**3. Experimental determination of magnetodielectric material resistivity**

To achieve the intended purpose of the topic to increasing power conversion efficiency in the heat study was done to achieve magnetodielectric material samples based on ferromagnetic particles, embedded in electro-mass.

In the first phase of research was done a rectangular plaque, the dimension of them it is shown in Figure 4.

**Figure 4.** The dimension of the rectangular plaque

The dimension of the rectangular plaque are :

 L = 46,6 mm l = 16,5 mm h = 8,2 mm

82 Dielectric Material

**Table 1.**

**Table 2.**

**Table 3.**

a. Features delivery

and generators, to strengthen the drum and clutch electromagnetic coil for sticking carcasses

Features delivery A Component B Component Aspect Mush mass Mush mass Colour gray gray Specific weight [g/cm3] 1.7 - 1.5 1.25-1.30

and broken cylinders from large and small electrical transformators.

Technical characteristics of electro-mass (dielectric material):

Curing time at: 23C is 8 hours 80C is 1 hours 120C is 30 minute

b. Mechanical properties of hardened product

Tensile resistance [kgf/cm] 190 Compresion resistance[kgf/cm] 800 Bend resistance [kgf/cm] 200

dielectric rigidity [kV/mm] 14 Surface resistivity [] 5\*1012 Volume resistivity [cm] 3\*1014

Characteristics were determined on specimens cold hardened for 7 days

ferromagnetic particles, embedded in electro-mass.

**3. Experimental determination of magnetodielectric material resistivity** 

To achieve the intended purpose of the topic to increasing power conversion efficiency in the heat study was done to achieve magnetodielectric material samples based on

In the first phase of research was done a rectangular plaque, the dimension of them it is

Processability time: 30 min.

Mechanical properties

c. Electrical properties

Electrical properties

shown in Figure 4.

The magnetodielectric material was made by mixing the ferromagnetic metal powder 68%, with 32% resin of the type shown in the previous subsection. Material sample is placed between rectangular form electrodes of a measuring device whose scheme is shown in Figure 5

**Figure 5.** Module scheme used to determine resistivity value

The supply voltage is set at 100V and it was make determinations of the resistance of the sample and on the base of the sample size it was calculated the material resistivity. The determination, at different temperatures of the ambient, by heating the specimen of the MDM in a thermostatic oven, it was repeat.

The results are presented in the following table.

Average values of the coefficient of variation of resistivity with temperature, is α = 51,10

Curve of variation of resistivity with temperature, obtained for this type of material is shown in Figure 6.


Magnetodielectric Materials – Use in Inductive Heating Process 85

(2)

(3)

The dimension of the thoroidal sample is:

Number of turns in primary :N1= 368 Number of turns in secondary :N2= 1

Scheme used to determine the dependence B = f (H) is shown in Figure 8

1 *m N I <sup>A</sup> <sup>H</sup>* 

 *D m* 

<sup>2</sup> 2

Figure 9 show the first magnetization. With [\*] are the values which have been determined

Given the advantages of concentrator field magnetodielectric materials, in this case study was modeled an inductor, witch use a concentrator field made by magnetodielectric material, by the type obtained, by using modeling and numerical simulation with FLUX2D

The field concentrator made of magnetodielectric material, have the following materials data:

*N S*

*B*

where S is the section of the toroidal core magnetodielectric material.

Measured and calculated values are presented in the table 5.

**5. Inductor modeling with field concentrator** 


**Figure 8.** Scheme used to determine the dependence B = f (H)

and magnetic flux density is given by the expression:

Magnetic field is calculated with relation:

from measurements

software[4].

De = 46 mm Di = 34 mm Dm = 40 mm a = 6mm b = 6mm

**Table 4.**

**Figure 6.** Variation of resistivity with temperature
