Synthesis of Cr50Fe6Co7Mo14C15B6Y2 bulk metallic glass with integrated merits by high-content solvent element substitution and the structural origin

Novel Cr50Fe6Co7Mo14C15B6Y2 bulk metallic glass (BMG) with a critical diameter of about 1.5 mm was developed using high-content solvent element Cr substitution for Fe from the precursor Fe41Cr15Co7Mo14C15B6Y2 BMG. The alloy possesses integrated advantages of superior glass transition temperature of 981 K, extraordinary high onset temperature of crystallization of 1018 K, dramatical high compressive fracture strength of 4.49 GPa and Vickers microhardness of 14.01 GPa, and prominent corrosion resistance of no detectable weight loss in 1 M HCl solution. The structural origin for the decreased glass-forming ability of the present alloy in comparison with its precursor Fe41Cr15Co7Mo14C15B6Y2 BMG results from the lower fraction of icosahedral-type structures (with bond pair indexes of 1551, 1541, and 1431) along with the higher fraction of crystal-like structures (with bond pair indexes of 1421, 1422, 1441 and 1661), and the covalent-like Cr–C and Cr–B bonds are responsible for the superior glass transition temperature, the onset temperature of crystallization, fracture strength and hardness, based on the ab-initio molecular dynamics simulation for the local structures. The present BMG can be a preferable alloy for industrial applications under the harsh environment of high temperature, wear and corrosion.