ME 2105 Introduction to Material Science (for Engineers) Dr. Richard R. Lindeke, Ph.D. B Met. Eng. University of Minnesota, 1970 Master’s Studies, Met Eng. Colorado School of Mines, 1978-79 (Electro-Slag Welding of Heavy Section 2¼ Cr 1 Mo Steels) Ph.D., Ind. Eng. Penn State University, 1987 (Foundry Engineering – CG Alloy Development)
Syllabus and Website: • Review the Syllabus • Attendance is your job – come to class! • Final is Common Time Thursday, Friday or Sat (Dec 17, 18 or 19) • Semi-Pop Quizzes and homework/Chapter Reviews (Ch 14) – (20% of your grade!) – note, homework is suggested to prepare for quizzes and exams! • Don’t copy from others; don’t plagiarize – its just the right thing to do!! • Course Website: http://www.d.umn.edu/~rlindek1/ME2105/Cover_Page.htm
Materials Science and Engineering • It all about the raw materials and how they are processed • That is why we call it materials ENGINEERING • Minor differencesin Raw materials or processing parameters can meanmajor changes in the performanceof the final material or product
Materials Science and Engineering • Materials Science • The discipline of investigating the relationships that exist between the structures and properties of materials. • Materials Engineering • The discipline of designing or engineering the structure of a material to produce a predetermined set of properties based on established structure-property correlation. • Four Major Components of Material Science and Engineering: • Structure of Materials • Properties of Materials • Processing of Materials • Performance of Materials
And Remember: Materials “Drive” our Society! • Ages of “Man” we survive based on the materials we control • Stone Age – naturally occurring materials • Special rocks, skins, wood • Bronze Age • Casting and forging • Iron Age • High Temperature furnaces • Steel Age • High Strength Alloys • Non-Ferrous and Polymer Age • Aluminum, Titanium and Nickel (superalloys) – aerospace • Silicon – Information • Plastics and Composites – food preservation, housing, aerospace and higher speeds • Exotic Materials Age? • Nano-Material and bio-Materials – they are coming and then …
And Formula One – the future of automotive is … http://www.autofieldguide.com/articles/050701.html
CG Structure – but with great care! Poor “Too Little” Good Structure 45KSI YS; 55KSI UTS Poor “Too Much”
Our Text: Introduction to Materials Science for Engineers By James F. Shackelford Seventh Edition, Pearson/Prentice Hall, 2009.
Doing Materials! • Engineered Materials are a function of: • Raw Materials Elemental Control • Processing History • Our Role in Engineering Materials then is to understand the application and specify the appropriate material to do the job as a function of: • Strength: yield and ultimate • Ductility, flexibility • Weight/density • Working Environment • Cost: Lifecycle expenses, Environmental impact* * Economic and Environmental Factors often are the most important when making the final decision!
Introduction • List the Major Types of MATERIALS That You Know: • METALS • CERAMICS/Glasses • POLYMERS • COMPOSITES • ADVANCED MATERIALS( Nano-materials, electronic materials)
Metals Steel, Cast Iron, Aluminum, Copper, Titanium, many others Ceramics Glass, Concrete, Brick, Alumina, Zirconia, SiN, SiC Polymers Plastics, Wood, Cotton (rayon, nylon), “glue” Composites Glass Fiber-reinforced polymers, Carbon Fiber-reinforced polymers, Metal Matrix Composites, etc. Introduction, cont.
Periodic table ceramic compounds are a combination of one or more metallic elements (in light color) with one or more nonmetallic elements (in dark color).
Glasses: atomic-scale structure of (a) a ceramic (crystalline) and (b) a glass (noncrystalline)
Optical Properties of Ceramic are controlled by “Grain Structure” Grain Structure is a function of “Solidification” processing!
Polymers are typically inexpensive and are characterized by ease of formation and adequate structural properties
Periodic table with the elements associated with commercial polymers in color
Composite Materials – oh so many combinations Fiber Glass Composite:
Thoughts about these “fundamental” Materials • Metals: • Strong, ductile • high thermal & electrical conductivity • opaque, reflective. • Ceramics: ionic bonding (refractory) – compounds of metallic & non-metallic elements (oxides, carbides, nitrides, sulfides) • Brittle, glassy, elastic • non-conducting (insulators) • Polymers/plastics: Covalent bonding sharing of e’s • Soft, ductile, low strength, low density • thermal & electrical insulators • Optically translucent or transparent.
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.
Properties depend on Structure (strength or hardness) (d) 30mm (c) (b) (a) 4mm 30mm 30mm But: 6 00 5 00 4 00 Hardness (BHN) 3 00 2 00 100 0.01 0.1 1 10 100 1000 Cooling Rate (ºC/s) And: Processing can change structure! (see above structure vs Cooling Rate)
Another Example: Rolling of Steel • At h1, L1 • low UTS • low YS • high ductility • round grains • At h2, L2 • high UTS • high YS • low ductility • elongated grains Structure determines Properties but Processing determines Structure!
6 Cu + 3.32 at%Ni 5 4 Cu + 2.16 at%Ni deformed Cu + 1.12 at%Ni Resistivity,r 3 (10-8 Ohm-m) Cu + 1.12 at%Ni 2 1 “Pure” Cu 0 -200 -100 0 T (°C) Electrical Properties (of Copper): • Electrical Resistivity of Copper is affected by: • Contaminate level • Degree of deformation • Operating temperature Adapted from Fig. 18.8, Callister 7e. (Fig. 18.8 adapted from: J.O. Linde, Ann Physik5, 219 (1932); and C.A. Wert and R.M. Thomson, Physics of Solids, 2nd edition, McGraw-Hill Company, New York, 1970.)
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.)
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.)
-8 10 “as-is” “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.)
Example of Materials Engineering Work – Hip Implant • With age or certain illnesses joints deteriorate. Particularly those with large loads (such as hip). Adapted from Fig. 22.25, Callister 7e.
Example – Hip Implant • Requirements • mechanical strength (many cycles) • good lubricity • biocompatibility Adapted from Fig. 22.24, Callister 7e.
Example – Hip Implant Adapted from Fig. 22.24, Callister 7e.
Solution – Hip Implant Acetabular Cup and Liner • Key Problems to overcome: • fixation agent to hold acetabular cup • cup lubrication material • femoral stem – fixing agent (“glue”) • must avoid any debris in cup • Must hold up in body chemistry • Must be strong yet flexible Ball Femoral Stem
Course Goal is to make you aware of the importance of Material Selection by: • Using the right material for the job. one that is most economical and “Greenest” when life cycle usage is considered • Understanding the relation between properties, structure, and processing. • Recognizing new design opportunities offered by materials selection.