A new thermodynamic parameter to predict glass forming ability in iron based multi-component systems containing zirconium

► A new and improved GFA parameter is proposed for multi-component Fe based systems. ► GFR calculated in Fe-Zr-B system is in good agreement with experiments. ► Experiments on Fe-Cr-Ni-Zr-B alloys indicate that PHSS is a better GFA parameter. ► A PHSS of −3 kJ/mol delineates ordinary glass forming composition from BMGs. ► The maximum thickness of a BMG is found to increase with decreasing PHSS.