Corrosion protection of titanium by pulsed plasma deposition of palladium

The potential of pulsed ion deposition of palladium, using several coating conditions, for the corrosion protection of titanium foil in 0.1 M H2SO4, 0 .1 M HNO3 and a mixture of equal volumes of the two acids at 80 degrees C h as been investigated by weight loss measurements, scanning electron microsc opy and Rutherford backscattering spectroscopy. The environments were selec ted to evaluate the possible application of the coated foil for the electro n-transparent window of the Electron Beam Dry Scrubber Process for clean-up of Rue gas. The resultant coated foil had significantly enhanced corrosion resistance compared with the untreated foil for all coating conditions. Ho wever, the coating material was susceptible to local or general detachment during immersion in acid, most noticeably in H2SO4. The detachment usually initiated at flaws in the coating and may be related to local generation of hydrogen, a stress-corrosion cracking process, or the presence of oxygen i n the coating. Nevertheless, exposed regions of underlying material were re sistant to corrosion due to a remaining layer of Ti-Pd alloy. (C) 2000 Else vier Science Ltd. All rights reserved.