**2. Magnetodielectric materials**

These materials are composite materials made of magnetic particles and dielectric materials that serve as links and electrical insulators of magnetic particles. Magnetic properties of magnetodielectric materials (MDM), depend on constituent particle properties, their shape and volume. Mechanical and thermal characteristics depend mainly on the ratio of magnetic material, and dielectric material. The general properties of materials depend by manufacture technology, their achievement, given the fact that their production involves a pressing process, who making certain properties, especially magnetic to manifest differently on different axes.

The world leader in the manufacture of MDM is FLUXTROL Company, which made several types of magnetodielectric materials [6].

In those that follow will present the results of several studies made by the authors, to obtain a magnetodielectric material by using it in inductive heating processes.

To achieve magnetodielectric material was used dielectric material, consisting of two components manufactured epoxipoliamidic resin without solvents, that drying to 80 C.

Mixing ratio of components A / B is 2/1 parts by weight. The product is used in electrical engineering, as mass of hardware, building and construction fill in some details of engines

#### 82 Dielectric Material

and generators, to strengthen the drum and clutch electromagnetic coil for sticking carcasses and broken cylinders from large and small electrical transformators.

Magnetodielectric Materials – Use in Inductive Heating Process 83

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

The dimension of the rectangular plaque are :

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

MDM in a thermostatic oven, it was repeat.

shown in Figure 6.

The results are presented in the following table.

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

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

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

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

Figure 5

Technical characteristics of electro-mass (dielectric material):

a. Features delivery


#### **Table 1.**


Processability time: 30 min.
