SU1305591A1 - Method of checking linear thermal shrinkage of materials - Google Patents

Abstract

This invention relates to acoustic methods of non-destructive control ROL. The aim of the invention is to increase the reliability and accuracy of control of materials subjected to firing in the manufacturing process, due to taking into account the change in the technological conditions of material production due to the additional measurement of water content per unit volume of the formed material before firing. Before calcining the material, the water content is measured in a unit volume, and after calcination, the rate of propagation of ultrasonic vibrations in the material is perpendicular to the direction of the controlled thermal shrinkage. Then, using the measured values, the monitored parameter is determined using the calibration dependence. he ate

Description

1130

The invention relates to acoustic methods of non-destructive testing and can be used to control linear thermal shrinkage of materials, in particular, thermal insulation materials with a porosity of 80% based on quartz filler.

The purpose of the invention is to increase the reliability and accuracy of control of materials subjected to the process of manufacturing Lenin by burning, by taking into account changes in the technological conditions of production of the material.

The method of controlling the linear thermal shrinkage of materials is as follows.

.... f

The water content is measured in a unit volume of the decorated material before firing. Then, after firing the material, ultrasonic (US) vibrations are emitted into it perpendicular to the direction of thermal shrinkage, ultrasonic vibrations that have passed the base distance in the material are taken, and the ultrasonic propagation velocity is measured. fluctuations in the material. The controlled parameter — linear thermal shrinkage — is determined from the rate of propagation of ultrasonic vibrations and the water content in the controlled material, taking into account the calibration dependence.

The method of controlling linear thermal shrinkage of y is implemented as follows.

In the production of tiles of insulating material, for example, based on quartz filler, the raw material is used in a moist form to facilitate the decorating process. After registration, the tile is weighed, dried at a temperature above 100 ° C for a predetermined time, and weighed again. The difference in the weight of the tile before and after drying, related to the volume of the tile after decoration, determines the water content W per unit volume of the decorated material of the tile, from which it is also possible to determine the porosity of this material. After this, according to the technological process, the tiles are subjected to firing at a given temperature in a no-time mode. Then, ultrasonic vibrations are emitted into the material, for example, with a frequency of 60 kHz perpendicular to the direction of thermal shrinkage of interest, ultrasonic vibrations that have passed the basic distance in the mater

rial, and measure, for example, using the device UK-10I, the velocity .V of the propagation of ultrasonic vibrations.

According to a previously determined calibration dependence, for example,

, V + a2W,

where a, a, and a are experimentally defined constants,

and by measuring the values of W and V, linear thermal shrinkage y is determined.

Thermal insulation material based on quartz filler is a globular structure with a pronounced transverse isotropy of physicomechanical characteristics. There is a stronger, more resilient direction parallel to the base of the tile (perpendicular to the pressing force) and a weaker less elastic direction perpendicular to the base of the tile (parallel to the pressing force). According to the results of the experiment on 17 samples, it was found that for the correlation dependence of the type

 Xt

- y,

where y is the linear thermal shrinkage of the heat insulating material in a weak direction. after a 16-hour hold at temperature

%;

V propagation velocity

Ultrasonic vibrations in strong

direction, m / s,

the correlation coefficient is 0.919, the mean square deviation from the regression line is 0.553.

For correlation type dependence

, Y

the correlation coefficient is 0.853, the mean square deviation from the regression line is 0.679.

For correlation type dependence

, -a,

coefficient (| patient multiple correlation 0.967, standard deviation S 0.504.

In the latter case, the experimental Fisher test, 2 is much more than the tabular value of 0.504. A correlation is also obtained for linear shrinkage in a strong direction with a velocity

313055914

the propagation of ultrasonic vibrations in the spruce is determined by the controllable

bom direction and water content is a parameter

in a unit of volume drawn up by the fact that, in order to increase the

rial, for which R "0,897,, 624, the nosti and accuracy of control materials,

, 7.5 subjected to the manufacturing process

Claims (1)

Claims of the invention, the water content is additionally measured in a unit volume by the method of controlling a linear thermal material before it is burned, measuring material shrinkage, the rate of propagation is realized by measuring the rate of fOl after firing, and the linear The propagation of ultrasonic cola-thermal shrinkage is determined by tampering in the material perpendicular to the non-dependence depending on the direction of thermal shrinkage and lethal quantities.