Al/Cu sub(2)O Thermite Compatibility Studies by X-Ray Photoelectron and X-Ray Induced Auger Spectroscopy

The surface chemistry of Al/Cu sub(2)O thermite in powdered mixtures and in pressed pellets was studied before and after accelerated agings with x-ray photoelectron spectroscopy (XPS) and with x-ray induced Auger spectroscopy (XAES). The kinetic energies of the XPS or XAES signals were observed for Al 1s, Cu 2p sub(1/2), Cu 2p sub(3/2), Cu L-MM, O 1s, Al K-LL, C 1s and Cu 3s. The Al sub(2)O sub(3) film thicknesses on Al metal surfaces were deduced from signal intensity ratios of Al super(+3) and Al in XPS of Al 2s and from Al K-LL XAES signals. The oxide thicknesses on Al powders from the manufacturer were measured. Mixing Al with Cu sub(2)O at room temperature, to form the thermitic composition, induced oxidation of the Al and increased the oxide film thickness. Hot pressing of thermite powders at 425 degree C to form pellets was found to double the oxide layer. This oxide layer was found to protect the A1 fuel; further aging of these pellets at 180 degree C for several months showed a negligible change in composition and thickness of the surface oxide. The bulk of the pellet was found to be stable and of good quality.