High strength CoFe-based glassy alloy with high thermal stability

摘要

With the aim of synthesizing a new ferromagnetic CoFe-based glassy alloy with a large supercooled liquid region, we studied the (Co_xFe_(1-x))_(62)Nb_8B_(30) (x=0-1) alloy system. The alloy corresponding to x=0.5 exhibits a large supercooled liquid region of 101 K, together with a high fracture strength of approximately 5000 MPa at room temperature and superplasticity near its glass transition temperature. In addition, the x=0.5 alloy as a soft magnetic material shows a low coercivity below 2 A/m, a high effective permeability of about 20,000 at 1 kHz and 3400 at 1 MHz as well as a giant magnetoimpedance ratio of 62%. The combination of superplasticity and soft magnetic properties makes this alloy promising for future functional applications.