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Aluminium (or aluminum in North American English) is a chemical element; ... (AlCl 3) has a layered polymeric structure below its melting point of 192.4 °C ...
melting point 302.9146 K (29.7646 °C) ... "Melting Points of Aluminum, Silver, Gold, Copper, and Platinum". Proceedings of the American Academy of Arts and Sciences.
The melting point (or, rarely, ... Many laboratory techniques exist for the determination of melting points. A Kofler bench is a metal strip with a temperature ...
Cast aluminium alloys yield cost-effective products due to the low melting point, although they generally have lower tensile strengths than wrought alloys. The most important cast aluminium alloy system is Al–Si, where the high levels of silicon (4–13%) contribute to give good casting characteristics. Aluminium alloys are widely used in ...
Aluminium oxide (or aluminium(III) oxide) is a chemical compound of aluminium and oxygen with the chemical formula Al 2 O 3. It is the most commonly occurring of several aluminium oxides, and specifically identified as aluminium oxide. It is commonly called alumina and may also be called aloxide, aloxite, or alundum in various forms and ...
Many trivalent metals are capable of forming alums. The general form of an alum is XY (SO 4) 2 · n H 2 O, where X is an alkali metal or ammonium, Y is a trivalent metal, and n often is 12. The most important example is chrome alum, KCr(SO 4) 2 ·12 H 2 O, a dark violet crystalline double sulfate of chromium and potassium, was used in tanning.
Although a molten aluminium salt could be used instead, aluminium oxide has a melting point of 2072 °C (3762°F) [4] so electrolysing it is impractical. In the Hall–Héroult process, alumina, Al 2 O 3, is dissolved in molten synthetic cryolite, Na 3 AlF 6, to lower its melting point for easier electrolysis. [1]
The melting point of aluminium oxide is 2050°C (2323K), much higher than pure aluminium's 658°C (931K). [6] This and the insulativity of aluminium oxide can make welding more difficult. In typical commercial aluminium anodizing processes, the aluminium oxide is grown down into the surface and out from the surface by equal amounts. [7]