Q:
What are the definitions of
"Engineered Materials?"




A:
    METALS:

  • Any one (or combination thereof) of chemical
    elements such as gold, silver, iron, aluminum.

  • Metals have a lustrous surface and are
    good conductors of heat and electricity.

  • Metals tend to be ductile and malleable.

  • Mixtures of metals are called Alloys.


    CERAMICS:

  • Non-metallic, inorganic materials.

  • Originally considered to be oxides; from the Greek
    keramos for burnt earth, the traditional ceramics
    were clays.

  • Modern ceramics can be carbides, borides, etc., or
    can be based on non-metallic elements such as C.

  • Certain ceramics can be amorphous/non-crystalline,
    and are termed "glasses".


  • POLYMERS:

  • From the Greek, poly, meaning many and meros,
    meaning part, polymers are organic materials consisting
    of chains of molecules containing carbon. Polymer
    molecules are comprised of many simpler molecules
    (the "mers") strung together.


    SEMICONDUCTORS:

  • Materials such as Si and Ge, whose electrical
    conductivities are midway between metals and ceramics.

  • Also called "semi-metals."


    COMPOSITES:

  • Materials that are comprised of various parts.

  • Physical mixtures of two or more materials.

  • Wood and Rock are natural composites, whereas
    concrete is a man-made (engineered) composite.