Copper thermite can be prepared using either copper(I) oxide (CuO, red) or copper(II) oxide (CuO, black). The burn rate tends to be very fast and the melting point of copper is relatively low, so the reaction produces a significant amount of molten copper in a very short time. Copper(II) thermite reactions can be so fast that it can be considered a type of flash powder. An explosion can occur, which sends a spray of copper drops to considerable distances.
Oxygen-balanced mixture has theoretical maximum density of 5.109 g/cm, adiabatic flame temperature 2843 K (phase transitions included) with the aluminium oxide being molten and copper in both liquid and gaseous form; 343 g of copper vapor per kg of this thermite are produced. The energy content is 974 cal/g.
Copper(I) thermite has industrial uses in e.g., welding of thick copper conductors (cadwelding). This kind of welding is being evaluated also for cable splicing on the US Navy fleet, for use in high-current systems, e.g., electric propulsion.
Oxygen balanced mixture has theoretical maximum density of 5.280 g/cm, adiabatic flame temperature 2843 K (phase transitions included) with the aluminium oxide being molten and copper in both liquid and gaseous form; 77.6 g of copper vapor per kg of this thermite are produced. The energy content is 575.5 cal/g.