ch. 12 1.3-4 students per table 2.workbook & textbook 3.pencil / pen 4.start when quiet
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Ch. 12
1. 3-4 students per table
2. Workbook & Textbook
3. Pencil / Pen
4. Start when quiet
Ch. 12: Categories of Materials1. Wood & Modified Wood
2. Ceramics
3. Metals & Alloys
4. Plastics
5. Composites
Text / Work Books
Text Book – p. 391
Work Book - p. 201
• Copy the following definitions
WOOD
• Is a material obtained by harvesting and processing trees (p. 390)
MODIFIED WOOD
• Is treated wood or a material made from wood mixed with other substances
A CERAMIC
• Is a solid material obtained by heating inorganic matter containing various compounds, usually oxides.
A METAL
• Is a material extracted from a mineral ore.
• Aluminum• Chromium• Copper• Iron• Magnesium• Nickel• Tin• Zinc
AN ALLOY
• Is a mixture of a metal with one or more other substances.
Ferrous vs. Nonferrous
• Cast Iron• Steel
• Aluminium Alloys• Brass• Bronze
STEEL HEAT TREATMENTS
• Are methods of enhancing certain mechanical properties of steel through periods of heating.
WOOD vs. MODIFIED WOOD:
WOOD MODIFIED WOOD
Properties
• Species of trees• Speed of growth• Water content• Hardness, elasticity and
resilience• Low thermal
• Low electrical• Easy to shape &
assemble • Colors and shapes• Lightness
1. SPECIES OF TREESHARDWOOD SOFT WOOD
2. SPEED OF GROWTH
HEARTWOOD
SAPWOOD
3. WATER CONTENT
4. HARDNESS, ELASTICITY, RESILIENCE & TOUGHNESS
5. LOW THERMAL & ELECTRICAL CONDUCTIVITY
6. EASY TO SHAPE & ASSEMBLE
7. COLOURS & SHADES
8. LIGHTNESS
Degradation
• Fungi• Insect• Microorganism
Pine Beetle
PROTECTION
PRESSURE TREATING ROASTING
Chromated Copper Arsenate (CCA)
Maple
CERAMICS
Properties
• Low electrical conductivity
• High degree of hardness• Low thermal
conductivity
• Resistant to corrosion• Mechanical parts
1. LOW ELECTRICAL CONDUCTIVITY
2. HIGH DEGREE OF HARDNESS
3. LOW THERMAL CONDUCTIVITY
4. RESISTANT TO CORROSION
5. MECHANICAL PARTS
CERAMICS:Degradation
• ACIDS – sulphuric acid
• BASE – calcium hydroxide
• THERMAL SHOCK
CERAMICS:Protection
• AVOID…
• ACIDS – sulphuric acid
• BASE – calcium hydroxide
• THERMAL SHOCK
METALS & ALLOYS:
Properties
• Good thermal and electrical conductivity• Ductile• Malleable
1. Good thermal and electrical conductivity
2. Ductile
3. Malleable
METALS & ALLOYS: Degradation
OXIDATION = Corrosion
METALS & ALLOYS:
Protection
• Metallic Coating• Steel Heat Treatments
METALLIC COATINGS
EnamelGalvanizedChrome
STEEL HEAT TREATMENTS:Quench Hardening
APPENDIX 5 (p. 531)
PLASTIC & COMPOSITES
• Workbook p. 205
• Textbook p. 397
A PLASTIC
• Is a material made of polymers, to which other substances may be added to obtain certain desirable properties (p. 397)
Polymer Structure
A THERMOPLASTIC
• Is a plastic that becomes soft enough when heated to be molded or remolded and that hardens enough when cooled to hold its shape
Thermoplastic Products
A THERMOSETTING PLASTIC
• Is a plastic that remains permanently hard, even when heated
Thermosetting Products
A COMPOSITE
• Is formed by combining materials from different categories to obtain a material with enhanced properties.
Carbon Fiber
APPENDIX 5 - (p. 530)
Wood, modified wood, ceramics, metals and alloys lab
1. Work with table groups
2. Write ALL names on hand-out
3. Hand in at the end of lab
Homework
• Workbook - p. 201-208
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