Materials, Properties, and Applications: Wood & Metals

Posted on Feb 6, 2025 in Geology

Materials and Raw Materials

Raw materials are resources obtained directly from nature without undergoing any transformation. The main ones are:

Air: Used in chemical reactions, lens manufacturing, and fertilizer production.
Water: Used in non-potable manufacturing, chemical reactions, lens production, and paper making.
Rocks and Minerals: Used to produce metals, glass, etc.
Petroleum: Used to obtain gasoline, diesel fuel, etc.
Vegetables: Provide fibers, resins, pigments, etc.
Animals: Used for silk, wool, leather, etc.

Transformation of Materials

To be used by humans, raw materials must be transformed through a series of processes into products.

Physicochemical Properties of Materials

Electrical Conductivity: A material’s ability to conduct electricity.
Thermal Conductivity: A material’s ability to transmit heat.
Dilation: The increase in volume of a material when the temperature increases.
Oxidation: A material’s ability to oxidize, reacting with oxygen in the air.
Solubility: The ease with which a material dissolves in a substance.
Mechanical Properties: A material’s resistance to stresses and strains.
Optical Properties: Behavior of materials in response to light.

Technological Properties

Plasticity: The ease with which some materials change shape without breaking.
Malleability: The ability of some metals to be formed into extended sheets.
Ductility: The ability of some metals to be formed into extended strings.
Solderability: The ease with which a metal can be joined to another by welding.
Fusibility: The ease or difficulty of a material to melt.

Mechanical Properties

Hardness: A material’s resistance to being scratched by another.
Tenacity and Fragility: Tenacity is a material’s resistance to breaking when struck. The opposite of tenacity is fragility.
Elasticity and Plasticity: Elasticity is a material’s ability to recover its shape when the effort ceases (e.g., rubber). Plasticity is the opposite of elasticity; the material deforms under stress and does not return to its original state when the stress is removed (e.g., plasticine).
Flexibility and Rigidity: Flexibility is a material’s ability to bend without breaking. The opposite is rigidity.

Solid Wood

Solid wood is a strong, durable material with multiple applications. However, it is an expensive material. The following tools are used for working with wood:

To draw lines perpendicular to the edges of wood pieces, a square and a bevel are very useful for marking.
To cut thin wood, a hacksaw and an electric fretsaw are used.
To make cuts, a backsaw or a miter box is used.
To drill, use an auger for fine wood, a hand drill for heavier timber, and a drill press for precise work.
Finishes are done with a rasp and sandpaper.

Wood Properties

Wood is a recyclable and biodegradable material. It consists of cellulose fibers with substances called lignin. Wood is tough and flexible, a thermal insulator, and an electrical insulator (when dry). Other properties include:

Color: Usually, dark woods are more resistant than light-colored woods.
Texture: Indicates the treatment needed.
Grain: Shows the color and direction of its fibers.
Density: Relates to weight and resistance.

Metallic Materials

Metallic materials are those that are basically composed of one or more metals, although they may include other non-metallic elements, like carbon. Of all the metallic materials, iron and its derivatives are particularly important in industry. These materials are called ferrous materials.

Metallic Materials Commonly Used in Workshops

These include steel, brass, cupronickel, copper, tin, and aluminum.

Copper: A bright red metal, a good conductor of heat and electricity, very ductile and malleable, easy to cut and bend, and very resistant to corrosion. It has multiple uses: coins, boilers, pipes, cables, etc.
Tin: Very resistant to air, easy to melt and work. It is malleable when cold but becomes brittle when hot. It is used in soldering and in the alloy to make bronze.