The Glass Forming Ability and Magnetic Properties of Fe–Nb–B–Ta Metallic Glasses

• Main Authors: Yu-Lin Wang, 王毓麟
• Other Authors: 陳適範
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/sy93j4

碩士 === 國立臺北科技大學 === 材料科學與工程研究所 === 98 === The effects of Ta addition on glass forming ability and soft magnetic properties of Fe-Nb-B metallic glass were investigated. The (Fe72Nb4B24)100-xTax (x = 0,1,2,3,4,5 and 6 at.%) ingots were arc-melted under argon atmosphere. A single roller melt-spinning method was employed to produce the alloy ribbons, and the copper mold injection casting was used to prepare 2mm alloy rods. The microstructures of alloy ribbons were shown to be amorphous when Ta additions ranged 0 and 4 at.%. Their ΔTx (= Tx-Tg) increased from 54.5 K (x = 0 at.%) to 70.7 K (x = 3 at.%) and subsequently decreased to 55.9 K (x = 5 at.%). Therefore, the values of ΔTx (= Tx-Tg), Trg (= Tg/Tm or Tg/Tl), γ, Rc, Zc, and Dmax was optimal with 3 at.% of Ta addition. The large ΔTx indicated that the Fe-Nb-B-Ta metallic glass had high glass forming ability and good thermal stability. The saturation magnetization (Ms) of Fe-Nb-B-Ta alloy ribbons decreased from 1.14 T to 0.64 T with increasing Ta from 0 at.% to 6 at.%, and the coercive force (Hc) decreased from 62.5 A/m to 13.2 A/m (x = 1 at.%) and then increased to 65.6 A/m (x=6 at.%). For alloy rods, the Ms decreased from 1.3 T to 0.9 T. Hc decreased from 3118 A/m to 2677 A/m (x = 1 at.%) and then increased to 5962 A/m (x = 6 at.%). Among the alloys investigated, (Fe72Nb4B24)99Ta1 demonstrated a combination of good glass forming ability and optimal soft magnetic properties in either ribbon or rod forms.