Study On Glass Forming Ability And Properties Of FeCoNi Base Bulk Amorphous Alloys

Fe-based bulk amorphous alloys (BMG) have been gaining wide attendtion. Howerver, Fe-based BMG without any metalloid elements have never been explored, which may have many potential applications. rods with a diameter of 2mm and 3mm were obtained by copper-mold vacuum suction casting. Rapidly solidified alloy ribbons were produced by melt-spinning. The microstructure, thermal stability and magnetic was examined by X-ray diffraction, differential scanning calorimetry and vibrating sample magnetometer, respectively. The results showed that:From the view point of cluster base composition rule, (Fe,Co,Ni)-base alloys were designed.In (FeCoNi)-Zr-Mo alloy systems, (Fe0.54Co0.42Ni0.04)75.6Zr12.4Mo12 have higher glass forming ability(GFA) than (Fe0.54Co0.42Ni0.04)73.7Zr8.3Mo18. (Fe0.54Co0.42Ni0.04)72Zr17Mo11 show little crystalline bragg peaks and small exothermic peak. Introducting microalloy element into the (FeCoNi)-Zr-Mo alloy system increase its GFA. [(Fe0.54Co0.42Ni0.04)75.4Zr12.4Mo12]94Nb6 and[(Fe0.54Co0.42Ni0.04)75.4Zr12.4Mo12]98W2 show better GFA than the samples with microalloy element Si and P.From the view point of eutectic point, heat of mixing, atomic size difference and microalloying, Ni-Zr-Ti-Nb with high glass forming ability were designed. (Ni61.9Zr15.1Ti12Nb10.7)96Sn4 bulk metallic glassy rods with a diameter of 2mm were obtained by copper-mold vacuum suction casting.The effect of the fourth element on thermal stability and glass-forming ability (GFA) in Ni-Nb-Ti-X (X= Co, Hf) bulk metallic glass (BMG) system has been studied.2mm (Ni60Nb25Ti15)96Hf4 bulk metallic glasses (BMGs) were realized. Exhibits high Tg of 829K, supercooled liquid region of 49K. The addition of Co increases the supercooled liquid region of Ni-Nb-Ti alloy systems to about 100K. Besides, the DSC curves of partial glassy rods and glassy ribbon of Ni45Nb25Ti15Co15 are compared. The three-stage exothermic peak behavior are observed in the ribbon sample of Ni45Nb25Ti15Co15. However, only a peak with Tx as high as about 1029K can be observed for the 2mm rod with partial glassy phase.