Papers by Author: Bao Long Shen

Abstract: Fe- and Co-based bulk glassy alloys (BGAs) with diameters up to 5 and 4 mm were formed respectively in (Fe,Co)-B-Si-Nb system by copper mold casting. The Fe-based glassy alloys in [(Fe1-xCox)0.75B0.2Si0.05]96Nb4 system exhibit saturation magnetization (Is) of 0.84-1.13 T and low coercive force (Hc) of 1.5-2.7 A/m. Its BGAs exhibit superhigh strength ( σ f) of 3900-4250 MPa, Young’s modulus (E) of 190-210 GPa, elastic strain (εe) of 0.02 and plastic strain (εp) of 0.0025. For the Co-based glassy alloys in [(Co1-xFex)0.75B0.2Si0.05]96Nb4 system, in addition to superhigh σ f of 3980-4170 MPa, they also exhibit excellent soft magnetic properties, i.e., Is of 0.71-0.97 T, Hc of 0.7-1.8 A/m, high effective permeability (μe) of 1.48-3.25×104 at 1 kHz under a field of 1 A/m, and extremely low saturation magnetostriction (λs) of 0.55-5.76×10-6.

Abstract: This paper reviews our recent results of the formation, fundamental properties, workability and applications of late transition metal (LTM) base bulk glassy alloys (BGAs) developed since 1995. The BGAs were obtained in Fe-(Al,Ga)-(P,C,B,Si), Fe-(Cr,Mo)-(C,B), Fe-(Zr,Hf,Nb,Ta)-B, Fe-Ln-B(Ln=lanthanide metal), Fe-B-Si-Nb and Fe-Nd-Al for Fe-based alloys, Co-(Ta,Mo)-B and Co-B-Si-Nb for Co-based alloys, Ni-Nb-(Ti,Zr)-(Co,Ni) for Ni-based alloys, and Cu-Ti-(Zr,Hf), Cu-Al-(Zr,Hf), Cu-Ti-(Zr,Hf)-(Ni,Co) and Cu-Al-(Zr,Hf)-(Ag,Pd) for Cu-based alloys. These BGAs exhibit useful properties of high mechanical strength, large elastic elongation and high corrosion resistance. In addition, Fe- and Co-based glassy alloys have good soft magnetic properties which cannot be obtained for amorphous and crystalline type magnetic alloys. The Feand Ni-based BGAs have already been used in some application fields. These LTM base BGAs are promising as new metallic engineering materials.

Abstract: Glassy Fe77Ga3P9.5C4B4Si2.5 alloy powders were synthesized in the particle size range below 125 µm by Ar gas atomization. A glassy alloy disc of 10 mm in diameter and 3 mm in thickness with a high relative density of 99.7 % was synthesized by spark plasma sintering. The resulting glassy magnetic core exhibits good soft magnetic properties, i.e., 1.35 T for saturation magnetization, 5 A/m for coercive force and 9600 for maximum permeability.