Prominent Fe-based bulk amorphous steel alloy with large supercooled liquid region and superior corrosion resistance

摘要

A prominent Fe-base bulk amorphous steel (BAS) alloy which presents high glass forming ability (GFA), good corrosion resistance, superior mechanical properties and relative lower cost. The Fe_(41)Cr_(15)Co_7Mo_(14)-C_(21-x)B_xY_2 (x = 5-10) BAS rods with a diameter of 2-6 mm, can be fabricated by the suction casting method. The highest GFA value can be obtained by adjusting the ratio of boron/carbon, reaching to the value of γ = 0.4 and γ_m = 0.69 for the alloy composition of Fe_(41)Ce_(15)Co_7Mo_(14)C_(12)B_9Y_2. Meanwhile, this alloy also presents very large supercooled liquid region up to 81 K, favourable to be fabricated into microsurgery tools by thermoplastic forming. In addition, the Fe-base BAS alloy exhibits extremely high hardness around 1200 Hv. The anodic polarization measurement of the Fe-based BAS exhibits a higher corrosion resistance than 304 SS and 316 SS in the Hank's balanced salt solution. The sharpness test results reveal that the Fe-based BAS blade exhibits much higher sharpness because of its lower surface roughness and higher hardness. Moreover, the Fe-base BAS blade presents much better durability on cutting testing, it can remain relatively sharper edge-tip with a low blade sharpness index (BSI) value of 0.38 (in comparison with the BSI value of 0.59 for commercial blades) after the cutting testing over 50 cm length.