V. G. Sloushch

Dependence of the dielectric properties, porosity, and apparent density of quartz ceramic on the phase of composition

ConclusionsIt has been established that there is a connection between the porosity, the apparent density, and the concentration of cristobalite and the dielectric constant of a quartz ceramic; this connection may be used to carry out on-line, nondestructive monitoring of quality.A reduction in porosity of the quartz ceramic associated with an increase in temperature is accompanied by an increase in the concentration of cristobalite. In the experimental quartz ceramic a significant amount of cristobalite (>5%) appears with a porosity <13%.

The relationship between the thermoplastic and the dielectric properties of oxide refractories

ConclusionsThe interrelationship between the deformation rate and the dielectric properties of Al2O3- and MgO-base refractory materials was investigated. An empirical relationship making it possible to compare the deformation rate of different refractory materials with their dielectric characteristics was obtained.

Evaluating the technological properties of powders from their dielectric permeability

ConclusionsWe established the presence of a link between the activity of powders determined by measuring their dielectric permeability and the thermomechanical properties of the specimens.On the basis of the measurements of the dielectric permeability it is possible to assess operationally the technological properties of powders used for preparing bodies.

Dielectric constant of refractory articles

ConclusionsThe values of the real dielectric constant of refractory articles over a wide range of change in their apparent density (0.6–4.2 g/cm3) and chemical composition have been experimentally determined. The presence of a connection between the dielectric constant and the properties traditionally determined during the certification of a refractory article is demonstrated. On the basis of the measurement of the dielectric constant it is possible to obtain information on the material composition and structure of articles, on-line and without destruction. The information can be used to monitor the quality of the product or for instrumental (objective) grading of articles according to their properties.

Checking the structure of fusion-cast baddeleyite-corundum BKCh products with the radio-wave method

ConclusionsOwing to the large dimensions and weight and also the high cost of BKCh articles, they should be quality controlled by nondestructive methods of the radiowave type. In the first case this method is useful for selecting BKCh articles for the most critical elements of the structure, e.g., the channel of tank furnaces.

A radio-wave study of periclase tiles for the sliding gates of steel-casting buckets

ConclusionsA connection has been established between the dielectric constant ε0 of the framework of periclase bushings (nonporous part) and the structure, sintering processes, and the behavior of the bushings during service.By radio-wave illumination of the refractory products, it was possible to obtain information on the structures of these articles. Using radio-wave refractometry it was established that the grain composition of the mass (batch), the temperature, and the firing regime all have a significant effect on the structure of the bushing; the connection between the structure and the behavior of the bushings in service has been studied.The use of radio-wave refractometry is an effective and useful means of adjusting the production process and stabilizing the properties of the articles and also for conducting a nondestructive monitoring of the quality of the production.

Radio wave phase method of quality control for refractory slabs for sliding gates

ConclusionsThe radio-wave method can be used for operative control of the open porosity P, the apparent density ρ, and the density variation in refractory slabs for sliding-gate steel-pouring valves. The error in determining P is not more than 1 abs. %, and that in determining ρ is not more than 0.03 g/cm3.With the aim of improving the quality of production, it is recommended that the radiowave phase method should be used for nondestructive testing of the finished slabs and also of semifinished articles at intermediate stages of manufacture.

Use of microwave electromagnetic oscillations for nondestructive testing of refractories

ConclusionsThe microwave method of quality control facilitates the local and integral checking of the apparent density and porosity of products having different shapes, and also the checking of products having different densities, without breaking the refractories.The high accuracy, the low effect of the masking factors, the noncontacting nature, the simplicity of automating the testing procedure, and the high speed (parts of a second), make the microwave method very promising for checking the apparent density and porosity of refractories.

Levels for free-flowing materials

ConclusionsThe following levels can be recommended for use in the refractory industry: SUP-IO-4, SUF-IO-9, ES-1000, ES-1001, and the tracing levels US-IO-1 and US-IO-2.Mass production of position and tracing levels of the given type should definitely be organized.