Alloying additions of Ni to amorphous Al-Ti alloy and Mo to Al-Cr alloys and simultaneous addition of Ti and Cr to Al have been performed to improve the corrosion resistance of amorphous Al-Ti and Al-Cr alloy, which are not passivated in 1 M HCl. Mg addition to Al-Ti alloys was also performed expecting enrichment of Ti in the surface film caused by rapid dissolution of alloying constituents unnecessary for passivation. The amorphous Al-Ti-Ni, Al-Cr-Ti and Al-Cr-Mo alloys were passivated spontaneously even in 1 M HCl solution and showed higher pitting potentials than those of Al-Ti and Al-Cr binary alloys. The addition of relatively small amount of Mg to Al-Ti alloys increased the pitting potential of Al-Ti alloys. X-ray photoelectron spectroscopy (XPS) measurement allowed to correlate the protective ability of the passive films to the stability of Cr or Ti enriched surface layer of the passive films.
展开▼
