2. Classificationof Materials

posses particular native properties and function of their own

materials used to manufacture structural members of machines and buildings that absorb power loads

—> machanical properties determining parameters

• toughness

• stiffness

• resistance to wear

• corrosion resistance

• Metals

• Ceramics

• Polymers

• Glasses

• Composites

  
  

• high strength, ductile

• high thermal and electrical conductivity

• opaque, reflective

• high strength, brittle

• variable thermal & electrical conductivity

• colored, reflective

• soft, ductile, low strength, low density

• thermally & electrically insulating (mostly)

• optically transparent (could be)

• brittle, glassy

• thermally & electrically insulating (mostly)

• optically transparent (could be)

• electrical

• thermal

• optical

• mechanical

• magnetic

• Conductors

• semiconductors

• Insulators

• Dielectrics

• Conductors

• Insulators

• transparent

• opaque

• specific absorption - colour

• brittle

• ductile

• hard

• soft

• heavy/light

• diamagnetic

• paramagnetic

• ferromagnetic

property is inherent to the material itself,i.e relies on its chemistry, nature of the bond and crystalstructure

• Youngs Modulus

• Optical properties

based on the intrinsic properties butrelies on the microstructure of the material

• Fracture Toughness

• Magnetic hardness

• Function

• Shape

• Process

• Material

  
  

1. Raw materials

2. Primary shaping

3. secondary processes

4. Joining

5. Surface treatment

6. Finished product

• Casting methods: Sand, Die, Investment

• Molding methods: Injection, Compression, Blow molding

• Deformation methods: Rolling, Forging, Drawing

• Powder methods: Sintering, HIPing, Slip casting

• Composite forming: Hand lay-up

• Special methods: Rapid protoype

• Machining: Cut, turn, grind

• Heat treat: Quench, age-harden

• Fastening, Riveting

• Welding, Heat bonding

• Snap fits, Friction bond

• Adhesives, Cements

• Polishing, Texxturing

• Plating, Metallizing

• Anodize, Chromizing

• Painting, printing

• Elastic modulus E: Resistance to elastic deformation(„stiffness“)

• Yield strength σy: How far a material can be deformedelastically („ductility“)

• Tensile strength σts: The amount a material stretches beforeit breaks („strength“)

• Fracture toughness K(1c): How easy a material breaks („tough –brittle“)

• Density ρ: How heavy a material defined volume ofa material is („light – heavy“)

• 2-dimensional bubble charts or ASHBY-plots compare two properties with each other, therefore separating families of materials distinctly

• basis idea is to plot 2 material properties in a (double) logarithmic scale

• material indices and selection guidelines as well as basic laws of physics can be included

transport of electrons/holes in asolid matrix

Transport of charged atoms (ions)in a solid matrix

• bonding properties,

• electronic structure

• defect formation

• Technically important ion conductorsare for H+, O 2-, Li+

• Ion conductors are ceramics,polymers or liquids

• The best ion conductivities are in therange of low-conducting (electronic) semi-conductors

• Technically important electron conductorsare metals, semiconductors,and specifically designed polymersor ceramics/glasses (TCOs)

• Electron conductors need free (mobile)electrons or holes (non-occupied electronstates

• The best electron conductivities are inobtained for metals and highly doped semiconductors

• Metals/semiconductors are characterized by decreased/increased electron conductivities at increased temperatures