The structure and morphology of as-cast Fe-13wt-% Mo-0.8wt-% C alloy have been ob- served under SEM and TEM.Few δ-eutectoid but certain minor eutectics appear in the core of dendrites of the alloy.The eutectic carbid...The structure and morphology of as-cast Fe-13wt-% Mo-0.8wt-% C alloy have been ob- served under SEM and TEM.Few δ-eutectoid but certain minor eutectics appear in the core of dendrites of the alloy.The eutectic carbide is found as skeleton M_6C while the eutectoid carbide as rodlet M_6C.展开更多
研究了合金成分、烧结气氛对Fe Mo Mn Sn Ce C系合金的力学性能与烧结温度的影响以及在烧结合金中的作用机理。结果表明 :适量的Mn、Sn、混合稀土和氨燃烧氮基保护气氛均可加速该系合金的烧结进程 ,降低其烧结温度 ,改善其力学性能 ,而...研究了合金成分、烧结气氛对Fe Mo Mn Sn Ce C系合金的力学性能与烧结温度的影响以及在烧结合金中的作用机理。结果表明 :适量的Mn、Sn、混合稀土和氨燃烧氮基保护气氛均可加速该系合金的烧结进程 ,降低其烧结温度 ,改善其力学性能 ,而且具有协同、叠加强化效果。其强化作用主要体现在稀土元素的脱氧保碳、变质夹杂物、细化晶粒 ,Mn、Sn元素的固溶强化以及氨燃烧氮基保护气氛对烧结热效率、合金表层脱碳状况、烧结活化能的改善等方面。该系合金在氨燃烧氮基保护气氛中的合适烧结温度范围为 10 2 5～ 10 75℃ ,比Fe Mo Ni C系合金的烧结温度降低了 12 0～ 180℃。展开更多
Thermal stability,crystallization behavior,Vickers hardness and magnetic properties of the Fe41Co7-xNixCr15Mo14C15B6Y2（x=0,1,3,5） bulk metallic glasses were investigated.The Fe41Co7-xNixCr15Mo14C15B6Y2（x=0,1,3,5） ...Thermal stability,crystallization behavior,Vickers hardness and magnetic properties of the Fe41Co7-xNixCr15Mo14C15B6Y2（x=0,1,3,5） bulk metallic glasses were investigated.The Fe41Co7-xNixCr15Mo14C15B6Y2（x=0,1,3,5） metallic glasses were fabricated by copper mold casting method.The thermal stability and crystallization behavior of the metallic glass rods were investigated by differential scanning calorimetry and isothermal experiments.Hardness measurements for samples annealed at different temperatures for different time were carried out at room temperature by the Vickers hardness tester,and magnetic measurements were performed at different temperatures by the vibrating sample magnetometer.It is shown that the addition of Ni does not play a positive role for enlarging ΔTx and GFA from parameter γ（=Tx/（Tg＋Tl））,and it can,however,increase the activation energy in the initial stage of crystallization by changing the initial crystallization behavior.The minor addition of Ni can refine the crystal grain obtained from the full crystallization experiment.The primary crystallization causes the decrease of hardness in these alloys,and as the crystallization continues,the hardness in all samples increases instead due to the precipitation of carbide and boride.The annealing temperature has an obvious effect on magnetic properties of these alloys,and the minor addition of Ni can effectively prevent the alloy annealed at high temperature to transform from paramagnetic to ferromagnetic state.展开更多
文摘The structure and morphology of as-cast Fe-13wt-% Mo-0.8wt-% C alloy have been ob- served under SEM and TEM.Few δ-eutectoid but certain minor eutectics appear in the core of dendrites of the alloy.The eutectic carbide is found as skeleton M_6C while the eutectoid carbide as rodlet M_6C.
文摘研究了合金成分、烧结气氛对Fe Mo Mn Sn Ce C系合金的力学性能与烧结温度的影响以及在烧结合金中的作用机理。结果表明 :适量的Mn、Sn、混合稀土和氨燃烧氮基保护气氛均可加速该系合金的烧结进程 ,降低其烧结温度 ,改善其力学性能 ,而且具有协同、叠加强化效果。其强化作用主要体现在稀土元素的脱氧保碳、变质夹杂物、细化晶粒 ,Mn、Sn元素的固溶强化以及氨燃烧氮基保护气氛对烧结热效率、合金表层脱碳状况、烧结活化能的改善等方面。该系合金在氨燃烧氮基保护气氛中的合适烧结温度范围为 10 2 5～ 10 75℃ ,比Fe Mo Ni C系合金的烧结温度降低了 12 0～ 180℃。
文摘以乙醇作为碳源,Mo-Fe/C为催化剂,采用化学气相沉积法(CVD)制备碳纳米管(CNTs)/C复合材料,利用SEM和TEM对其形貌和结构进行表征。同时对于CNTs/C复合材进行电化学性能测试,碳纳米管的内径3~6 nm,外径20~22 nm。结果表明:CNTs/C作为锂离子电池的负极材料具有较高的电池容量,经过10次循环,电池比容量保持在385 m A·h·g-1。
基金Project(2012CB825700) supported by the National Basic Research Program of China
文摘Thermal stability,crystallization behavior,Vickers hardness and magnetic properties of the Fe41Co7-xNixCr15Mo14C15B6Y2（x=0,1,3,5） bulk metallic glasses were investigated.The Fe41Co7-xNixCr15Mo14C15B6Y2（x=0,1,3,5） metallic glasses were fabricated by copper mold casting method.The thermal stability and crystallization behavior of the metallic glass rods were investigated by differential scanning calorimetry and isothermal experiments.Hardness measurements for samples annealed at different temperatures for different time were carried out at room temperature by the Vickers hardness tester,and magnetic measurements were performed at different temperatures by the vibrating sample magnetometer.It is shown that the addition of Ni does not play a positive role for enlarging ΔTx and GFA from parameter γ（=Tx/（Tg＋Tl））,and it can,however,increase the activation energy in the initial stage of crystallization by changing the initial crystallization behavior.The minor addition of Ni can refine the crystal grain obtained from the full crystallization experiment.The primary crystallization causes the decrease of hardness in these alloys,and as the crystallization continues,the hardness in all samples increases instead due to the precipitation of carbide and boride.The annealing temperature has an obvious effect on magnetic properties of these alloys,and the minor addition of Ni can effectively prevent the alloy annealed at high temperature to transform from paramagnetic to ferromagnetic state.
