peanuts”)

105. Biomaterials (organic/inorganic intefaces)

106. Liquid crystals

107. Low-friction materials (teflon)

108. Synthetic oils and greases

109. Gaskets and O-rings (rubber)

110. Soaps and surfactants17

112. Regular arrangement of atoms (crystals, but not, e.g., solar cell amorphous Si)

113. Extremely controlled chemical purity

114. Adjustable conductivity of electricity

115. Opaque to visible light

116. Shiny appearance

117. Some have good plasticity, but others are fairly brittle

118. Some have an electrical response to light

119. Semiconductors define the Digitial Revolution and Information Age.

120. Starting with extremely pure crystalline form, their electrical conductions can be controlled by impurity doping (and defect).

121. The result is a tiny electrical switching called a "transistor". Transistors (at present) can be packed to about 1 billion in the size of a Lincoln Penny.18

122. Classes and Properties: Semiconductors Elements occurring in semiconductors 19

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

125. Solid-state lasers

126. Light-emitting diodes (LEDs)

127. Flat panel displays

128. Solar cells

129. Radiation detectors

130. Microelectromechanical devices (MEMS)

131. Examples: Si, Ge, GaAs, and InSb20

133. Properties depend on amount and distribution of each type of material.

135. Aerospace materials

136. Thermal insulation

137. Concrete

138. "Smart" materials (sensing and responding)

140. Space shuttle heat shields (interwoven ceramic fibers)

141. Paints (ceramic particles in latex)

142. Tank armor (ceramic particles in metal)21

143. Materials Science From the polymers in the chair you’re sitting on, the metal ball-point pen you’re using, and the concrete that made the building you live or work in to the materials that make up streets and highways and the car you drive, plane you using. All these items are products of materials science and technology. Briefly defined, materials science is the study of “stuff.” Materials science is the study of solid matter.

144. BREAK

145. Material Science The discipline of investigating the relationships that exist between the structures and properties of materials and its performance.

146. What is Materials Science and Engineering ? Processing -> Structure -> Properties -> Performance

148. Calcinating

149. Sintering

150. Casting

151. Forging

152. Stamping

154. Thermal

155. Electrical

156. Magnetic

157. Optical

158. Corrosive

159. Deteriorative characteristics

160. Microscopy: Optical, transmission electron, scanning tunneling

161. X-ray, neutron, e- diffraction

162. Spectroscopy26

163. Materials Science and Engineering Core, including the end-user Source: Materials science and engineering—forging stronger links to users, NRC 1999

165. That is why we call it materials ENGINEERING

168. low UTS

169. low YS

170. high ductility

171. round grains

172. At h2, L2

173. high UTS

174. high YS

175. low ductility

176. elongated grainsStructure determines Properties but Processing determines Structure!

177. Multiple Length Scales Critical in Engineering In Askeland and Phule’s book, from J. Allison and W. Donlon (Ford Motor Company) 31

179. One goal of materials engineering is to select materials with suitable properties for a given application, so it’s a sensible approach.

180. Just as for classes of materials, there is some overlap among the properties, so the divisions are not always clearly defined Mechanical properties A. Elasticity and stiffness (recoverable stress vs. strain) B. Plasticity (non-recoverable stress vs. strain) C. Strength D. Brittleness or Toughness E. Fatigue 32

181. Properties of Materials Electrical properties A. Electrical conductivity and resistivity Dielectric properties A. Polarizability B. Capacitance C. Ferroelectric properties D. Piezoelectric properties E. Pyroelectric properties Magnetic properties A. Paramagnetic properties B. Diamagnetic properties C. Ferromagnetic properties 33

182. Properties of Materials Optical properties A. Refractive index B. Absorption, reflection, and transmission C. Birefringence (double refraction) Corrosion properties Deteriorative properties Biological properties A. Toxicity B. bio-compatibility 34

183. 400 300 (W/m-K) 200 Thermal Conductivity 100 0 0 10 20 30 40 Composition (wt% Zinc) 100mm THERMAL Properties • Space Shuttle Tiles: --Silica fiber insulation offers low heat conduction. • Thermal Conductivity of Copper: --It decreases when you add zinc! Adapted from Fig. 19.4W, Callister 6e. (Courtesy of Lockheed Aerospace Ceramics Systems, Sunnyvale, CA) (Note: "W" denotes fig. is on CD-ROM.) Adapted from Fig. 19.4, Callister 7e. (Fig. 19.4 is adapted from Metals Handbook: Properties and Selection: Nonferrous alloys and Pure Metals, Vol. 2, 9th ed., H. Baker, (Managing Editor), American Society for Metals, 1979, p. 315.)

184. Fe+3%Si Fe Magnetization Magnetic Field MAGNETIC Properties • Magnetic Permeability vs. Composition: --Adding 3 atomic % Si makes Fe a better recording medium! • Magnetic Storage: --Recording medium is magnetized by recording head. Adapted from C.R. Barrett, W.D. Nix, and A.S. Tetelman, The Principles of Engineering Materials, Fig. 1-7(a), p. 9, Electronically reproduced by permission of Pearson Education, Inc., Upper Saddle River, New Jersey. Fig. 20.23, Callister 7e. (Fig. 20.23 is from J.U. Lemke, MRS Bulletin, Vol. XV, No. 3, p. 31, 1990.)

185. -8 “as-is” 10 “held at 160ºC for 1 hr before testing” crack speed (m/s) -10 10 Alloy 7178 tested in saturated aqueous NaCl solution at 23ºC increasing load 4mm --material: 7150-T651 Al "alloy" (Zn,Cu,Mg,Zr) Adapted from Fig. 11.26, Callister 7e. (Fig. 11.26 provided courtesy of G.H. Narayanan and A.G. Miller, Boeing Commercial Airplane Company.) DETERIORATIVE Properties • Heat treatment: slows crack speed in salt water! • Stress & Saltwater... --causes cracks! Adapted from Fig. 11.20(b), R.W. Hertzberg, "Deformation and Fracture Mechanics of Engineering Materials" (4th ed.), p. 505, John Wiley and Sons, 1996. (Original source: Markus O. Speidel, Brown Boveri Co.) Adapted from chapter-opening photograph, Chapter 17, Callister 7e. (from Marine Corrosion, Causes, and Prevention, John Wiley and Sons, Inc., 1975.)

187. by mechanical deformationFig. 19.8 Callister Resistivity 10-8 Ohms-m scattering of e- by microstructure scattering of e- impurities scattering of e- by phonons T (0C) 38

189. These rigid-walled, nano-scale capsules have potential drug delivery applications.G. Wong, MatSE (UIUC) Nanometers: things that span ~10–9 m 100 nm ~ 500 atom diameters 39

191. changes due to alloying in metals (even though same structure)Silica (SiO2) fibres in space shuttle tiles Fig. 23.18 Callister 40

192. bcc Fe Fig. 6.14 Callister - 200 C - 100 C Stress (MPa) + 25 C Strain Deterioration and Failure e.g., Stress, corrosive environments, embrittlement, incorrect structures from improper alloying or heat treatments, … USS Esso Manhattan 3/29/43 Fractured at entrance to NY harbor http://www.uh.edu/liberty/photos/liberty_summary.html 41

193. Questions ??

194. The COMET: first jet passenger plane - 1954 In 1949, the COMET aircraft was a newly designed, modern jet aircraft for passenger travel. It had bright cabins due to large, square windows at most seats. It was composed of light-weight aluminum. In early 1950's, the planes began falling out of the sky. These tragedies changed the way aircraft were designed and the materials that were used. The square windows were a "stress concentrator" and the aluminum alloys used were not "strong"enough to withstand the stresses. Until then, material selection for mechanical design was not really considered in designs. 43

195. Concorde Jetliner - August, 2000 A Concorde aircraft, one of the most reliable aircraft of our time, was taking off from Paris Airport when it burst into flames and crashed killing all on board. Amazingly, the pilot knowingly steered the plane toward a less populated point to avoid increased loss of life. Only three people on the ground were killed. Investigations determined that a jet that took-off ahead of Concorde had a fatigue-induced loss of a metallic component of the aircraft, which was left on runway. During take-off, the Concorde struck the component and catapulted it into the wing containing filled fuel tanks. From video, the tragedy was caused from the spewing fuel catching fire from nearby engine exhaust flames and damaging flight control. 44

196. World Trade Center Collapse CNN Tubularconstructed building. Well designed and strong. Strong but not from buckling. Supports lost at crash site, and the floor supported inner and outer tubular structures. Heat from burning fuel adds to loss of structural support from softening of steel (strength vs. T, stress-strain behavior). Building “pancakes” due to enormous buckling loads. See estimate by Tom Mackie in MIE 45

198. It can also be a problem, e.g. Ga is a fast diffuser at Al grain boundaries and make Al catastrophically brittle(noplastic behaviorvs.strain).

199. Need to know T vs. c phase diagrams for what alloying does.

200. Need to know T-T-T (temp - time - transition) diagrams to know treatment.T vs c for Ga-In Bringing an plane out of the sky! When Ga (in liquid state) is alloyed to Al it diffusesrapidly alonggrain boundaries(more volume) making bonds weaker and limiting plastic response. liquid Liquid at R.T. All these are concepts we will tackle. T.J. Anderson and I. Ansara, J. Phase Equilibria, 12(1), 64-72 (1991). 46

201. The Materials Selection Process 1. Pick Application Determine required Properties Properties: mechanical, electrical, thermal, magnetic, optical, deteriorative. 2. Properties Identify candidate Material(s) Material: structure, composition. 3. Material Identify required Processing Processing: changes structure and overall shape ex: casting, sintering, vapor deposition, doping forming, joining, annealing.

204. Without the right material, a good engineering design is wasted. Need the right material for the right job! “Because without materials, there is no engineering.”

205. Thanks