Materials

Materials

Technical materials
1. Is the name given to all materials used to build objects that are obtained from raw materials
2. Raw materials
  1. Obtained directly from nature
    1. Wool
    2. Wood
    3. Marble
  2. Natural materials
    1. Raw materials are refined or prepared to obtain natural materials
      1. Wood
      2. Wool
      3. Marble
    2. Processed materials
      1. By processing natural materials, we can obtain other types of materials
      2. Technical material can be both natural or processed
        Woods
        Metals
        Plastics
        Textiles
        Construction materials
Properties
1. Each material has certain properties that make it suited to a certain use
  1. Bridge
    1. Strong material
  2. Sculpture
    1. Attractive material
  3. Aeroplane
    1. Lightweight material
  4. Toy
    1. Non-toxic material
2. Basic properties
  1. Sensory properties
    1. Related to our senses
    2. Colour
    3. Feel
    4. Texture
    5. Brightness
    6. Transparency
  2. Mechanical properties
    1. Related to the response of the material to the forces that act on them
    2. Hard (difficult to scratch)
      1. Soft (scratch easily)
    3. Tough (can withstand impact)
      1. Brittle (cannot withstand impact)
    4. Elastic (can return to their original form)
      1. Plastic (stay deformed)
    5. Malleable (can easly be flattened into sheets)
      1. Ductile (can easily be shaped into threads or wires)
  3. Physical properties
    1. Related to the response of the materials to physical phenomena (electricity, magnetism, temperature...)
    2. Materials can be
      1. Conductors
        Electrical conductor
        Copper
        Thermal conductor
        Metals
        Sound conductor
        Glass
      2. Insulators
        Electrical insulator
        Plastic
        Thermal insulator
        Wood
        Sound insulator
        Cork
3. Other properties
  1. Environmental properties
    1. Toxicity
Wood
1. Wood is the solid, rigid part found underneath the bark of tree trunks
  1. Properties
    1. Tough material
    2. Insulator (heat and electricity)
    3. Conductor (sound)
    4. Resistant
    5. Porous
    6. Are some properties problematic?
      1. Properties of a material are considered advantageous for une project but disadvantageous for another
2. How we obtain wood
  1. 1. Felling
    1. 2. Debarking
      1. 3. Transport to the sawmill
        4. Sawing for end use
        5. Drying
        6. Cleaning, planing and sanding
        7. Treatments and finishes
3. Before we can use wood, it must be prepared or refined
4. Types of wood
  1. Softwoods
    1. Comes from coniferous trees
      1. Pine
      2. Fir
      3. Poplar
    2. These woods are
      1. Easy to work with
      2. Cheap
      3. Uniform quality
  2. Hardwoods
    1. Comes from deciduous trees
      1. Oak
      2. Beech
      3. Chestnut
    2. These woods are
      1. More expensive
      2. Difficult to work
      3. Better-quality finish
5. Wood products
  1. We usually work with wood derivatives in the workshop
    1. Plywood
      1. Thin wood layers
    2. Chipboard
      1. Wood chips
    3. Paper
      1. Wood and plant fibres
    4. Cardboard
      1. Several layers of paper
    5. Cork
      1. Bark of the cork oak
6. Does using wood have an environmental impact?
  1. Wood is a biodegradable material
  2. Problems
    1. Indiscriminate felling of trees
      1. Deforestation
      2. Soil erosion
      3. Unbalanced ecosystems
    2. The pollution
      1. Caused by the chemical processes
  3. We can reuse wood
    1. Use both sides of the sheet
Metals
1. Are hard materials and good conductors of heat, electricity and sound
  1. They expand and contract with temperature, oxidise easily and are cold to the touch
    1. Some metals have magnetic properties
2. We extract metals from minerals
  1. Part of the mineral that we obtain metal
    1. Ore
  2. The rest of the mineral
    1. Gangue
3. We usually find metals as alloys and not in their pure form
  1. An alloy is a mixture of two or more metals, or of a metal and non-metallic components
    1. Phosphorus
    2. Carbon
    3. Silicon
4. Classifying metals
  1. Ferrous metals (contain mainly iron)
    1. Depending on their percentage of carbon
      1. Iron
        Less than 0.1 % carbon
        Soft, ductile and malleable
        Rusts easily
        Very brittle
      2. Steel
        Made mainly from iron, with 0.1 % to 2% carbon
        Hard, very durable and economical metal
        Used in industry
      3. Cast iron
        Made from iron and 2 % to 6.67 % carbon
        Hard but brittle
        Used in the manufacture of engines
  2. Non-ferrous metals
    1. Copper
      1. Bright, red-coloured metal
      2. Used since ancient times to make ornaments, coins and even weapons
      3. Good conductor of heat and electricity
    2. Tin
      1. Silver-coloured shiny metal
      2. Very resistant to corrosion and very ductile and malleable
      3. When it is heated to temperatures above 400 °C, it turns to liquid
    3. Aluminium
      1. Is a shiny, white, cheap and easy to recycle metal
      2. Very lightweight, a good conductor of heat and electricity
      3. It is non-toxic so it is used in food packaging
    4. Zinc
      1. Is bluish-white in colour and one of the least common metals
      2. Resistant to corrosion and oxidation
      3. It is often used to coat and protect other metals (mainly iron and steel)
    5. Other non-ferrous metals
      1. There are many metals with a wide variety of uses
5. Does using metals have an environmental impact?
  1. The mining of ore affects the landscape, produces noise and dust, releases gases and destroys habitats
  2. When the ore is processed to obtain metal, gases are formed that release heavy metals (cadmium, etc.) into the atmosphere. These metals pollute the air and water and can have carcinogenic effects on humans
  3. In processes to obtain steel, a lot of CO2 is released. CO2 is the gas responsible for the greenhouse effect
  4. We can reuse metals
    1. Recycling metallic products saves energy

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	Criado por IAGO DELCAMP BLAZQUEZ aproximadamente 3 anos atrás