Preparation of Ni-based bulk metallic glasses with high corrosion resistance

Abstract

Bulk Ni77−x−yMoxCryNb3P14B6 (x=7 y=0; x=8 y=0; x=9 y=0; x=5 y=3; x=5 y=5; x=5 y=8; x=8 y=3; x=8 y=5, all in at.%) glassy alloy rods with the diameters of 1.0–1.5mm were synthesized by combining fluxing technique and J-quenching technique. The effects of Mo and Cr substitution for Ni on the glass forming ability (GFA), thermal stability, mechanical properties and corrosion properties of the present Ni-based bulk metallic glasses (BMGs) had been studied systematically. It is found that the substitution of an appropriate amount of Cr and Mo for Ni can enhance the GFA of the present Ni-based alloys, while excessive substitution will lead to the degradation of the GFA. The corrosion tests show that the corrosion current density and corrosion rate of most of the present Ni-based BMGs in 1M NaCl and 1M HCl solutions are in the order of 10−6A/cm2 and 10−2mm/year, respectively, exhibiting very high corrosion resistance. The addition of the appropriate Mo content and the Cr content as much as possible are benefit for the enhancement of the corrosion resistance of the present Ni-based BMGs. The compressive tests show that that the present Ni-based BMGs exhibit a compressive strength of 2.5–3.4GPa, but nearly zero compressive plasticity.