ENGR-45_Lec-01_Intro.ppt 1 Bruce Mayer, PE Engineering-45: Materials of Engineering Bruce Mayer, PE Licensed Electrical & Mechanical Engineer Engineering 45 Materials of Engineering - Introduction -

ENGR-45_Lec-01_Intro.ppt 2 Bruce Mayer, PE Engineering-45: Materials of Engineering Course Goals Summarized  Use the right material for the job i.e.; Materials Application  Understand the relation between PROPERTIES, STRUCTURE, and PROCESSING i.e.; Materials Science & Engineering  Recognize new design opportunities offered by materials selection i.e.; Physical-Design Innovation

ENGR-45_Lec-01_Intro.ppt 3 Bruce Mayer, PE Engineering-45: Materials of Engineering Class Q: Materials Engineering & Technology → What is it?  Investigating the Structures & Properties of Materials and Correlating these with the Design or Engineering or Technology Objectives

ENGR-45_Lec-01_Intro.ppt 4 Bruce Mayer, PE Engineering-45: Materials of Engineering The Evolution of Materials

ENGR-45_Lec-01_Intro.ppt 5 Bruce Mayer, PE Engineering-45: Materials of Engineering Materials Science & Engineering  Materials are ENGINEERED Structures Not Black Boxes  Basic Material Structure Has Many Dimensions

ENGR-45_Lec-01_Intro.ppt 6 Bruce Mayer, PE Engineering-45: Materials of Engineering Structure, Processing, & Properties  PROPERTIES depend on STRUCTURE e.g.; The HARDNESS vs STRUCTURE of Steel Hardness (BHN)  PROCESSING can change STRUCTURE e.g., STRUCTURE vs Cooling-Rate for Steel Tempered Martensite UNtempered Martensite Ferrite + Cementite G w/ Pearlite

ENGR-45_Lec-01_Intro.ppt 7 Bruce Mayer, PE Engineering-45: Materials of Engineering Classes of Materials  From Chem1A Recall The Periodic Table of Elements Metals Ceramics Polymers SemiConductors

ENGR-45_Lec-01_Intro.ppt 8 Bruce Mayer, PE Engineering-45: Materials of Engineering Metals  May be Pure or Compounds (Alloys) Along with Polymers The Most Common Everyday Material Typically from the 1 st Row of Transition Metals in Periodic Table (Fe, Cu, Ni, etc.) Have LARGE Numbers of NonBound Electrons –Makes them Good Electrical & Thermal CONDUCTORS Strong but Deformable (Ductile)

ENGR-45_Lec-01_Intro.ppt 9 Bruce Mayer, PE Engineering-45: Materials of Engineering Ceramics  Basic Composition is the MINERAL Form of a Metal Very Few Metals Exist in PURE Form in Nature –Most That Do are Very Rare, e.g., Gold  Ceramics are Compounds of Metals and Oxygen → Oxides (most Ceramics) Carbon → Carbides Nitrogen → Nitrides

ENGR-45_Lec-01_Intro.ppt 10 Bruce Mayer, PE Engineering-45: Materials of Engineering Ceramics cont.  Some Typical Properties HARD & BRITTLE HIGHEST Temperature Resistance –Thoria (Thorium Oxide) Max Temp  3000 K Llttle Temperature-SHOCK Resistance Corrosion Resistant Electrically Resistive (Insulative) Difficult to Join –Do Not Weld

ENGR-45_Lec-01_Intro.ppt 11 Bruce Mayer, PE Engineering-45: Materials of Engineering Polymers  Many ChemUnits MER  A Basic Chemical Unit POLY  Many  Chemical Compounds composed of, in VAST Majority, CARBON & HYDROGEN Modified by the Presence of Other Elements –O, Si, F, Cl, N, many others  Commonly Referred to as PLASTIC and/or (synthetic) RUBBER

ENGR-45_Lec-01_Intro.ppt 12 Bruce Mayer, PE Engineering-45: Materials of Engineering Polymers cont.  Some Typical Properties Very LightWeight Very Corrosion Resistant –Best of ANY Class of Material Little, if any, Hi/Lo Temperature Resistance Little Structural Strength Very Deformable (ductile/flexible) Lowest $-Cost:Volume Ratio for Any Class of Material

ENGR-45_Lec-01_Intro.ppt 13 Bruce Mayer, PE Engineering-45: Materials of Engineering SemiConductors  May be made CONDUCTIVE or INSULATIVE (or Something in- between) by the Addition of Miniscule Amounts of IMPURITIES Current Techniques Allow Precise Control over the AMOUNT and LOCATION of the Impurities  Semiconductors are Very Important Electronic Device Materials

ENGR-45_Lec-01_Intro.ppt 14 Bruce Mayer, PE Engineering-45: Materials of Engineering Semiconductors cont.  Most SOLID STATE (no moving parts) Electronic Devices are Semiconductors  Major applications for Semi Transistors Voltage Amplifiers On/Off switches  Additional Advantage: Semiconductor Electronic Devices can be constructed at Extremely SMALL Scales  SILICON is the Most Widely Used

ENGR-45_Lec-01_Intro.ppt 15 Bruce Mayer, PE Engineering-45: Materials of Engineering Composites  Materials that Consist of More than One Material Type Goal is to Combine the Best Features of Multiple Materials  Some Examples FiberGlass = Glass (ceramic) + Polymer –Strength + Flexibilty ReInforced Concrete = Steel + Concrete –Tension-Strength + Compression-Strength

ENGR-45_Lec-01_Intro.ppt 16 Bruce Mayer, PE Engineering-45: Materials of Engineering BioMaterials  Defined as Those Materials Which Are compatible with Human Tissue Classic Example = Stainless Steels used For Bone repair (Screws, Staples, Plates, Hip-Joints)  At least a few of ALL other Classes of Materials are BioCompatible Including Silicon

ENGR-45_Lec-01_Intro.ppt 17 Bruce Mayer, PE Engineering-45: Materials of Engineering Smart Materials  Smart Materials  Materials That Can Sense Changes in the Environment and Respond with a Material Shape/Property Change Example: "smart" materials that can be attached to, or embedded in, structural systems –enable the structure to sense disturbances, process the information and through commands to actuators, to accomplish some beneficial reaction

ENGR-45_Lec-01_Intro.ppt 18 Bruce Mayer, PE Engineering-45: Materials of Engineering Smart Materials, cont.  Potential Applications – Structural Systems Machine Tools - Improve precision and increase productivity by controlling chatter Flexible robotics - enable faster motion with greater accuracy Photo-lithography - Enable the manufacture of smaller micro-electronic circuits by controlling vibration in the photo-lithography circuit printing process Biomechanical & Biomedical - artificial muscles, drug delivery systems and other assistive technologies Process Control - e. g., on/off shape control of solar reflectors or aerodynamic surfaces

ENGR-45_Lec-01_Intro.ppt 19 Bruce Mayer, PE Engineering-45: Materials of Engineering NanoTechnology  Most Materials are Statistical Devices i.e., Their Properties are the Average of a LARGE Number of Atoms or Molecules –A change in a Single NanoScale Particle does NOT affect Material Characteristics  NanoScale Materials, on the Other hand, are built ONE NanoParticle at a time Properties Can be PRECISELY Tailored

ENGR-45_Lec-01_Intro.ppt 20 Bruce Mayer, PE Engineering-45: Materials of Engineering Materials Application Chain Processing Structure Properties Performance Selection Field Application  SELECTION is the Critical Step for Physical-Design Engineers

ENGR-45_Lec-01_Intro.ppt 21 Bruce Mayer, PE Engineering-45: Materials of Engineering Materials Selection 1.Pick APPLICATION → Determine Required PROPERTIES Properties Mechanical Electrical Thermal Magnetic Optical Deteriorative Corrosion Wear Ageing UV exposure, etc.

ENGR-45_Lec-01_Intro.ppt 22 Bruce Mayer, PE Engineering-45: Materials of Engineering Materials Selection cont. 2.PROPERTIES → Identify candidate Material(s) Properties Follow COMPOSITION as Identified by CHEMICAL CONTENT STRUCTURE as Determined by Material-Formation Processing; e.g.: Amorphous vs PolyCrystalline vs FullyCrystalline Second (and perhaps Tertiary) Phases Type Quantity Size Distribution

ENGR-45_Lec-01_Intro.ppt 23 Bruce Mayer, PE Engineering-45: Materials of Engineering Materials Selection cont.2 3.MATERIAL → Identify PROCESSING to Obtain Required Structure, and Hence Properties Processing Changes STRUCTURE or SHAPE, but NOT Composition e.g.: Casting Sintering Thin Film Deposition (CVD, Sputtering, Evap, etc.) Forming or other Cold-Working Joining Annealing, Tempering, or other Heat Treatment Etc.

ENGR-45_Lec-01_Intro.ppt 24 Bruce Mayer, PE Engineering-45: Materials of Engineering Material Properties Property Stimulus Result Terms  Material performance depends on material properties

ENGR-45_Lec-01_Intro.ppt 25 Bruce Mayer, PE Engineering-45: Materials of Engineering Basic Material Properties General Weight:Density , kg/m 3 Expense:Cost/kg C m, $/kg Mechanical Stiffness:Young’s modulus E, GPa Strength:Elastic limit  y, MPa Fracture strength: Tensile strength  ts, MPa Brittleness: Fracture toughness K Ic, MPa·m 1/2 Thermal Expansion:Expansion coeff. , 1/K Conduction: Thermal conductivity, W/m·K Specific Heat (Capacity), c p or c v, J/kg·K Electrical Conductor? Insulator? Conductivity σ, S/m Dielectric Capacity, F/m Young’s modulus, E Elastic limit, Strain Stress  Ductile materials Brittle materials Young’s modulus, E Tensile (fracture) strength, Strain Stress    Thermal expansion Expansion coefficient,  Temperature, T Thermal strain  x T1T1 ToTo Q joules/sec Area A Thermal conduction Mechanical properties Thermal conductivity, (T 1 - T 0 )/x Heat flux, Q/A

ENGR-45_Lec-01_Intro.ppt 26 Bruce Mayer, PE Engineering-45: Materials of Engineering Mechanical Properties Example Stiff Strong Tough Light Not stiff enough (need bigger E) modulus of elasticity Not strong enough (need bigger  y ) yield strength Not tough enough (need bigger K Ic ) fracture toughness Too heavy (need lower  ) density All OK !

ENGR-45_Lec-01_Intro.ppt 27 Bruce Mayer, PE Engineering-45: Materials of Engineering Electrical Structure/Properties  Electrical Resistivity of Copper  Adding “impurity” atoms to Cu increases resistivity  Deforming Cu increases resistivity  Note: Resistivity, = 1/Conductivity Resistivity → ρ (Ω-m) Conductivity → σ (S/m)

ENGR-45_Lec-01_Intro.ppt 28 Bruce Mayer, PE Engineering-45: Materials of Engineering Thermal Structure/Properties  THERMAL Conductivity of Copper  Adding “impurity” atoms to Cu (zinc to make a BRASS) Decreases Thermal conductivity

ENGR-45_Lec-01_Intro.ppt 29 Bruce Mayer, PE Engineering-45: Materials of Engineering Magnetic Structure/Properties  Magnetic Permeability vs. Composition for Iron  Adding 3 atomic % Si makes Fe a Much BETTER magnetic recording medium

ENGR-45_Lec-01_Intro.ppt 30 Bruce Mayer, PE Engineering-45: Materials of Engineering Optical Structure/Properties  Aluminum Oxide Light Transmittance  may be transparent, translucent, or opaque depending on the material structure single crystal polycrystal: low porosity polycrystal: high porosity

ENGR-45_Lec-01_Intro.ppt 31 Bruce Mayer, PE Engineering-45: Materials of Engineering Deteriorative Structure/Properties  SaltWater and STRESS can Cause Cracks in Metals  Heat treatment: slows crack formation speed in salt-water exposed metal

ENGR-45_Lec-01_Intro.ppt 32 Bruce Mayer, PE Engineering-45: Materials of Engineering Materials Information for Design The goal of design: “To create products that perform their function effectively, safely, at acceptable cost” What do we need to know about materials to do this? More than just test data. Test Test data Data capture Stat/Math analysis Design data Successful applications $ Economic analysis and business case Selection of material and process Potential applications Characterization Selection and implementation © 2002, M.F. Ashby and D. Cebon

ENGR-45_Lec-01_Intro.ppt 33 Bruce Mayer, PE Engineering-45: Materials of Engineering Goals of Matls Engineering & Technology  Select the Best Material for the Job  If something goes wrong (“failure”) Understand Why Fix & Prevent  Understand Inter- Relationships of processing structure properties performance Structure Processing Properties Performance  Open new design opportunities with new materials

ENGR-45_Lec-01_Intro.ppt 34 Bruce Mayer, PE Engineering-45: Materials of Engineering WhiteBoard Work  Problem Summary Here List problem –Features –Constraints –Criteria –Goals

ENGR-45_Lec-01_Intro.ppt 35 Bruce Mayer, PE Engineering-45: Materials of Engineering IBM-Almaden Internship  Target Audience Projects and the program are designed for sophomores and juniors with majors in chemistry, physics, chemical engineering and related sciences  Program Details  Duration: 10 weeks, beginning June 7 or June 21,  Stipend: Students $4500 for 10 weeks (not bad...).  Eligibility: Undergraduate (pre-graduate school) standing, with preferably two years of chemistry. Requirements vary by project, but outstanding candidates at any level and technical major in science or engineering are encouraged to apply. Preference is given to chemistry, chemical engineering, and materials science majors. Participants must be citizens or permanent legal residents of the US.

ENGR-45_Lec-01_Intro.ppt 36 Bruce Mayer, PE Engineering-45: Materials of Engineering IBM-Almaden Internship  The BAD News → A Pretty Nasty Set of Application Documents Two App Forms Two Letters of Req –I can Help Personal Essay  For the Forms see topps/nsfstudent/NSFapplic.html