Metal alloys

Metal

Good conductors heat & elec
Malleable
Ductile
Lustrous
High melt, boil
High densities

Metallic bond

Electrostatic attraction btwn positive ions + delocalised electrons.

Metal atoms readily loose their loosely held electrons, forming a sea of delocalised electrons around a crystal lattice of positive ions

Alloying
-harder
-less malleable
-poorer conductors than their pure form

-prepare by melt metal together, cool down → new substance

Formed by mixing a metal w/other metals
-sometimes use non metal to form (carbon, silicon)

Work hardening

Rearrangement of atoms into groups

Hammering/working cold metals
→ rearrangement of atoms

Harder, more brittle

Annealing

Heating metal to moderate temp → cool down slowly

Softer, more ductile
Larger groups of metals form

Quenching

Heating metal to moderate temp → cool down quickly

Harder, more brittle
Tiny groups of metals form

Tempering

Quenched metals = warm again at low temp → cool down slowly

Reduce brittle but keep hard
Medium sized groups of metals form