V. F. Matyuk

Magnetization distribution along the cylindrical rod in longitudinal constant uniform magnetic field

The known analytical expressions and experimental data obtained by the authors on the distribution of the cross-section-averaged relative magnetization along a longitudinal solid cylindrical rod magnetized by the uniform field are analyzed. A new calculation formula is offered whose distinctive feature is the allowance for the dependence of the material magnetic characteristics on the field magnetization. Results of calculations and experiments for rods with different geometric parameters and material magnetic characteristics are compared. The applicability of the formula is shown.

A setup for measuring the magnetic characteristics of soft magnetic materials and articles

An automated setup for measuring the normal magnetization curve, the major and minor magnetic-hysteresis loops, and the main (initial permeability, maximum permeability, residual magnetic induction, induction coercive force, and saturation induction) and additional (the permeability at a field equal to the coercive force, the field strength at which the saturation induction is reached, and the induction at fields equal to the coercive force and the double coercive force) magnetic parameters of soft magnetic materials and articles produced from them is described. Measurements are performed in an open or closed magnetic circuit at a magnetization-reversal frequency of 0.05–0.5 Hz. The block diagram of the setup and its main parameters and characteristics are presented. The operation of the setup and the possibilities of its application are considered.

IMA-4M pulsed magnetic analyzer

The effect of the instability of the rear edge of magnetizing pulses on the results of testing by means of the pulsed magnetic method is considered. A description is given for a new IMA-4M device for magnetic testing of products fabricated from low-carbon steels and certain middle-carbon and low-alloy cold-rolled and hot-rolled steels of thickness up to 4 mm. A box-diagram and technical characteristics of the device are given.

The IMA-6 pulsed magnetic analyzer

The principle of construction of the IMA-6 pulsed magnetic analyzer for testing the quality of thermal treatment, the mechanical properties, and the microstructure of articles of low-carbon, medium-carbon, and low-alloyed cold- and hot-rolled steels is described. The structural scheme, the performance characteristics, and examples of application of the instrument are presented.

Optimization of dimensions of a device for circular magnetization of cylindrical components. III. Investigation of circular field component generated by a one-layer toroidal coil

The effect of dimensions of a toroidal coil and the number of turns in the coil on the circular magnetic field component within the region limited by the inside axial sections of the turns has been studied. The configuration of this field has been determined. Optimal dimensions of the coil have been calculated. In order to obtain a higher amplitude of the circular field, one should use coils with smaller numbers of turns. In the inner region of a one-layer toroidal coil close to the turns, the peaks of the circular field diminish with the number of turns, but the number of points where the field intensity is maximal becomes larger, i.e., the field becomes more uniform. Methods of further increase in the circular component of the magnetic field have been suggested.

Distribution of residual magnetic induction along a solid circular core magnetized in longitudinal constant homogeneous magnetic field

An amalysis of the data obtained experimentally and by numerical computation on the distribution of residual magnetic induction averaged in a cross section along the longitudinal axis of a solid circular core magnetized by a constant homogeneous magnetic field is given. A new calculation formula that takesinto account the dependence of the magnetic material characteristics on the value of the magnetizing field is proposed. The calculation and experimental data are compared for cores with various geometries and magnetic material characteristics. The area of applications for the formula is shown.

Distribution of Magnetic Induction Along Hollow Core of Round Section in Constant Homogeneous Magnetic Field

The results and an analysis of experimental studies of the distribution of the average relative magnetic induction in the cross section along the longitudinal axis of a hollow cylindrical ferromagnetic core of a round section magnetized by a homogeneous constant magnetic field are presented. A new formula is presented for calculations that take into consideration the thickness of the wall of the core and the dependence of the magnetic characteristics of its material on the size of the magnetizing field. A comparison has been made of the results of calculations and experiments for hollow cores of different geometries and the various magnetic characteristics of a material in a wide range of changes in the magnetizing field. The scope of the formula is shown.

Central demagnetization coefficient for hollow cylindrical bars made of soft magnetic materials

A new formula is proposed for calculation of the central demagnetization coefficient for hollow cylindrical bars made of soft magnetic materials. The nonuniformity of the demagnetizing field was taken into account by means of averaging, over the volume, the density of fictitious magnetic charges on the surface of the hollow bar and using an empirical expression for the magnetization distribution over the surface. The calculations performed according to the proposed formula are compared to experimental data, including those obtained by other authors. The new formula is shown to be applicable to the calculation of the central demagnetization coefficient for hollow cylindrical bars made of soft magnetic materials in a broad range of bar dimensions.

Optimization of dimensions of a device for circular magnetization of cylindrical components. IV. Investigation of circular magnetizing field generated by a multilayered toroidal coil

The effect of dimensions of a toroidal coil, the number of turns and layers in its winding on the circular field component generated in its inside volume defined by the inside axial sections of the turns has been investigated. The configuration of the field in this region has been calculated, and the principles of the design of magnetizing coils have been formulated. In order to obtain a higher circular field intensity in the region close to the turns, it is advisable to use multilayered windings. A fairly uniform circular field is generated in a local region if the winding is divided into equal sectors containing zones with turns of wire and gaps between them. In order to obtain a circular field component of a relatively high intensity and a constant sign over a wide sector of the inside volume, one should build a coil of several sections uniformly distributed over the frame perimeter.

Distribution of the residual magnetic induction along a hollow cylindrical core magnetized by a longitudinal homogeneous static magnetic field

Experimental and numerical data on the distribution of the cross-section-averaged relative residual magnetic induction along the longitudinal axis of a hollow cylindrical core magnetized by a homogeneous static field obtained by the authors were analyzed. A new calculation formula was proposed. A distinguishing feature of this formula is that it takes into consideration the thickness of the core’s wall and the dependence of the magnetic properties of the material on the magnetizing field. A comparison between the numerical results and the experimental data for cores of different geometries manufactured of materials with different magnetic properties was made. The application area of the proposed formula was shown.