The Experts below are selected from a list of 7145613 Experts worldwide ranked by ideXlab platform
Maria Neagu - One of the best experts on this subject based on the ideXlab platform.
-
Saturation magnetostriction of Co-rich glass-covered amorphous wires
Journal of Magnetism and Magnetic Materials, 2002Co-Authors: Maria Neagu, Manuel Vázquez, Horia Chiriac, F. Borza, T.-a. ÓváriAbstract:Abstract The influence of Fe addition on saturation magnetostriction at zero applied stress, λ s (0), for Co 72.5− x Fe x Si 12.5 B 15 ( x =0, 3, 4.35, 5, and 7 at%) glass-covered amorphous wires was investigated. Samples were tested in As-Cast State and after AC Joule-heating under applied stress. In As-Cast State the alloys with 0, 3 and 4.35 at% Fe have negative λ s (0) while the alloys with 5 and 7 at% Fe have positive λ s (0).
-
Saturation magnetostriction measurement in nearly zero magnetostrictive Co-rich glass-covered amorphous wires
Journal of Magnetism and Magnetic Materials, 2002Co-Authors: Horia Chiriac, Maria Neagu, M. Vazquez, E. HristoforouAbstract:The magnetostrictive behaviour of Co68.1Fe4.35Si12.5B15 glass-covered amorphous wires in the As-Cast State and stress-current annealed between 20-80 mA, under 200-500 MPa, is reported. For As-Cast as well as stress annealed samples the value of stress derivative a is about -0.9 x 10(-10) MPa-1. In the As-Cast State the value of saturation magnetostriction at zero applied stress lambda(s)(0) is about -1.11 x 10(-7). After stress-current annealing lambda(s)(0) decreases in absolute value, changing continuously from small negative to small positive values when the annealing time increases. The positive magnetostriction is obtained for annealing current density higher than about 130 x 10(6) A/m(2). (C) 2002 Elsevier Science B.V. All rights reserved
-
Saturation magnetostriction measurement in nearly zero magnetostrictive Co-rich glass-covered amorphous wires
Journal of Magnetism and Magnetic Materials, 2001Co-Authors: Horia Chiriac, Manuel Vázquez, Maria Neagu, Evangelos HristoforouAbstract:Abstract The magnetostrictive behaviour of Co 68.15 Fe 4.35 Si 12.5 B 15 glass-covered amorphous wires in the As-Cast State and stress-current annealed between 20–80 mA, under 200–500 MPa, is reported. For As-Cast as well as stress annealed samples the value of stress derivative α is about −0.9×10 −10 MPa −1 . In the As-Cast State the value of saturation magnetostriction at zero applied stress λ s (0) is about –1.11×10 −7 . After stress-current annealing λ s (0) decreases in absolute value, changing continuously from small negative to small positive values when the annealing time increases. The positive magnetostriction is obtained for annealing current density higher than about 130×10 6 A/m 2 .
-
Sound velocity in Fe-rich glass covered amorphous wires
Journal of Non-Crystalline Solids, 2001Co-Authors: Horia Chiriac, Maria Neagu, Evangelos Hristoforou, I. Darie, Anca Eugenia MogaAbstract:Abstract The bias magnetic field ( H ) dependence of the longitudinal sound velocity ( v ) in Fe 77.5 Si 7.5 B 15 glass covered amorphous wires is reported. The amorphous wires were tested in the As-Cast State and after dc current annealing between 5 and 20 mA for 10–30 min. For the glass covered amorphous wires tested in the As-Cast State the bias magnetic field dependence of the sound velocity was insignificant. For current annealed samples a decrease of the sound velocity for the smaller bias magnetic fields was observed. Increasing the annealing temperature, the bias magnetic field corresponding to the v minimum decreased. For about 600 A/m bias magnetic field, the longitudinal sound velocity reaches saturation.
-
Torsion and magnetic field measurements using inverse Wiedemann effect in glass-covered amorphous wires
Sensors and Actuators A: Physical, 2000Co-Authors: H Chiriac, Maria Neagu, I. Darie, E. Hristoforou, Cornelia HisonAbstract:This paper presents results concerning inverse Wiedemann effect (IWE) dependence on the torsion and d.c. magnetic field applied along the length of the Fe77.5Si7.5B15 glass-covered amorphous wires tested in the As-Cast State both before and after glass removal. In the absence of torsion during measurements, the IWE voltage is zero. Increasing the torsion value up to about 55 rad/m increase
Horia Chiriac - One of the best experts on this subject based on the ideXlab platform.
-
Saturation magnetostriction of Co-rich glass-covered amorphous wires
Journal of Magnetism and Magnetic Materials, 2002Co-Authors: Maria Neagu, Manuel Vázquez, Horia Chiriac, F. Borza, T.-a. ÓváriAbstract:Abstract The influence of Fe addition on saturation magnetostriction at zero applied stress, λ s (0), for Co 72.5− x Fe x Si 12.5 B 15 ( x =0, 3, 4.35, 5, and 7 at%) glass-covered amorphous wires was investigated. Samples were tested in As-Cast State and after AC Joule-heating under applied stress. In As-Cast State the alloys with 0, 3 and 4.35 at% Fe have negative λ s (0) while the alloys with 5 and 7 at% Fe have positive λ s (0).
-
Saturation magnetostriction measurement in nearly zero magnetostrictive Co-rich glass-covered amorphous wires
Journal of Magnetism and Magnetic Materials, 2002Co-Authors: Horia Chiriac, Maria Neagu, M. Vazquez, E. HristoforouAbstract:The magnetostrictive behaviour of Co68.1Fe4.35Si12.5B15 glass-covered amorphous wires in the As-Cast State and stress-current annealed between 20-80 mA, under 200-500 MPa, is reported. For As-Cast as well as stress annealed samples the value of stress derivative a is about -0.9 x 10(-10) MPa-1. In the As-Cast State the value of saturation magnetostriction at zero applied stress lambda(s)(0) is about -1.11 x 10(-7). After stress-current annealing lambda(s)(0) decreases in absolute value, changing continuously from small negative to small positive values when the annealing time increases. The positive magnetostriction is obtained for annealing current density higher than about 130 x 10(6) A/m(2). (C) 2002 Elsevier Science B.V. All rights reserved
-
Saturation magnetostriction measurement in nearly zero magnetostrictive Co-rich glass-covered amorphous wires
Journal of Magnetism and Magnetic Materials, 2001Co-Authors: Horia Chiriac, Manuel Vázquez, Maria Neagu, Evangelos HristoforouAbstract:Abstract The magnetostrictive behaviour of Co 68.15 Fe 4.35 Si 12.5 B 15 glass-covered amorphous wires in the As-Cast State and stress-current annealed between 20–80 mA, under 200–500 MPa, is reported. For As-Cast as well as stress annealed samples the value of stress derivative α is about −0.9×10 −10 MPa −1 . In the As-Cast State the value of saturation magnetostriction at zero applied stress λ s (0) is about –1.11×10 −7 . After stress-current annealing λ s (0) decreases in absolute value, changing continuously from small negative to small positive values when the annealing time increases. The positive magnetostriction is obtained for annealing current density higher than about 130×10 6 A/m 2 .
-
Sound velocity in Fe-rich glass covered amorphous wires
Journal of Non-Crystalline Solids, 2001Co-Authors: Horia Chiriac, Maria Neagu, Evangelos Hristoforou, I. Darie, Anca Eugenia MogaAbstract:Abstract The bias magnetic field ( H ) dependence of the longitudinal sound velocity ( v ) in Fe 77.5 Si 7.5 B 15 glass covered amorphous wires is reported. The amorphous wires were tested in the As-Cast State and after dc current annealing between 5 and 20 mA for 10–30 min. For the glass covered amorphous wires tested in the As-Cast State the bias magnetic field dependence of the sound velocity was insignificant. For current annealed samples a decrease of the sound velocity for the smaller bias magnetic fields was observed. Increasing the annealing temperature, the bias magnetic field corresponding to the v minimum decreased. For about 600 A/m bias magnetic field, the longitudinal sound velocity reaches saturation.
E. Hristoforou - One of the best experts on this subject based on the ideXlab platform.
-
Saturation magnetostriction measurement in nearly zero magnetostrictive Co-rich glass-covered amorphous wires
Journal of Magnetism and Magnetic Materials, 2002Co-Authors: Horia Chiriac, Maria Neagu, M. Vazquez, E. HristoforouAbstract:The magnetostrictive behaviour of Co68.1Fe4.35Si12.5B15 glass-covered amorphous wires in the As-Cast State and stress-current annealed between 20-80 mA, under 200-500 MPa, is reported. For As-Cast as well as stress annealed samples the value of stress derivative a is about -0.9 x 10(-10) MPa-1. In the As-Cast State the value of saturation magnetostriction at zero applied stress lambda(s)(0) is about -1.11 x 10(-7). After stress-current annealing lambda(s)(0) decreases in absolute value, changing continuously from small negative to small positive values when the annealing time increases. The positive magnetostriction is obtained for annealing current density higher than about 130 x 10(6) A/m(2). (C) 2002 Elsevier Science B.V. All rights reserved
-
Torsion and magnetic field measurements using inverse Wiedemann effect in glass-covered amorphous wires
Sensors and Actuators A: Physical, 2000Co-Authors: H Chiriac, Maria Neagu, I. Darie, E. Hristoforou, Cornelia HisonAbstract:This paper presents results concerning inverse Wiedemann effect (IWE) dependence on the torsion and d.c. magnetic field applied along the length of the Fe77.5Si7.5B15 glass-covered amorphous wires tested in the As-Cast State both before and after glass removal. In the absence of torsion during measurements, the IWE voltage is zero. Increasing the torsion value up to about 55 rad/m increase
-
Tensile stress dependence of the sound velocity in Fe-rich amorphous wires
Sensors and Actuators A: Physical, 2000Co-Authors: H Chiriac, Maria Neagu, I. Darie, E. Hristoforou, Cornelia HisonAbstract:Experimental results concerning the dependence of the longitudinal sound velocity in Fe77.5Si7.5B15 amorphous wires on the tensile stress applied along the length of the wire are reported. We tested Fe77.5Si7.5B15 amorphous wires, 125 μm in diameter, in the As-Cast State and after stress–relief process. The measurements were made using the magnetostrictive delay line principle. The obtained results show a stron
Cornelia Hison - One of the best experts on this subject based on the ideXlab platform.
-
Torsion and magnetic field measurements using inverse Wiedemann effect in glass-covered amorphous wires
Sensors and Actuators A: Physical, 2000Co-Authors: H Chiriac, Maria Neagu, I. Darie, E. Hristoforou, Cornelia HisonAbstract:This paper presents results concerning inverse Wiedemann effect (IWE) dependence on the torsion and d.c. magnetic field applied along the length of the Fe77.5Si7.5B15 glass-covered amorphous wires tested in the As-Cast State both before and after glass removal. In the absence of torsion during measurements, the IWE voltage is zero. Increasing the torsion value up to about 55 rad/m increase
-
Tensile stress dependence of the sound velocity in Fe-rich amorphous wires
Sensors and Actuators A: Physical, 2000Co-Authors: H Chiriac, Maria Neagu, I. Darie, E. Hristoforou, Cornelia HisonAbstract:Experimental results concerning the dependence of the longitudinal sound velocity in Fe77.5Si7.5B15 amorphous wires on the tensile stress applied along the length of the wire are reported. We tested Fe77.5Si7.5B15 amorphous wires, 125 μm in diameter, in the As-Cast State and after stress–relief process. The measurements were made using the magnetostrictive delay line principle. The obtained results show a stron
J. D. Gates - One of the best experts on this subject based on the ideXlab platform.
-
The effect of the reduction of carbon content on the toughness of high chromium white irons in the As-Cast State
Journal of Materials Science, 2004Co-Authors: A. Kootsookos, J. D. GatesAbstract:Three high chromium white cast irons were examined in the As-Cast State to determine the effect of the carbon content on the fracture toughness. The plane strain fracture toughness KIc and the fracture strength were measured for each alloy. X-ray mapping was used to identify the phases on the fracture surfaces. Scanning electron fractography and optical microscopy were used to determine the volume fraction of each phase on the fracture surfaces. It was found that most fracture occurred in the eutectic carbides, but that for the alloys with a reduced volume fraction of eutectic carbides, a small amount of crack propagation occurred in the austenitic dendrites. This change in crack path correlated with an increase in fracture toughness. The Ritchie-Knott-Rice model of brittle fracture was applied. It was found to sensibly predict the critical length for fracture for each alloy. Deep etching was employed to examine the distribution of eutectic carbides. It was found that the eutectic carbides formed a continuous network in each case.
-
The effect of heat treatment on the toughness, hardness and microstructure of low carbon white cast irons
Journal of Materials Science, 2001Co-Authors: M.-x. Zhang, P. M. Kelly, J. D. GatesAbstract:The effect of destabilisation and subcritical heat treatment on the impact toughness, hardness, and the amount and mechanical stability of retained austenite in a low carbon white cast iron have been investigated. The experimental results show that the impact energy constantly increases when the destabilisation temperature is raised from 950°C to 1200°C. Although the hardness decreases, the heat-treated hardness is still greater than the As-Cast State. After destabilisation treatment at 1130°C, tempering at 200 to 250°C for 3 hours leads to the highest impact toughness, and secondary hardening was observed when tempering over 400°C. The amount of retained austenite increased with the increase in the destabilisation temperature, and the treatment significantly improves the mechanical stability of the retained austenite compared with the As-Cast State. Tempering below 400°C does not affect the amount of retained austenite and its mechanical stability. But the amount of retained austenite is dramatically reduced when tempered above 400°C. The relationship between the mechanical properties and the microstructure changes was discussed.
