N. Murugesan, Rikito Murakami, S. Itoi, Kei Kamada, Takashi Hanada, Akihiro Yamaji, Satoshi Ishizawa, Masao Yoshino, Hiroki Sato, Shunsuke Kurosawa, Yuui Yokota, Akira Yoshikawa
In this study, we examined the corrosion resistance of Ru 57 Mo 14.25 W 23.75 Fe 5 , Ru 54 Mo 13.5 W 22.5 Fe 10 , and Ru 48 Mo 12 W 20 Fe 20 alloys in inorganic acids. The alloys were fabricated using the dewetting micro-pulling-down and plasma-melt stamping methods. Immersion tests in H 2 SO 4 at 300 °C for 24 h indicated that Ru-Mo-W-Fe alloys exhibit better corrosion resistance (<0.17 mm y −1 ), compared to conventional corrosion-resistant materials (>10 mm y −1 ). Immersion tests at 25 °C in 5% HCl for 72 h and at 100 °C in 50% HF for 24 h also indicated that Ru-Mo-W-Fe alloys are highly corrosion resistant. Electrochemical tests in 1 M HCl and 1 M H 2 SO 4 revealed an increase in the anodic current and the formation of a low charge transfer resistance passive layer corresponding to alloying Fe. XPS analysis revealed that the primary corrosion product formed during polarization of Ru-Mo-W-Fe alloys in 1 M H 2 SO 4 was WO 3 . Notably, WO 3 is kept passivated on pure W during the corrosion in H 2 SO 4 ; however, it is not kept passivated when present on Ru-Mo-W-Fe alloys.