Roman metallurgy the most important being bronze, an alloy of copper and tin. Alloys are mixtures of different metals created either by smelting or by forging. It is important to note that an ore does not necessarily constitute an alloy; ore is a collection of minerals and alloyed metals. As metallurgical technology developed (hammering, melting, smelting, roasting, cupellation, moulding, smithing, etc.), more metals were intentionally included in the metallurgical repertoire. By the height of the Roman Empire, metals in use included: Gold, Silver, Copper, Tin, Lead, Zinc, Iron, Mercury, Arsenic, Antimony (Healy 1978). As in the Bronze Age, metals were used based
2219 aluminium alloy toughness, is weldable and resistant to stress corrosion cracking, therefore it is widely used in supersonic aircraft skin and structural members. The Space Shuttle Standard Weight Tank was also fabricated from the 2219 alloy. Alternate designations include AlCu6Mn and A92219. It is described in the following standards: The alloy composition of 2219 aluminium is: 2219 aluminium alloy 2219 aluminium alloy is an alloy in the wrought aluminium-copper family (2000 or 2xxx series). It can be heat-treated to produce tempers with higher strength but lower ductility. The aluminium-copper alloys have high strength, but are generally less corrosion resistant and harder to