Effects of Ca addition on the glass formation, microhardness and corrosion resistance in different solutions of Zr66.7−xNi33.3Cax (x = 0, 1, 3 and 5 at.%) metallic glasses

In this study, the effects of the Ca addition on the glass forming ability (GFA), thermal stability, microhardness and corrosion resistance of as-spun Zr66.7−xNi33.3Cax (x = 0, 1, 3 and 5 at.%) alloys have been investigated using X-ray diffraction (XRD), differential scanning calorimetry (DSC), Vickers-type hardness tester and electrochemical measurement. The corroded sample surfaces were examined using field emission scanning electron microscopy (FESEM). The results show that the Ca addition can effectively enhance the GFA of the as-spun Zr-based alloys. Moreover, the Zr63.7Ni33.3Ca3 metallic glass shows the highest thermal stability indicated by the largest activation energy for crystallization. The Ca addition can effectively enhance the microhardness and 3 at.% Ca addition exhibits the highest microhardness value. The corrosion resistance of the Zr-based metallic glasses in 0.5 M NaCl, 1 M HCl and 1 M NaOH solutions has been tested by electrochemical workstation. 5 at.% Ca addition effectively improve the corrosion resistance of Zr-based metallic glasses in chloride-containing solutions, and all the Zr-based metallic glasses exhibit good corrosion resistance in NaOH solution.