Corrosion behaviors of aluminum alloys in simulated SO₂ pollute atmosphere

The corrosion behaviors of aluminum alloys 1060, 2A12 and 7A04 in two different experimental conditions were investigated by scanning electron microscope (SEM), energy dispersive X-ray detection (EDX), Fourier transform infrared(FTIR), X-ray diffraction (XRD) and mass gain method in simulated 50 ppm SO₂ pollute atmosphere. The mechanical capability of experimental materials under different corrosion time was tested. The results show that the corrosion product increases with testing hours prolonging, mass gain of corrosion product adding and according with exponential attenuation rule as Δm/A=B+Dexp(-t/k), strength and elongation percentage declining. Surface observation showed that corrosion product was agglomerate and accidented, extending forth. The corrosion product of aluminum alloys in simulated 50 ppm SO₂ atmosphere was little and composed of alumina and aluminum sulfate. But the corrosion product of aluminum alloys on the surface of 70 μg·cm^-2 sodium chloride was more in simulated 50 ppm SO₂ atmosphere, mass gain of corrosion product adding more, strength and elongation percentage declining more greatly, corrosion product made up of alumina, aluminum sulfate hydrate and aluminum chloride.