Three new Fe-based microcrystalline alloys,i.e.,Fe_(73.1)Cu_(1.2)Nb_(3.2)Si_(12 5)B_(10), Fe_(73)Cu_1Nb_(1.5)Mo_2Si_(12.5)B_(10) and Fe_(73)Cu_1Zr_3C_(0.5)Mo_Si_(12.5)B_(10),were developed with su- perior magnetic pro...Three new Fe-based microcrystalline alloys,i.e.,Fe_(73.1)Cu_(1.2)Nb_(3.2)Si_(12 5)B_(10), Fe_(73)Cu_1Nb_(1.5)Mo_2Si_(12.5)B_(10) and Fe_(73)Cu_1Zr_3C_(0.5)Mo_Si_(12.5)B_(10),were developed with su- perior magnetic properties.e.g.,high relative initial permeability of μ_i^15×10~4,low coercivity of H_c1.0A/m,high effective permeability and low core losses in a consid- crable wide frequency range and high pulse-magnetic permeability under narrow pulse. The optimum value of relative effective permeability,μ_5~1 is 16×10~4 under condition of f=1 kHz and H_m=0.4 A/m.The optimum values of core loss reach 57.9 30.2 and 68 W/kg under condition of f=50.100.100 KHz and B_m=0.5,0.2,0.3 T,respectively. These three alloys have superior stability of magnetic properties.Initial permeability may be not changed during heating at 130℃ up to 216 h.The main crystalline phase is ordered phase Fe_((75)+y)Si_((25)-y) which is ultrafine particles of average size 10—20 nm.展开更多
Microstructure, thermodynamics and electrochemicalproperties of novel RE (NiAlCu)x(x= 4.5, 4.9, 5.6 ) microcrystalline hydrogen-storage alloy powder prepared by gas atomization wasinvestigated. It indicates that alloy...Microstructure, thermodynamics and electrochemicalproperties of novel RE (NiAlCu)x(x= 4.5, 4.9, 5.6 ) microcrystalline hydrogen-storage alloy powder prepared by gas atomization wasinvestigated. It indicates that alloyparticles show relatively regularspherical. Microstructure is composed of the AB5 matrix phase andeutectic double-phase structure withthe AB5 phase and Ni3Al along grainboundaries when x = 5. 6, there is acoexistent structure consisting ofAB5 phase and eutectic doublephase with AB3 and AB phases along grain boundaries at x= 4.5.When x is increased to 4.9, themixed structures are composed ofAB5 and a few AB phases in discontinuous network distribution. Theelectrochemical capacity of alloy is210~300 mAh·g-1, and the activated periods are only 1~3 times.lt seems to be ascribed to the appearance of a great number of freshsurfaces within powder particles resulting from the as-quenched microcrack along the interphase boundaries within particles propagatinggradually in the process of hydrogen-absorption-and dissociation dueto the intrinsic double-phase structure.展开更多
A simple but more efficient technique—high-frequency electropulse deposition—was developed to produce microcrystallized MGH754 ODS alloy coatings on the 1Cr18Ni9Ti stainless steel substrate. The coating has a very f...A simple but more efficient technique—high-frequency electropulse deposition—was developed to produce microcrystallized MGH754 ODS alloy coatings on the 1Cr18Ni9Ti stainless steel substrate. The coating has a very fine grain size of 30–300 nm and metallurgical bonding with the substrate. Isothermal oxidation in air at 1 000°C for 100 h shows that micro-crystallisation and dispersed oxide particles promote the selective oxidation of Cr greatly to form a protective and continuous Cr2O3 scale and also improve the scale spallation resistance dramatically, thus increasing the oxidation resistance of 1Cr18Ni9Ti.展开更多
文摘Three new Fe-based microcrystalline alloys,i.e.,Fe_(73.1)Cu_(1.2)Nb_(3.2)Si_(12 5)B_(10), Fe_(73)Cu_1Nb_(1.5)Mo_2Si_(12.5)B_(10) and Fe_(73)Cu_1Zr_3C_(0.5)Mo_Si_(12.5)B_(10),were developed with su- perior magnetic properties.e.g.,high relative initial permeability of μ_i^15×10~4,low coercivity of H_c1.0A/m,high effective permeability and low core losses in a consid- crable wide frequency range and high pulse-magnetic permeability under narrow pulse. The optimum value of relative effective permeability,μ_5~1 is 16×10~4 under condition of f=1 kHz and H_m=0.4 A/m.The optimum values of core loss reach 57.9 30.2 and 68 W/kg under condition of f=50.100.100 KHz and B_m=0.5,0.2,0.3 T,respectively. These three alloys have superior stability of magnetic properties.Initial permeability may be not changed during heating at 130℃ up to 216 h.The main crystalline phase is ordered phase Fe_((75)+y)Si_((25)-y) which is ultrafine particles of average size 10—20 nm.
文摘Microstructure, thermodynamics and electrochemicalproperties of novel RE (NiAlCu)x(x= 4.5, 4.9, 5.6 ) microcrystalline hydrogen-storage alloy powder prepared by gas atomization wasinvestigated. It indicates that alloyparticles show relatively regularspherical. Microstructure is composed of the AB5 matrix phase andeutectic double-phase structure withthe AB5 phase and Ni3Al along grainboundaries when x = 5. 6, there is acoexistent structure consisting ofAB5 phase and eutectic doublephase with AB3 and AB phases along grain boundaries at x= 4.5.When x is increased to 4.9, themixed structures are composed ofAB5 and a few AB phases in discontinuous network distribution. Theelectrochemical capacity of alloy is210~300 mAh·g-1, and the activated periods are only 1~3 times.lt seems to be ascribed to the appearance of a great number of freshsurfaces within powder particles resulting from the as-quenched microcrack along the interphase boundaries within particles propagatinggradually in the process of hydrogen-absorption-and dissociation dueto the intrinsic double-phase structure.
文摘A simple but more efficient technique—high-frequency electropulse deposition—was developed to produce microcrystallized MGH754 ODS alloy coatings on the 1Cr18Ni9Ti stainless steel substrate. The coating has a very fine grain size of 30–300 nm and metallurgical bonding with the substrate. Isothermal oxidation in air at 1 000°C for 100 h shows that micro-crystallisation and dispersed oxide particles promote the selective oxidation of Cr greatly to form a protective and continuous Cr2O3 scale and also improve the scale spallation resistance dramatically, thus increasing the oxidation resistance of 1Cr18Ni9Ti.
