Examen de Tecnología 

WOOD

HARDWOODS:

  1. Decidous and drop leaves in winter.
  2. There are expensive.

Examples: Mahogany, elm and oak

SOFTWOODS:

  1. Fastest growing trees
  2. Keep they leaves in cold regions
  3. Are easy to woek because of that there are poor
  4. Examples: Pine and redwood

MAN-MADE BOARDS:

  1. This trees there are cut and glued to form boards.
  2. They are also difficult to join and require special fixings

TYPES:

PLYWOOD: It´s made up of layers of thin wood glued on the top of the other.

MDF: It´s made by chips of wood. It´s cheaper to work because the chips can separate.

CHIPBOARD: It´s made by small particles of wood and its very useful to make objects

METALS:

FERROUS:

There are made up of an alloy of iron an other element. The iron can to rust because of that this metals are painted, oiled and galvanise. There are magnetics.

NON FERROUS:

This metals are pured and not contain iron (aluminium, tin and copper); but there are precious metals (Silver, gold and paltinium)

PROPERTIES:

  1. Hard and strong
  2. Solids at room temperature
  3. Shyni luster when polished
  4. Good conductors of heat and electricity
  5. Dense
  6. Malleable and ductibiliy

ALLOYS:

A mixture of two or more elements, the major component is metal. Combining different elements to improve the metal.