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BMayer@ChabotCollege.edu ENGR-45_Lec-01_Intro.ppt 1 Bruce Mayer, PE Engineering-45: Materials of Engineering Bruce Mayer, PE Licensed Electrical & Mechanical Engineer BMayer@ChabotCollege.edu Engineering 45 Materials of Engineering - Introduction -
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu ENGR-45_Lec-01_Intro.ppt 4 Bruce Mayer, PE Engineering-45: Materials of Engineering The Evolution of Materials
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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 G10380 + w/ Pearlite
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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)
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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.
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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.
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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 !
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BMayer@ChabotCollege.edu 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)
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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
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BMayer@ChabotCollege.edu 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, 2004. 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.
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BMayer@ChabotCollege.edu 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 http://www.almaden.ibm.com/st/info/studen topps/nsfstudent/NSFapplic.html
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