Introduction To Materials Science and Engineering, Ch. 1University of Tennessee, Dept. of Materials Science and Engineering1Chapter 1 Materials for EngineeringA fly-by during deployment of the aircraft carrier USS Stennis. The pilot was grounded for 30 days, but he likes the picture and thinks it was worth it.Introduction To Materials Science and Engineering, Ch. 1University of Tennessee, Dept. of Materials Science and Engineering2Materials Science and Engineering• Materials Science – Investigating relationships that exist between the structure and properties of materials• Materials Engineering– Is, on the basis of these structure-property correlations, designing or engineering the structure of a material to produce a pre-determined set of propertiesIntroduction To Materials Science and Engineering, Ch. 1University of Tennessee, Dept. of Materials Science and Engineering3Structure• Sub atomic – electrons and nuclei (protons and neutrons)• Atomic – organization of atoms or molecules• Microscopic – groups of atoms that are normally agglomerated together• Macroscopic – viewable with the un-aided eyeIntroduction To Materials Science and Engineering, Ch. 1University of Tennessee, Dept. of Materials Science and Engineering4Terminologymil = 1 / 1000 inch = 25.4 µmmicrometer = 1 / 1,000,000 meter = 1µmAngstrom = 1 / 10,000,000,000 meter = 1Å1 MICROMETER IS TWO WAVELENGTHS OF GREEN LIGHT LONGA HAIR IS 100 MICROMETERSA 1 MICRON WIDE LINE ON A CDIS THE SAME SCALE AS A 100 FOOTWIDE ROAD ON NORTH AMERICAIntroduction To Materials Science and Engineering, Ch. 1University of Tennessee, Dept. of Materials Science and Engineering5Progress in atomic-level understandingDNA~2 nm wideThings Natural Things ManmadeTHE SCALE OF THINGS10 nmCell membraneATP synthaseSchematic, central coreCat~ 0.3 mDust mite300 µmMonarch butterfly~ 0.1 mMEMS (MicroElectroMechanical Systems) Devices10 -100 µm wideRed blood cellsPollen grainFly ash~ 10-20 µm Bee~ 15 mmAtoms of siliconspacing ~tenths of nmHead of a pin1-2 mmMagnetic domains garnet film11 µm wide stripesProgress in miniaturizationIndium arsenidequantum dot Quantum dot array --germanium dots on siliconMicroelectronicsObjects fashioned frommetals, ceramics, glasses, polymers ...Human hair~ 50 µm wideThe Microworld0.1 nm1 nanometer (nm)0.01 µm10 nm0.1 µm100 nm1 micrometer (µm)0.01 mm10 µm0.1 mm100 µm1 millimeter (mm)0.01 m1 cm10 mm0.1 m100 mm1 meter (m)100m10-1m10-2m10-3m10-4m10-5m10-6m10-7m10-8m10-9m10-10mVisiblespectrumThe NanoworldThe 21st century challenge -- Fashion materials at the nanoscale with desired properties and functionalityRed blood cellswith white cell~ 2-5 µmIntroduction To Materials Science and Engineering, Ch. 1University of Tennessee, Dept. of Materials Science and Engineering6ProcessingStructurePropertiesPerformanceIntroduction To Materials Science and Engineering, Ch. 1University of Tennessee, Dept. of Materials Science and Engineering7ex: hardness vs structure of steel• Properties depend on structureData obtained from Figs. 10.21(a)and 10.23 with 4wt%C composition,and from Fig. 11.13 and associateddiscussion, Callister 6e.Micrographs adapted from (a) Fig.10.10; (b) Fig. 9.27;(c) Fig. 10.24;and (d) Fig. 10.12, Callister 6e.ex: structure vs cooling rate of steel• Processing can change structureStructure, Processing, & PropertiesCooling Rate (C/s)1002003004005006000.01 0.1 1 10 100 1000(a)30µm(b)30µm(d)30µm(c)4µmHardness (BHN)Introduction To Materials Science and Engineering, Ch. 1University of Tennessee, Dept. of Materials Science and Engineering81.Pick Application Determine required Properties2.Properties Identify candidate Material(s)3.Material Identify required ProcessingProcessing: changes structureand overall shapeex: casting, sintering, vapor deposition, dopingforming, joining, annealing.Properties: mechanical, electrical, thermal,magnetic, optical, deteriorative.Material: structure, composition.The Materials Selection ProcessIntroduction To Materials Science and Engineering, Ch. 1University of Tennessee, Dept. of Materials Science and Engineering9Composition, Bonding, Crystal Structure and Microstructure DEFINE Materials PropertiesCompositionBonding Crystal StructureThermomechanicalProcessingMicrostructureMechanicalPropertiesElectrical & MagneticPropertiesOptical PropertiesThermal PropertiesIntroduction To Materials Science and Engineering, Ch. 1University of Tennessee, Dept. of Materials Science and Engineering10T (°C)-200 -100 0Cu + 3.32 at%NiCu + 2.16 at%Nideformed Cu + 1.12 at%Ni123456Resistivity, ρ (10-8 Ohm-m)0Cu + 1.12 at%Ni“Pure” Cu• Electrical Resistivity of Copper:• Adding “impurity” atoms to Cu increases resistivity.• Deforming Cu increases resistivity.Adapted from Fig. 18.8, Callister 6e.(Fig. 18.8 adapted from: J.O. Linde,Ann Physik5, 219 (1932); andC.A. Wert and R.M. Thomson,Physics of Solids, 2nd edition,McGraw-Hill Company, New York,1970.)ELECTRICALIntroduction To Materials Science and Engineering, Ch. 1University of Tennessee, Dept. of Materials Science and Engineering11• Magnetic Permeabilityvs. Composition:--Adding 3 atomic % Simakes Fe a betterrecording medium!Magnetic FieldMagnetizationFe+3%SiFeAdapted from C.R. Barrett, W.D. Nix, andA.S. Tetelman, The Principles ofEngineering Materials, Fig. 1-7(a), p. 9,1973. Electronically reproducedby permission of Pearson Education, Inc.,Upper Saddle River, New Jersey.Fig. 20.18, Callister 6e.(Fig. 20.18 is from J.U. Lemke, MRS Bulletin,Vol. XV, No. 3, p. 31, 1990.)• Magnetic Storage:--Recording mediumis magnetized byrecording head.MAGNETICIntroduction To Materials Science and Engineering, Ch. 1University of Tennessee, Dept. of Materials Science and Engineering12• Transmittance:--Aluminum oxide may be transparent, translucent, oropaque depending on the material structure. Adapted from Fig. 1.2,Callister 6e.(Specimen preparation,P.A. Lessing; photo by J. Telford.)single crystalpolycrystal:low porositypolycrystal:high porosityOPTICALIntroduction To Materials Science and Engineering, Ch. 1University of Tennessee, Dept. of Materials Science and Engineering13• Stress & Saltwater...--causes cracks! • Heat treatment: slowscrack speed in salt water! 4µm--material:7150-T651 Al "alloy"(Zn,Cu,Mg,Zr)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