Materials Sciences International Masters Programme in Biomedical Engineering Magnesium Innovations Center (MagIC) GKSS Forschungszentrum Geesthacht GmbH Dr.-Ing. Norbert Hort norbert.hort@gkss.de
Contents About me Introduction Structure of Materials Atoms and Bonds Crystal Lattices Multiphase Materials Properties Physical Properties Mechanical Properties Corrosion and Oxidation Friction and Wear Fatigue Fracture Materials Metals Polymers Ceramics Glasses Composites Materials Testing Materials Selection Page 2
Introduction About myself Dr.-Ing. Norbert Hort norbert.hort@gkss.de Tel: 04152-871905 GKSS Forschungszentrum Geesthacht GmbH Max-Planck-Str. 1 21502 Geesthacht Transparencies etc. ftp://ftp.gkss.de/pub/hort Important dates Acknowledgements Prof. Dr.-Ing. K.U. Kainer Prof. Dr.-Ing. O. Jacobs Dates 05.10. 12.10. 19.10. 09.11. 16.11. 23.11. 30.11. No lectures on: 26.10. 02.11. 21.12. 07.12. 14.12. 11.01. 18.01. 25.01. 01.02. Page 1
GKSS Page 2
GKSS 15 National Centres Environmental and Earth System Research Key Technologies Research for the Benefit of Human Health Energy Research Research of Aviation and Space Structure of Matter Page 3
GKSS Light-weight metals and polymers for transport and energy Materials for separation technology Materials research with neutrons (FRG1) and photons (HARWI) Coastal research Geesthacht, Staff 695 Teltow-Seehof, Staff 55 Regenerative medicine Stimuli-sensitive polymers Page 4
Materials Science Introduction Magnesium Innovations Center (MagIC) GKSS Forschungszentrum Geesthacht GmbH Dr.-Ing. Norbert Hort norbert.hort@gkss.de
Literature WD Callister, Materials Science and Engineering, Wiley&Sons M Ashby, Engineering Materials 1+2, Butterworth&Heinemann DR Askeland, The Science and Engineering of Materials, Thomson Learning JF Shackelford, Introduction to Materials Science for Engineers, Macmillan W Schatt, Werkstoffwissenschaft, Springer-VDI E Hornbogen, Werkstoffe, Springer E Hornbogen, H Warlimont, Metallkunde, Springer O Jakob, Werkstoffkunde, Vogel HJ Bargel, G Schulze, Werkstoffkunde, Springer-VDI Page 2
Introduction What is materials science? Why should we know about it? Materials drive our society Stone Age Bronze Age Iron Age Now? Silicon Age? Polymer Age? Page 3
Nature - Application Jaw of an Antlion Head of Pliers Page 4
Nature - Application Part of a spine of a wasp Part of a rasp Page 5
Introduction enhanced service temperatures by ceramic coatings reliability of a CD depends on coloured functional inter-layer Page 6
Introduction restricted life time due to: corrosion fatigue creep aging wear... Page 7
Structure, Processing, & Properties Properties depend on structure ex: hardness vs structure of steel Hardness (BHN) 600 500 400 300 200 (a) 30 μm (b) 30 μm (c) 4 μm 100 0.01 0.1 1 10 100 1000 Cooling Rate (ºC/s) Processing can change structure ex: structure vs cooling rate of steel (d) 30 μm Page 8
Types of Materials Metals: Strong, ductile high thermal & electrical conductivity opaque, reflective. Polymers/plastics: Covalent bonding sharing of e s Soft, ductile, low strength, low density thermal & electrical insulators Optically translucent or transparent. Ceramics: ionic bonding (refractory) compounds of metallic & nonmetallic elements (oxides, carbides, nitrides, sulfides) Brittle, glassy, elastic non-conducting (insulators) Page 9
Material Groups Metals Semiconductors Conductive Polymers Superconductors Polymers Composites Silikon Ceramics Page 10
Properties Page 11
Properties Page 12
Properties Page 13
Properties Page 14
Properties Page 15
Multi-Materials Mix Page 16
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. Page 17
Electrical Electrical Resistivity of Copper: 6 Cu + 3.32 at%ni deformed Cu + 1.12 at%ni Cu + 2.16 at%ni Cu + 1.12 at%ni 5 4 3 2 1 0 Resistivity, ρ (10-8 Ohm-m) Pure Cu -200-100 0 T ( C) Adding impurity atoms to Cu increases resistivity. Deforming Cu increases resistivity. Page 18
Thermal Space Shuttle Tiles: --Silica fiber insulation offers low heat conduction. Thermal Conductivity of Copper: --It decreases when you add zinc! Thermal Conductivity (W/m-K) 400 300 200 100 0 0 10 20 30 40 Composition (wt% Zinc) 100μm Page 19
Magnetic Magnetic Storage: --Recording medium is magnetized by recording head. Magnetic Permeability vs. Composition: --Adding 3 atomic % Si makes Fe a better recording medium! Magnetization Magnetic Field Fe+3%Si Fe Page 20
Optical Transmittance: --Aluminum oxide may be transparent, translucent, or opaque depending on the material structure. single crystal polycrystal: low porosity polycrystal: high porosity Page 21
Detoriative Stress & Saltwater... --causes cracks! Heat treatment: slows crack speed in salt water! crack speed (m/s) 10-8 10-10 as-is held at 160ºC for 1 hr before testing Alloy 7178 tested in saturated aqueous NaCl solution at 23ºC increasing load --material: 7150-T651 Al "alloy" (Zn,Cu,Mg,Zr) 4 μm Page 22
Example Hip Implant With age or certain illnesses joints deteriorate. Particularly those with large loads (such as hip). Page 23
Example Hip Implant Requirements mechanical strength (many cycles) good lubricity biocompatibility Page 24
Example Hip Implant Page 25
Hip Implant Key problems to overcome fixation agent to hold acetabular cup Ball cup lubrication material femoral stem fixing agent ( glue ) must avoid any debris in cup Acetabular Cup and Liner Femoral Stem Materials: Titanium alloy Cobalt alloy UHMWPE* Page 26
Materials Science Materials Science investigates the relations between physical and technological properties of macroscopic materials (components) in relation to their micro-structure and to the influences of processing routes. Component Polycrystal Single crystal Atom [m] [mm] [μm] [nm] Example: The mechanical properties of a material are determined by Geometry and Microstructure amorphous crystalline Degree of ross-linkage Grain size, Dislocation density Page 27
Summary Course goals: Use the right material for the right job. Understand the relation between properties, structure, and processing. Recognize new design opportunities offered by materials selection. Page 28