Microstructure and properties of ultra-thick Fe-based metallic glass by twin-roll strip casting versus a traditional process

摘要

In this study, an ingenious twin-roll strip casting approach is described to process large-size Fe71Ni9P12B4.9Si2.5Cu0.6 amorphous ribbons. The 150 mu m thick RT ribbon (novel process) characterized by a completely amorphous structure is 5 to 7 times thicker than the conventional Fe-based RS (conventional process) ribbon. The minimum cooling rates of the RS and RT ribbon were 1.78 x 106 and 5.58 x 105 K/s. The RT ribbon's excellent thermodynamic properties led to fine grain size and a high magnetic induction of 1.63 T. However, high internal stress led to a large magnetocrystalline anisotropy. The hardness of the two ribbons was similar at -1160 Hv. Moreover, the significant size effect led to a slight decrease in the fracture toughness of the RT ribbon. The impressive specifications, high impurity tolerance, and good properties of the RT ribbon render twin-roll strip casting promising for industrial applications.