Effect of Cryogenic Thermal Cycling on Tribocorrosion Performance of Fe-Based Bulk Amorphous Alloy in 3.5 Pct NaCl Solution

The effects of cryogenic thermal cycling on the tribocorrosion behavior of Fe41Co7Cr15Mo14C15B6Y2 bulk amorphous alloy were studied in 3.5 pct NaCl solution. The relaxation enthalpy and fracture toughness increased by the cryogenic thermal cycling treatment while the hardness decreased. Moreover, the corrosion resistance enhanced with the formation of more stable passive film. Accordingly, when sliding against ZrO2 ball under 10 N load in 3.5 pct NaCl solution, the corrosive wear rates of Fe-based bulk amorphous alloys generally decreased with the increase of the number of cryogenic thermal cycles. After 60-cycle treatment, the wear rate decreased by 36.4 pct, which is about 3.3 times lower than that of 316L SS. Meanwhile, cryogenic thermal cycling is beneficial to reduce the coefficient of friction (COF). The dominant wear mechanism is the abrasive wear combined with corrosive wear. The improved toughness and passivation ability due to the cryogenic thermal cycling are responsible for the decline of Delta V-W, so as to enhance the tribocorrosion resistance. Therefore, cryogenic thermal cycling could be an effective way to improve the tribocorrosion performance of amorphous alloys and coatings in marine environment.

Automated summary

The effects of cryogenic thermal cycling on the tribocorrosion behavior of Fe41Co7Cr15Mo14C15B6Y2 bulk amorphous alloy in 3.5 pct NaCl solution were studied. The results showed that the cryogenic thermal cycling treatment increased the relaxation enthalpy and fracture toughness, while decreasing the hardness. Additionally, the corrosion resistance was improved due to the formation of a more stable passive film. The corrosive wear rates of the alloy decreased with the increase of the number of cryogenic thermal cycles, and the wear rate after 60-cycle treatment was significantly lower compared to 316L SS. Cryogenic thermal cycling also reduced the coefficient of friction, and the dominant wear mechanism was abrasive wear combined with corrosive wear. The improved toughness and passivation ability resulting from cryogenic thermal cycling were responsible for the enhanced tribocorrosion resistance. Therefore, cryogenic thermal cycling could be an effective method to improve the tribocorrosion performance of amorphous alloys and coatings in marine environment.