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 at the Beginning of the Finals Period Semi-Pop Quizzes and homework/Chapter Reviews (Ch 17 & 18) – (20% of your grade!) – note, additional homework (not to be collected) 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 for Engineering: an Introduction Our Text: Materials Science for Engineering: an Introduction  By Callister & Rethwisch 8th Edition, Wiley, 2010.

Materials Science and Engineering It all about the (raw) materials and how they are processed That is why we call it materials ENGINEERING Minor differences in Raw materials or processing parameters can mean major changes in the performance of the final material or product

Why the class? As ME/IE we are involved in design of products or processes When making up a design, what materials we use are critical (and driven by the function of the design) When investigating processes, minor changes can have a major impact on the results

Materials Science and Engineering The discipline of investigating the relationships that exist between the structures and properties (or performance) 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

Material Selection in Design Properties are a link between the fundamental issues of materials science and the practical challenges of materials engineering. (FromG. E. Dieter, in ASM Handbook,Vol. 20: Materials Selection and Design, ASM International, Materials Park, OH, 1997, p. 245.)

And Remember: Materials “Drive” our Society! Ages of “Man” and note, 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 and strong materials 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 …

A Timeline of Human Materials “Control”

And Formula One – the future of automotive is … http://www.autofieldguide.com/articles/050701.html

Looking At CG Iron Alloy Development (Processing):

Looking At CG Iron Alloy Development (Processing):

CG Structure – but with great care! Poor “Too Little” Good Structure 45KSI YS; 55KSI UTS Poor “Too Much”

Looking At CG Iron Alloy Development (Structures)

Looking At CG Iron Alloy Development (Results)

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)

Introduction, cont. Metals Ceramics Polymers Composites 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.

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, inelastic non-conducting (insulators) Polymers/plastics: Covalent bonding  sharing of e’s Soft, ductile, low strength, low density thermal & electrical insulators Optically translucent or transparent. Metals have high thermal & electrical conductivity because valence electrons are free to roam

Structural Steel (a fundamental engineered metal) in Use: The Golden Gate Bridge

Periodic Table of Elements: The Metals

Structural Ceramics

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:

The Materials Selection Process – as a part of design 1. Engineered Application will 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.

These so-called Ashby Charts are developed for comparing candidate materials considering many design factors Materials property chart with a view of relative materials performance. Here plots of elastic modulus and density data (on logarithmic scales) for various materials indicate that members of the different categories of structural materials tend to group together. (After M. F. Ashby, Materials Selection in Engineering Design, Pergamon Press, Inc., Elmsford, NY, 1992.)

Processing can change structure! (see above structure vs Cooling Rate) But: Properties depend on Structure (strength or hardness) (d) 30 mm 6 00 5 00 (c) 4 mm 4 00 (b) 30 mm (a) 30 mm 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!

Electrical Properties (of Copper): T (°C) -200 -100 Cu + 3.32 at%Ni Cu + 2.16 at%Ni deformed Cu + 1.12 at%Ni 1 2 3 4 5 6 Resistivity, r (10-8 Ohm-m) Cu + 1.12 at%Ni “Pure” Cu Electrical Resistivity of Copper is affected by: Contaminate level Degree of deformation Operating temperature from: J.O. Linde, Ann Physik 5, 219 (1932); and C.A. Wert and R.M. Thomson, Physics of Solids, 2nd edition, McGraw-Hill Company, New York, 1970.)

THERMAL Properties • Space Shuttle Tiles: • Thermal Conductivity --Silica fiber insulation offers low heat conduction. • Thermal Conductivity of Copper: --It decreases when you add zinc! Composition (wt% Zinc) Thermal Conductivity (W/m-K) 400 300 200 100 10 20 30 40 100 mm 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.) Courtesy of Lockheed Aerospace Ceramics Systems, Sunnyvale, CA)

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. Magnetic Field Magnetization Fe+3%Si Fe 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. J.U. Lemke, MRS Bulletin, Vol. XV, No. 3, p. 31, 1990

DETERIORATIVE Properties • Heat treatment: slows crack speed in salt water! • Stress & Saltwater... --causes cracks! “held at 160ºC for 1 hr before testing” increasing load crack speed (m/s) “as-is” 10 -10 -8 Alloy 7178 tested in saturated aqueous NaCl solution at 23ºC 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.) 4 mm --material: 7150-T651 Al "alloy" (Zn,Cu,Mg,Zr) G.H. Narayanan and A.G. Miller, Boeing Commercial Airplane Company. 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).

Example – Hip Implant Requirements mechanical strength (many cycles) good lubricity biocompatibility

Example – Hip Implant

Solution – Hip Implant Key Problems to overcome: 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

Often, material selection comes down to a tradeoff of cost vs Often, material selection comes down to a tradeoff of cost vs. design property

Course Goal is to make you aware of the importance of Material Selection by: Choosing the right material for the job -- one that is the most economical and “Greenest” when life cycle usage is considered. As designers we must consider “Sustainability” in our designs and material choices Understanding the relation between properties, structure, and processing. Recognizing new design opportunities offered by materials selection.