Corrosion of a zinc-aluminium-copper alloy by fluorine gas

Corrosion of a commercial two-phase eutectoid zinc-aluminium alloy modified by 2% Cu (Zinalco(TM)) was performed at high temperature in a dry fluorine environment. This environment was kept at a pressure of 10(3) mbar for 100 and 300 h. The exposed samples were studied by resonant nuclear reaction, Auger electron spectroscopy, scanning electron microscopy and X-ray diffraction. The Knoop micro-hardness of the samples was measured before and after the exposure. Intergranular corrosion of the zinc-rich phase that tends to consume the material is observed, while the aluminium bonds to the fluorine forming a superficial AlF3 compound.