Corrosion Performance in 0.5 mol/L HF Solution of Cr-Cu-Mo-Ni Porous Alloys with Varying Cr Contents

An activation reaction sintering process was utilized to produce Cr-Cu-Mo-Ni porous alloys. Subsequently, weight loss measurements and electrochemical methods were applied to investigate the effect of Cr content ranging from 10wt% to 30wt% on the corrosive properties of Cr-Cu-Mo-Ni alloys in a 0.5 mol/L HF solution. Scanning electron microscopy (SEM) and X-ray diffraction analyses (XRD) were performed to assess the structural morphology and phase composition. As the results illustrated, Cr-Cu-Mo-Ni porous alloys possess good corrosion resistance, which is significantly higher than that of dense Ni and Cu alloys. The anti-corrosion performance of porous alloys is not proportional to the Cr content when the Cr concentration is gradually increased. When the chromium content is 20%, it exhibits the best corrosion resistance. Electrochemical measurements yielded similar results to weight loss measurements. With an increasing Cr content, double capacitive loops in electrochemical impedance spectroscopy (EIS) tests for Cr-Cu-Mo-Ni porous alloys first increased and then decreased, indicating that the corrosion process can be regulated by an electrochemical reaction. Meanwhile, after analysis, the results show that the corrosion products on the material surface adhere to the inner surface of the pores, thus improving the corrosion resistance.