Aerospace Materials – AERO 220 PDF

Aerospace Materials – AERO 220 Dr. Rehan Umer COURSE MATERIALS (with text) Text Book: Materials Science and Engineering W.D. Callister, Jr. and D.G. Rethwisch, 10th edition, John Wiley and Sons, Inc. (2018)....

Aerospace Materials – AERO 220 Dr. Rehan Umer COURSE MATERIALS (with text) Text Book: Materials Science and Engineering W.D. Callister, Jr. and D.G. Rethwisch, 10th edition, John Wiley and Sons, Inc. (2018). 2 GRADING Assignment 10% In-lecture quizzes 20% Based on core homework problems Midterm 30% Final 40% 3 Class rules 1. Class starts on time. 2. Mobile phones must be turned off while in class. 3. Conversations are not allowed. 4. Eating in class is not allowed. 5. Disruptive behavior of any kind is not allowed. P4 AERO 220: Materials Engineering Course Objective Introduce fundamental concepts in Materials Science You will learn about material structure how structures dictate final properties how processing can change a structure This course will help you to use materials properly realize new design opportunities with materials 5 History of mankind ~ history of materials! P6 Some history… “ The Assyrian army was feared for many reasons one including the use of iron in their weapons. The Assyrians were the first to use iron in spears, swords, shields and armor. They even tipped their battering rams for extra effectiveness. When the Assyrians first attacked their enemies with these awesome novelties of war, it caused almost as profound a reaction as the atom bomb has in our time. “ http://www.associatedcontent.com/article/98591/assyrian_weapons_and_warfare_paper.html P7 Classification/Nomenclature Matter Mixture Air, bronze, jus, fiberglass… Pure substance Compound H2O, CO2, CH4, … Element H, H2, O2, … P8 Classification Metals: steel, aluminum, gold, … Ceramics: glass, porcelain, … Polymers: plastics, rubber, … Composites: bone, wood, fiber glass, … P9 P10  GLARE http://www.airporttech.tc.faa.gov/Safety/pic/patterson8.jpg P11 http://www.flightglobal.com/assets/getAsset.aspx?ItemID=9119 P12 Wind Turbine P13 Boat Building http://avobee.com/sh/technology.htm P14 Materials for engineering applications Design Performance Construction Choice of Material P15 Materials for engineering applications Choices are based on properties! Mechanical Electrical Thermal Magnetic Optical Deteriorative/long-term behavior P16 Structure …. depends on processing Subatomic Hydrogen, http://en.wikipedia.org/wiki/Hydrogen Atomic Diamond Nano-structured , Textbook, ch.12 materials! Graphite, Textbook, ch.12 Methane, http://en.wikipedia.org/wiki/Methane “Microscopic” NiTi smart material, http://www.univie.ac.at/IK-nanostructured-materials/Gallery.html Macroscopic P17 P18  Flax (Linen) Silicon Carbide P19  Tea bag Washing Powder Human Hair Aluminum P20 Structure, Processing, & Properties Properties depend on structure ex: hardness vs structure of steel (d) 6 00 30 mm Hardness (BHN) 5 00 (c) Data obtained from Figs. 10.30(a) and 10.32 with 4 wt% C composition, 4 00 (b) and from Fig. 11.14 and associated (a) discussion, Callister & Rethwisch 8e. Micrographs adapted from (a) Fig. 4 mm 10.19; (b) Fig. 9.30;(c) Fig. 10.33; 3 00 and (d) Fig. 10.21, Callister & Rethwisch 8e. 30 mm 2 00 30 mm 100 0.01 0.1 1 10 100 1000 Cooling Rate (ºC/s) ex: structure vs cooling rate of steel Processing can change structure 21 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, vapor deposition, forming, joining, annealing etc.. 22 Example – Hip Implant With age or certain illnesses joints deteriorate. Particularly those with large loads (such as hip). Adapted from Fig. 22.25, Callister 7e. 23 Example – Hip Implant Requirements/issues mechanical strength (many cycles) good lubricity biocompatibility Adapted from Fig. 22.26, Callister 7e. 24  Hip Implant Key problems to overcome Ball fixation agent to hold acetabular cup cup lubrication material femoral stem – fixing agent (“glue”) must avoid any debris in cup Acetabular Cup and Liner Femoral Stem Adapted from chapter-opening photograph, Chapter 22, Callister 7e. 25 Structure P26 PROPERTIES Electrical Electrical Resistivity of Copper: 6 Adapted from Fig. 18.8, Callister & Rethwisch 8e. (Fig. 18.8 adapted from: J.O. Linde, Ann Physik 5, 219 (1932); and C.A. Wert and R.M. Thomson, Physics of 5 Solids, 2nd edition, McGraw-Hill Company, New York, 1970.) 4 Resistivity, r (10 Ohm-m) 3 -8 2 1 0 -200 -100 0 T (ºC) Adding “impurity” atoms to Cu increases resistivity. Deforming Cu increases resistivity. 27  THERMAL Space Shuttle Tiles: Thermal Conductivity -- Silica fiber insulation of Copper: offers low heat conduction. -- It decreases when you add zinc! Adapted from chapter-opening photograph, Chapter 17, Callister & Rethwisch 3e. (Courtesy of Lockheed Missiles and Space 400 Company, Inc.) 300 Thermal Conductivity (W/m-K) 200 100 0 0 10 20 30 40 Composition (wt% Zinc) Adapted from Adapted from Fig. 19.4, Callister & Rethwisch 8e. (Fig. 19.4 is adapted Fig. 19.4W, Callister 6e. (Courtesy from Metals Handbook: Properties and Selection: Nonferrous alloys and of Lockheed Aerospace Ceramics Pure Metals, Vol. 2, 9th ed., H. Baker, (Managing Editor), American Systems, Sunnyvale, CA) Society for Metals, 1979, p. 315.) (Note: "W" denotes fig. is on CD- ROM.) 28 100 mm MAGNETIC Magnetic Storage: Magnetic Permeability -- Recording medium vs. Composition: is magnetized by -- Adding 3 atomic % Si recording head. makes Fe a better recording medium! Fe+3%Si Magnetization Fe Magnetic Field Fig. 20.23, Callister & Rethwisch 8e. 29  OPTICAL Transmittance: -- Aluminum oxide may be transparent, translucent, or opaque depending on the material structure. polycrystal: polycrystal: low porosity high porosity single crystal Adapted from Fig. 1.2, Callister & Rethwisch 8e. (Specimen preparation, P.A. Lessing; photo by S. Tanner.) 30 DETERIORATIVE Stress & Saltwater... Heat treatment: slows -- causes cracks! crack speed in salt water! -8 10 “as-is” “held at crack speed (m/s) 160ºC for 1 hr before testing” -10 Alloy 7178 tested in 10 saturated aqueous NaCl solution at 23ºC increasing load 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 16, Callister & Rethwisch 3e. (from Marine Corrosion, Causes, and Prevention, John Wiley and Sons, Inc., 1975.) 4 mm -- material: A steel bar bent into horse-shoe 7150-T651 Al "alloy" (Zn,Cu,Mg,Zr) Adapted from Fig. 11.26, Callister & Rethwisch 8e. (Provided courtesy of G.H. Narayanan and A.G. Miller, Boeing Commercial Airplane Company.) 31 Classification Metals: steel, aluminum, gold, … Ceramics: glass, porcelain, … Polymers: plastics, rubber, … Composites: bone, wood, fiber glass, … P32  Metals Composed of one or more metallic and/or non metallic elements Dense packing of atoms Stiff, strong and ductile Conductors of heat and electricity Magnetic properties P33  Ceramics Compounds of metallic and non metallic elements Oxides, nitrides, and carbides Stiff and strong like metals but very brittle Insulators of heat and electricity P34  Polymers Organic compounds of carbon, hydrogen and other non metallic elements Long carbon chains Thermoplastics or thermosets Polypropylene, Polyethylene, PVC, rubber.. Very low densities Not very stiff and strong as compared to metals and ceramics. Easily formed into shape Low conductivity P35  Composites Composed of two (or more) individual materials To achieve a combination of properties that is not displayed by any single material Common and familiar composites is fiberglass, CFRP P36 Composites http://www.bmw-i-usa.com/en_us http://www.bock.co.za/aviation.php Carbon fiber blades P37 Composite Sandwich Structure http://www.instructables.com/id/Coffee-Cup-Honeycomb-Sandwich-Structure/# P38  ADVANCE MATERIALS Semiconductors  Properties of metals and ceramics… Biomaterials  Naturally occurring materials such as wood… Smart Materials  Shape memory alloys, Piezoelectric ceramics etc… Nano Materials  Materials having dimensions at nano scale… P39 Comparison of properties: stiffness Carbon nanotube P40 Comparison of properties: conductivity P41 SUMMARY Course Goals: Use the right material for the job. Understand the relation between properties, structure, and processing. Recognize new design opportunities offered by materials selection. 42