ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 1 Bruce Mayer, PE Engineering-11: Engineering Design Bruce Mayer, PE Licensed Electrical & Mechanical Engineer Engineering 11 Materials Selection

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 2 Bruce Mayer, PE Engineering-11: Engineering Design Materials Selection at Config ? Formulation Customer Needs Customer requirements Importance weights Eng. characteristics House of Quality Eng. Design Spec’s Concept Design Abstract embodiment Physical principles Material Geometry Configuration Design

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 3 Bruce Mayer, PE Engineering-11: Engineering Design Matls & Manuf  Closely Linked Problem Formulation Detail Design Parametric Design Configuration Design Concept Design materials manufacturing processes

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 4 Bruce Mayer, PE Engineering-11: Engineering Design Matls & Manuf  Closely Linked Material Properties Manufacturing Processes COMPATIBLE materials & processes  e.g.; Ceramics can NOT be WELDED

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 5 Bruce Mayer, PE Engineering-11: Engineering Design Matls & Manuf  Closely Linked  e.g.; CAST Parts can NOT have SHARP Corners Manufacturing Processes Product Geometry CAPABLE Processes for the geometry

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 6 Bruce Mayer, PE Engineering-11: Engineering Design Matl↔Manf↔Geom  Function Material Properties Manufacturing Processes Product Geometry Product Function

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 7 Bruce Mayer, PE Engineering-11: Engineering Design Properties of Solid Materials  Mechanical: Characteristics of materials displayed when Forces or Moments are applied to them.  Physical: Characteristics of materials that relate to the interaction of materials with various forms of energy.  Chemical: Material characteristics that relate to the Material’s electron structure.  Dimensional: Size, shape, and finish

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 8 Bruce Mayer, PE Engineering-11: Engineering Design Material Properties Chemical Physical Mechanical Dimensional Composition Melting Point Tensile propertiesStandard Shapes Microstructure Thermal Toughness Standard Sizes Phases Magnetic DuctilitySurface Texture Grain Size Electrical FatigueStability Corrosion Optical HardnessMfg. Tolerances Crystallinity Acoustic Creep Molecular Weight Gravimetric Compression Flammability  One More ≡ $COST, $COST, $COST

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 9 Bruce Mayer, PE Engineering-11: Engineering Design Solid-Materials Family Tree CeramicsMetalsPlasticsComposites Materials Elastomers Thermosets Thermoplastics Non-ferrous Ferrous Sub-family See Also ENGR45

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 10 Bruce Mayer, PE Engineering-11: Engineering Design Solid-Materials Taxonomy Metals Materials Ferrous Sub-family Family Classes Cast iron Carbon steel Alloy steel Stainless steel

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 11 Bruce Mayer, PE Engineering-11: Engineering Design Metals Family Tree Non-ferrousFerrous (Mostly Iron) Metals aluminum brass bronze copper lead magnesium nickel tin titanium tungsten zinc cast iron carbon steel alloy steel stainless steel

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 12 Bruce Mayer, PE Engineering-11: Engineering Design Polymer (Plastics) Family Tree Elastomers Thermosets Thermoplastics Polymers butyl fluorocarbon neoprene nitrile polysulfide rubber silicone alkyd epoxy melamine phenolic polyester urethane ABS acetal acrylic nylon polycarbonate polyethylene polypropylene polystyrene vinyl

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 13 Bruce Mayer, PE Engineering-11: Engineering Design Ceramics & Composites Trees Ceramics alumina beryllia diamond magnesia Silicates Silica carbide Nitride Oxide zirconia carbon fiber ceramic matrix glass fiber Kevlar fiber metal matrix polymer matrix Composites

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 14 Bruce Mayer, PE Engineering-11: Engineering Design Material Family Comparison

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 15 Bruce Mayer, PE Engineering-11: Engineering Design Materials Selection Strategy prospective materials and processes screening rating rejected materials and processes best material(s) and processes functional? manufacturable? relative performance? feasible materials and processes

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 16 Bruce Mayer, PE Engineering-11: Engineering Design Materials Selection  The designer of any product, other than software, must be part of the material selection process.  Only occasionally will the exact grade of material be specified by the customer. Even then the designer must UNDERSTAND the material to be able to design the product.

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 17 Bruce Mayer, PE Engineering-11: Engineering Design Decisions, Decisions!  So many materials, so much information. How do we decide? How do we even begin to choose? –Metals are the DEFAULT as they have the widest variety of Manufacturing Processes  First we need to look at the function of the product Use PRODUCT ANALYSIS

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 18 Bruce Mayer, PE Engineering-11: Engineering Design Product Analysis  Just what it says – analyze the product! What does it do? How does it do it? Where does it do it? Who uses it? What should it cost?

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 19 Bruce Mayer, PE Engineering-11: Engineering Design Case Study  BiCycle  What is the function of a bike – obvious?  How does the function depend on the type of bike? Racing Touring Mountain Commuter Child’s

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 20 Bruce Mayer, PE Engineering-11: Engineering Design Case Study  BiCycle (2)  How is it made to be easily maintained?  What should it look like (colors etc.)?  What should it cost? Child’s Bike VS. Professional Racing Bike  How has it been made comfortable to ride?  How do the mechanical parts work and interact?

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 21 Bruce Mayer, PE Engineering-11: Engineering Design Component or System?  1 st problem is……. Is a BiCycle one component or a system of components working together?  e.g.; a one-piece Bracket is a component, a Cordless Screwdriver is a system.

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 22 Bruce Mayer, PE Engineering-11: Engineering Design System Analysis  When we analyze a system we need to break the system down into individual components and then analyze each one for the best Matl.  CordLess ScrewDriver BreakDown A Nice EXPLODED-View (Assembly) Drawing

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 23 Bruce Mayer, PE Engineering-11: Engineering Design System Analysis  BiCycle  The bike breaks down (Not Literally, we hope) into various parts: Frame & Forks Wheels & Brakes Seat & Peddles Gears & Chain Safety (reflectors) etc. 

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 24 Bruce Mayer, PE Engineering-11: Engineering Design System Analysis  BiCycle  Now need to look at the following for each part: Requirements (mechanical, ergonomic, aesthetic etc.) Function How many are going to be made? What manufacturing methods are we going to use?

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 25 Bruce Mayer, PE Engineering-11: Engineering Design Manufacturing InterDependency  YES!...We have to actually MAKE it!  This is a key question which has a HUGE influence on materials selection.  e.g., what materials could we use for the FRAME?

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 26 Bruce Mayer, PE Engineering-11: Engineering Design Frame Material Candidates  Steel Strong, stiff, HEAVY, Inexpensive, Easy to Join  Aluminum WEAKER, lighter, MORE EXPENSIVE than steel, Hard to Join  Composite (CFRP) strong, stiff, very light, but MOST EXPENSIVE

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 27 Bruce Mayer, PE Engineering-11: Engineering Design Bike Frame

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 28 Bruce Mayer, PE Engineering-11: Engineering Design Frame Joint Detail  A Critical Manufacturing Process Detail Weld? Braze? Shrink Fit? Other?

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 29 Bruce Mayer, PE Engineering-11: Engineering Design Where do I find Materials data?  Textbooks  Databooks  Manufacturer’s literature  Internet Sites Current Default –Most DataBooks are OnLine

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 30 Bruce Mayer, PE Engineering-11: Engineering Design Textbooks  Good for general information  Some have tables of properties  Not good for detailed specifications and properties.  A useful starting point

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 31 Bruce Mayer, PE Engineering-11: Engineering Design Databooks  One of the quickest sources of detailed information.  Usually contain grades and specifications as well as properties.  Small and perfectly formed – pocketbooks  Easy to navigate around

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 32 Bruce Mayer, PE Engineering-11: Engineering Design Manufacturer’s literature  Variable in quality and usefulness.  Often only cover their products.  Usually do not compare materials.  Can be biased.  Good for final selection before ordering.

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 33 Bruce Mayer, PE Engineering-11: Engineering Design InterNet Sites  Can be a real minefield.  Lots of poorly presented information.  Google searches bring up lots of SuperFluous info.  Hard to find technical information.  Best to use non-commercial sites.

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 34 Bruce Mayer, PE Engineering-11: Engineering Design MatWeb.com is VERY Good for Props

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 35 Bruce Mayer, PE Engineering-11: Engineering Design Materials Selection Charts  Allow easy visualization of properties  Show lots of different materials  Can be ‘drilled down’ to specifics  Show balances of properties e.g. strength vs cost  Ideal for a first ‘rough cut’ selection

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 36 Bruce Mayer, PE Engineering-11: Engineering Design TradeOff Weight & Stiffness

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 37 Bruce Mayer, PE Engineering-11: Engineering Design Modulus - Density Chart  Modulus spans 5 orders of magnitude 0.01 GPa for foams to 1000 GPa for diamond  The charts therefore use logarithmic scales, where twice the distance means ten times the property value.  This makes it possible to show the full range on one chart,

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 38 Bruce Mayer, PE Engineering-11: Engineering Design TradeOff Weight & Strength

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 39 Bruce Mayer, PE Engineering-11: Engineering Design TradeOff Insulation & Expansion

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 40 Bruce Mayer, PE Engineering-11: Engineering Design Summary  Matls Selection 1.Think about the design from ergonomic and functional viewpoint. 2.Decide on the materials to be used. 3.Choose suitable manufacturing processes that are also economic  Steps 2 & 3 may be iterative. Don’t forget the ……………  NextSlide

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 41 Bruce Mayer, PE Engineering-11: Engineering Design Bigger Picture (don’t forget)  Is the product PERFORMANCE driven or COST driven? This makes a huge difference when choosing materials. –Kid’s bike vs. Racing bike

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 42 Bruce Mayer, PE Engineering-11: Engineering Design Manufacturing Priority  Although we usually choose materials FIRST sometimes it is the SHAPE and PROCESS which is the limiting factor. e.g.; Complex HiVacuum Chambers almost always must be WELDED to form GasTight Seals –Limits Materials Selection to METALS

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 43 Bruce Mayer, PE Engineering-11: Engineering Design Summary  Materials Selection  Product function interdependence  Mechanical properties  Physical properties  Families, sub, classes of materials  TradeOff (Ashby) charts  Materials first approach  Process first approach

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 44 Bruce Mayer, PE Engineering-11: Engineering Design All Done for Today Another Ashby Chart

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 45 Bruce Mayer, PE Engineering-11: Engineering Design Bruce Mayer, PE Registered Electrical & Mechanical Engineer Engineering 11 Appendix

ENGR-11_Lec-08_Chp5_Materials_Selection.ppt 46 Bruce Mayer, PE Engineering-11: Engineering Design What is an Ashby Chart?  It’s a form of a picture that’s worth well more than a 1000 words for any engineering designer. Named for Prof. M. F.Ashby, this is a tool that’s less widely used than it should be.  The chart involves plotting “clouds” on a 2-axis plot, with different variables on each axis. Sounds simple, but the impact doesn’t hit you till you actually see them, as in this example from Granta above: