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