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Large Barkhausen discontinuities in Co-based amorphous wires with negative magnetostriction
38844
Jiles, D. C.
The effect of compressive plastic deformation on the magnetic properties of ALSI 4130 steels with various microstructures J o u r n a l of Physics D : A p p l i e d Physics, Vol. 21, No. 7, pp. 1196-1204 (14 Jul. 1988) The magnetic properties of AISI 4130 steel after eight heat treatments have been investigated. Properties such as hysteresis loss, coercivity, and initial permeability were found to be closely interrelated. Furthermore, they were each dependent on the hardness of the material. A relationship between the hardness and permeability was found which was microstructure independent. These parameters were also found to change in a systematic way with plastic deformation and this result can be used for non-destructive evaluation. Correlations between the magnetic parameters revealed relationships which depended on the mierostrueture of the material. The residual stress in steels can be determined from the changes in maximum differential permeability. 38843
Karjalainen, L.P.; Rautioaho, R.H.
Detection of fabrication stresses by the Barkhausen noise method T h e Effects of F a b r i c a t i o n R e l a t e d Stresses on P r o d u c t M a n u f a c t u r e a n d P e r f o r m a n c e , C a m b r i d g e ( U n i t e d K i n g d o m ) , 23-25 Sep. 1985. pp. 149-161. E d i t e d by J.F. A l d e r . T h e W e l d i n g I n s t i t u t e (1987) The high efficiency of the magnetic Barkhausen noise method for qualitative detection of stress changes due to welding, thermal and mechanical stress relief, machining and shot peening in structural steels is demonstrated. The importance of properly adjusting the strength of magnetization is pointed out. The steel composition, metallurgical structure, texture, dislocations and biaxiality of the stress field all affect the inherent Barkhausen noise level and its stress dependence, so that calibration for accurate determination of stress magnitudes does not generally seem reasonable. Examples of the practical applications of the method are briefly outlined. 38842
Jiles, D. C.
Magnetic properties and microstructure of AISI 1000 series carbon steels J o u r n a l of Physics D: A p p l i e d Physics, Vol. 21, No. 7, pp. 1186-1195 (14 Jul. 1988) The magnetic properties of a number of specimens of AISI 1000 series plain carbon steels have been measured as functions of chemical composition, microstructure and heat treatment. The results showed that for a given morphology of the carbides the magnetic properties such as eoercivity and permeability varied smoothly as a function of carbon content. Coercivity increased with carbon content by 2 . 0 0 e for every 0.1 wt% carbon added at low carbon contents while initial permeability decreased by 57% on the addition of 0.2 wt% carbon in the form of lamellar carbides (pearlitc), but by only 21% when those carbides were in the form of spheroidised particles. In all cases the spheroidised specimens were found to be magnetically softer than the lamellar specimens and the difference increased with the amount of carbon present. Grain size did not seem to affect the magnetic properties significantly above a carbon content of 0.2 wt%, although it was known that grain size is a significant factor in determining magnetic properties in iron alloys with lower carbon content. 38841
Ackerman, J.L.; Garrido, L.; Ellingson, W.A.; Weyand,
J.D. The use of NMR imaging to measure porosity and binder distributions in green-state and partially sintered ceramics M a s s a c h u s e t t s G e n e r a l H o s p i t a l , B o s t o n ( U n i t e d States), C O N F 870856-3, D E 8 8 - 0 0 3 0 9 9 , 34 pp. (Sop. 1987) Nonuniformities in porosity or binder distribution in green-state ceramic compacts can lead to failure in the final densified material. NMR imaging is a nondestructive characterization technique, most commonly used in medical diagnosis, which we have adapted for the production of tomographic images of porosity and of binder distributions. We measure open porosity by the imaging of a suitable filler fluid introduced into the part by vaccuum impregnation. Our results on partially sintered bodies show tough correlations with predicted porosity distributions. Results illustrating our techniques in a series el green-state and partially sintered aluminas.
Mikheev, M.N.; Kuleev, V.G.; Nesterenko, V.V.; Rigmant, M.B.; Mikhailovskaya, G.L; Nemkov, V.L.; Lobanova, L.V. 38840
New methods of nondestructive control of the mechanical properties of objects made of medium carbon steels S o v i e t J o u r n a l of N o n d e s t r u c t i v e T e s t i n g , Vol. 23, No. 7, pp. 445-449 ( M a r . 1988) The article suggests a method of nondestructive quality control for heat treated objects, made of medium carbon steels, which may be used in engineering for checking the mechanical properties of objects after hardening and tempering.
Krotov, L.N.; Shleenkov, A.S.; Rozenfel'd, E.V.: Shcherbinin, E.V.; Kop'ev, M.A. 38839
Analysis of ferroprobe operation with a controllable nonlinear electrical resistance in the exciting circuit S o v i e t J o u r n a l of N o n d e s t r u c t i v e T e s t i n g , Vol. 23, No. 7, pp. 455-462 ( M a r . 1988) The theoretical basis for a ferroprobe that has a controllable nonlinear electrical resistance (CNER) in an excitation circuit is discussed.
56
Tabachnik, V.P.; Chernova, G.S.; Fedorishcheva. E.E.; Turetskii, Ya. Sh.
38838
Magnetic inspection parameters of cermet plates containing cobalt Soviet J o u r n a l of N o n d e s t r u c t i v e Testing, Vol. 23, No~ 7, pp. 463-467 (Mar. 1988) Nondestructive inspection for the faces of cermet plates made from type T5K10 alloy is considered according to the normal component of the residual field that is produced by magnetizing an object with an electromagnet with a rod-type core. The relationship between the residual field and the magnetic characteristics of the materials is shown. 38837
Trusov, N.K.: Mel'gui, M.A.: Kulagin, V.N.; Shtdlovskaya.
E.A. Experimental method of determining shear plots in the neutral section of ferromagnetic cylinders made of structural steels Soviet J o u r n a l of N o n d e s t r u c t i v e Testing, Vol. 23, No. 7, pp. 472-477 (Mar. 1988) The article considers and substantiates, both theoretically and experimentally, a method of determining the central demagnetization factor ~! ferromagnetic cylinders made of structural steels and subjected to static magnetization along the anhysterefic magnetization curve 38836
Celasco, M.: Mazzetti, P.; Masoero, A.; Stepanescu, A.
Effects of the viscosity field on the Barkhausen noise of amorphous ferromagnetic materials J o u r n a l of A p p l i e d Physics, Vol. 63, No. ,~. pp. 2983-2985 ( t5 A p r 1988) Contrary to the case of crystalline or polyerystallinc materials, the magnetic aftereffect is almost always present in amorphous ferromagnetic materials. This fact makes the study of its influence very important in order to understand the magnetization dynamics of these materials, which have a growing technological interest. Experimental results prove the existence of a strong correlation between the magnetic aftereffect and the Barkhausen noise. In the present paper a theoretical study of the effect of the viscosity field on the power spectrum of the magnetization noise in amorphous materials will be given. Comparison with the available experimental results will also be made, showing a rather good agreement between theory and experiment 38835
Jiles, D.C.
Integrated on-line instrumentation for simultaneous automated measurement of magnetic field, induction, Barkhansen effect, magnetoacoustic emission, and magnetostriction J o u r n a l of A p p l i e d Physics, Vol. 63, No. 8. pp. 3946-3948 (15 Apr. 1988) A microcomputer-controlled inslrunlent for simultaneous measurement o[ magnetic hysteresis, magnetostricfion, Barkhausen effect, and magnetoacoustic emission is described. It incorporates custom designed software for control of the magnetic field during operations such as demagnetization, field sweeping, and anhysterctic magnetization, and for data logging and analysis. Results are recorded using a 12-bit analog to digital converter and are then stored on floppy disk. The magnetic hysteresis data are converted into six important magnetic parameters: coercivity, remanence, hysteresis loss, initial permeability, maximum differential permeability, and anhysterctic permeability. These, together with the magnetostriction, Barkhausen, and magnetoacoustic emission, are then related to the microstructure of the material.
Yarn~aki, .I.: Humphrey, F.B.: Mohri, K+; Kawamura, H.. Takamure, H.; Maelmhaell, R.
38834
Large Barkhausen discontinuities in Co-based amorphous wires with negative magnetostriction J o u r n a l of A p p l i e d Physics, Vo[. b3, No. S, pp. 3949-3951 (15 A p t 1988) Magnetic properties, such as domain patterns and anisolropy, welc measured for negative magnetostrictive Co-Si-B amorphous wires exhibiting large Barkhausen discontinuities and the results are compared to those el Fe-Si-B wires with positive magnetostriction. The Co-based wire was found to have a bamboolike domain structure at the wire surface. It was also shown thai the amorphous wires prepared by the in-water quenching technique store tensile stress in the radial direction. The magnctoslrietive anisotropy due to residual stress will produce an axial component of magnetization in conjunction with the two-dimensional geometry of wires making both Co- and Fe-based Wires exhibit large Barkhausen discontinuities along the axis of the wire 38833
Weinstock. H.; Erber, I'.
Training of Barkbausen emission in nickel and iron J o u r n a l of A p p l i e d Physics, Vol. 63, No, 8, pp. 3952-3954 ( 15 Apr. 1988) Barkhausen emission from annealed nickel anti iron was measured with a SQUID gradiometer that could detect magnetization jumps above a noise level of 3 x 10/sup -8/emu. The equipment was installed in a three- axis 12.7 m-diam Braunbeck coil system at NASA's (National Aeronautics and Space Administration) Goddard Space Flight Center. This arrangement provided an overall cancellation of the geomagnetic field to + /0/sup -6/ Oe, and a field homogeneity of 0.001% over a spherical volume of 24.4m/sup ,V. Auxiliary windings in the Braunbeek coils were used to generate uniform magnetizing fields at slow sweep rates. The nickel measurements were carried out in field ranges that interpolated between those used in previous training experiments with iron and gadolinium samples. In all cases, repeated field sweeps eliminated
NDT International February 1989
Jiles, D. C.
The effect of compressive plastic deformation on the magnetic properties of ALSI 4130 steels with various microstructures J o u r n a l of Physics D : A p p l i e d Physics, Vol. 21, No. 7, pp. 1196-1204 (14 Jul. 1988) The magnetic properties of AISI 4130 steel after eight heat treatments have been investigated. Properties such as hysteresis loss, coercivity, and initial permeability were found to be closely interrelated. Furthermore, they were each dependent on the hardness of the material. A relationship between the hardness and permeability was found which was microstructure independent. These parameters were also found to change in a systematic way with plastic deformation and this result can be used for non-destructive evaluation. Correlations between the magnetic parameters revealed relationships which depended on the mierostrueture of the material. The residual stress in steels can be determined from the changes in maximum differential permeability. 38843
Karjalainen, L.P.; Rautioaho, R.H.
Detection of fabrication stresses by the Barkhausen noise method T h e Effects of F a b r i c a t i o n R e l a t e d Stresses on P r o d u c t M a n u f a c t u r e a n d P e r f o r m a n c e , C a m b r i d g e ( U n i t e d K i n g d o m ) , 23-25 Sep. 1985. pp. 149-161. E d i t e d by J.F. A l d e r . T h e W e l d i n g I n s t i t u t e (1987) The high efficiency of the magnetic Barkhausen noise method for qualitative detection of stress changes due to welding, thermal and mechanical stress relief, machining and shot peening in structural steels is demonstrated. The importance of properly adjusting the strength of magnetization is pointed out. The steel composition, metallurgical structure, texture, dislocations and biaxiality of the stress field all affect the inherent Barkhausen noise level and its stress dependence, so that calibration for accurate determination of stress magnitudes does not generally seem reasonable. Examples of the practical applications of the method are briefly outlined. 38842
Jiles, D. C.
Magnetic properties and microstructure of AISI 1000 series carbon steels J o u r n a l of Physics D: A p p l i e d Physics, Vol. 21, No. 7, pp. 1186-1195 (14 Jul. 1988) The magnetic properties of a number of specimens of AISI 1000 series plain carbon steels have been measured as functions of chemical composition, microstructure and heat treatment. The results showed that for a given morphology of the carbides the magnetic properties such as eoercivity and permeability varied smoothly as a function of carbon content. Coercivity increased with carbon content by 2 . 0 0 e for every 0.1 wt% carbon added at low carbon contents while initial permeability decreased by 57% on the addition of 0.2 wt% carbon in the form of lamellar carbides (pearlitc), but by only 21% when those carbides were in the form of spheroidised particles. In all cases the spheroidised specimens were found to be magnetically softer than the lamellar specimens and the difference increased with the amount of carbon present. Grain size did not seem to affect the magnetic properties significantly above a carbon content of 0.2 wt%, although it was known that grain size is a significant factor in determining magnetic properties in iron alloys with lower carbon content. 38841
Ackerman, J.L.; Garrido, L.; Ellingson, W.A.; Weyand,
J.D. The use of NMR imaging to measure porosity and binder distributions in green-state and partially sintered ceramics M a s s a c h u s e t t s G e n e r a l H o s p i t a l , B o s t o n ( U n i t e d States), C O N F 870856-3, D E 8 8 - 0 0 3 0 9 9 , 34 pp. (Sop. 1987) Nonuniformities in porosity or binder distribution in green-state ceramic compacts can lead to failure in the final densified material. NMR imaging is a nondestructive characterization technique, most commonly used in medical diagnosis, which we have adapted for the production of tomographic images of porosity and of binder distributions. We measure open porosity by the imaging of a suitable filler fluid introduced into the part by vaccuum impregnation. Our results on partially sintered bodies show tough correlations with predicted porosity distributions. Results illustrating our techniques in a series el green-state and partially sintered aluminas.
Mikheev, M.N.; Kuleev, V.G.; Nesterenko, V.V.; Rigmant, M.B.; Mikhailovskaya, G.L; Nemkov, V.L.; Lobanova, L.V. 38840
New methods of nondestructive control of the mechanical properties of objects made of medium carbon steels S o v i e t J o u r n a l of N o n d e s t r u c t i v e T e s t i n g , Vol. 23, No. 7, pp. 445-449 ( M a r . 1988) The article suggests a method of nondestructive quality control for heat treated objects, made of medium carbon steels, which may be used in engineering for checking the mechanical properties of objects after hardening and tempering.
Krotov, L.N.; Shleenkov, A.S.; Rozenfel'd, E.V.: Shcherbinin, E.V.; Kop'ev, M.A. 38839
Analysis of ferroprobe operation with a controllable nonlinear electrical resistance in the exciting circuit S o v i e t J o u r n a l of N o n d e s t r u c t i v e T e s t i n g , Vol. 23, No. 7, pp. 455-462 ( M a r . 1988) The theoretical basis for a ferroprobe that has a controllable nonlinear electrical resistance (CNER) in an excitation circuit is discussed.
56
Tabachnik, V.P.; Chernova, G.S.; Fedorishcheva. E.E.; Turetskii, Ya. Sh.
38838
Magnetic inspection parameters of cermet plates containing cobalt Soviet J o u r n a l of N o n d e s t r u c t i v e Testing, Vol. 23, No~ 7, pp. 463-467 (Mar. 1988) Nondestructive inspection for the faces of cermet plates made from type T5K10 alloy is considered according to the normal component of the residual field that is produced by magnetizing an object with an electromagnet with a rod-type core. The relationship between the residual field and the magnetic characteristics of the materials is shown. 38837
Trusov, N.K.: Mel'gui, M.A.: Kulagin, V.N.; Shtdlovskaya.
E.A. Experimental method of determining shear plots in the neutral section of ferromagnetic cylinders made of structural steels Soviet J o u r n a l of N o n d e s t r u c t i v e Testing, Vol. 23, No. 7, pp. 472-477 (Mar. 1988) The article considers and substantiates, both theoretically and experimentally, a method of determining the central demagnetization factor ~! ferromagnetic cylinders made of structural steels and subjected to static magnetization along the anhysterefic magnetization curve 38836
Celasco, M.: Mazzetti, P.; Masoero, A.; Stepanescu, A.
Effects of the viscosity field on the Barkhausen noise of amorphous ferromagnetic materials J o u r n a l of A p p l i e d Physics, Vol. 63, No. ,~. pp. 2983-2985 ( t5 A p r 1988) Contrary to the case of crystalline or polyerystallinc materials, the magnetic aftereffect is almost always present in amorphous ferromagnetic materials. This fact makes the study of its influence very important in order to understand the magnetization dynamics of these materials, which have a growing technological interest. Experimental results prove the existence of a strong correlation between the magnetic aftereffect and the Barkhausen noise. In the present paper a theoretical study of the effect of the viscosity field on the power spectrum of the magnetization noise in amorphous materials will be given. Comparison with the available experimental results will also be made, showing a rather good agreement between theory and experiment 38835
Jiles, D.C.
Integrated on-line instrumentation for simultaneous automated measurement of magnetic field, induction, Barkhansen effect, magnetoacoustic emission, and magnetostriction J o u r n a l of A p p l i e d Physics, Vol. 63, No. 8. pp. 3946-3948 (15 Apr. 1988) A microcomputer-controlled inslrunlent for simultaneous measurement o[ magnetic hysteresis, magnetostricfion, Barkhausen effect, and magnetoacoustic emission is described. It incorporates custom designed software for control of the magnetic field during operations such as demagnetization, field sweeping, and anhysterctic magnetization, and for data logging and analysis. Results are recorded using a 12-bit analog to digital converter and are then stored on floppy disk. The magnetic hysteresis data are converted into six important magnetic parameters: coercivity, remanence, hysteresis loss, initial permeability, maximum differential permeability, and anhysterctic permeability. These, together with the magnetostriction, Barkhausen, and magnetoacoustic emission, are then related to the microstructure of the material.
Yarn~aki, .I.: Humphrey, F.B.: Mohri, K+; Kawamura, H.. Takamure, H.; Maelmhaell, R.
38834
Large Barkhausen discontinuities in Co-based amorphous wires with negative magnetostriction J o u r n a l of A p p l i e d Physics, Vo[. b3, No. S, pp. 3949-3951 (15 A p t 1988) Magnetic properties, such as domain patterns and anisolropy, welc measured for negative magnetostrictive Co-Si-B amorphous wires exhibiting large Barkhausen discontinuities and the results are compared to those el Fe-Si-B wires with positive magnetostriction. The Co-based wire was found to have a bamboolike domain structure at the wire surface. It was also shown thai the amorphous wires prepared by the in-water quenching technique store tensile stress in the radial direction. The magnctoslrietive anisotropy due to residual stress will produce an axial component of magnetization in conjunction with the two-dimensional geometry of wires making both Co- and Fe-based Wires exhibit large Barkhausen discontinuities along the axis of the wire 38833
Weinstock. H.; Erber, I'.
Training of Barkbausen emission in nickel and iron J o u r n a l of A p p l i e d Physics, Vol. 63, No, 8, pp. 3952-3954 ( 15 Apr. 1988) Barkhausen emission from annealed nickel anti iron was measured with a SQUID gradiometer that could detect magnetization jumps above a noise level of 3 x 10/sup -8/emu. The equipment was installed in a three- axis 12.7 m-diam Braunbeck coil system at NASA's (National Aeronautics and Space Administration) Goddard Space Flight Center. This arrangement provided an overall cancellation of the geomagnetic field to + /0/sup -6/ Oe, and a field homogeneity of 0.001% over a spherical volume of 24.4m/sup ,V. Auxiliary windings in the Braunbeek coils were used to generate uniform magnetizing fields at slow sweep rates. The nickel measurements were carried out in field ranges that interpolated between those used in previous training experiments with iron and gadolinium samples. In all cases, repeated field sweeps eliminated
NDT International February 1989