THE DESTRUCTIVE THERMOELASTIC STRESSES CAUSED BY HEAT OUTPUT IN GAZ INCLUSIONS IN COMPOSITE MATERIALS

The paper considers such important phenomenon in radio components as the cleavage in multicomponent materials. Composite materials are the important class of radio materials, thus the improvement of complex of their properties has the important fundamental and applied significance and is the up-to-date sector of the material science. The improvement of composite materials contributes to their wider application and production of new radio components. Alongside with the composite materials properties’ improvement, the compounds where other elements, for example, rare-earth (alloys with praseodymium or samarium) are applied are of considerable interest. The paper studies the influence of thermoelastic stresses on the performance capacity of radio components containing composite materials, identifies physical factors influencing most greatly the operational suitability of the products with the composite materials. The author had an objective to study the mechanisms of initiation and behavior of a thermoelastic breakdown in a composite material containing the inclusions, in particular, air inclusions. For example, metal-based composite material contains dozens of inclusions of various compositions. As a rule, composite materials contain air inclusions the influence of which should be taken into account as well. The electrical strength and the service life of the details produced from the non-homogeneous composite materials within the strong electric fields depend on the content of air inclusions and their shape. The paper presents the calculation of the electric field strength in the inclusions and near them. The author considered the process taking place in an ellipsoidal inclusion under the influence of strong electric field and analyzed the relative influence of large inclusions’ shape on the hardening mechanism. The processes for small and large inclusions in a composite material and their influence on the destruction of the details caused by the discharges in the inclusions are considered separately. The influence of complex external action (different temperatures, etc.) is studied. It is identified that the heat generation caused in the strong high-frequency fields by the ionization in air inclusions in composite materials can be significant and, under the strong external actions, the destructive stresses can occur. The uneven heating of a composite material leads to the appearance of destructive thermoelastic stresses and to the cleavage of radio components caused by the heat generation in large inclusions.