Popis: |
An experiment was undertaken to study the oxidation of liquid superpure aluminium (SP-Al) and alloys containing Mg, Si, Cu and Fe. The alloys were held at 750 °C, for a number of different holding times up to 7 hours. A comparison of the oxidation of SP-Al (superpure) held at 700 °C, 750 °C and 800 °C for 3 hours was also carried out. On observation of the samples using SEM and EDX the oxides of SP-Al and the Al-Mg alloy grew quickly (by 5.8 μm after 7 hours and 2 μm after 1 hour, respectively), in a manner reported in the literature. The other alloys had reduced rates of oxide growth, with thickness changes between 30 nm and 0.25 μm for Al-Si, Al-Cu and Al‑Fe alloys. Changes in holding temperature showed a thick oxide on samples held at 850 °C for 3 hours. |