SU1318883A1 - Method of checking thermal physical characteristics of material - Google Patents

Abstract

The invention relates to the indestructible control of the thermophysical properties of materials with a porosity of 80%. The aim of the invention is to increase the performance of the control of the coefficient of thermal conductivity and the expansion of technological capabilities. The purpose of the invention is achieved by the fact that the regression dependence between the thermal conductivity coefficient of tiles made of thermal insulation material (TIM) and the depth of indentation of the indenter into the material is previously revealed. Indpection is carried out in the direction of the heat flux at a constant level of mechanical load on the nndentor, and the controlled parameter is calculated from the regression dependence. 1 il. with (L with 00 00 00 with

Description

one

The invention relates to non-destructive testing of the thermophysical properties of materials with a porosity in excess of 80%,

The goal of the invention is to expand the tenological possibilities in controlling materials with high porosity and increasing productivity.

The drawing shows the regression dependence of the coefficient of thermal conductivity of the material with the depth of penetration of the indenter into the material, where 1 is the coefficient of thermal conductivity of the material, w / m K; h is the depth of penetration of the indenter into the material, mm; R - correlating coefficient

tion; t - Student's t test, calculated from experimental data.

The method is carried out as follows.

20 tiles are prepared from a thermally insulating material based on a quartz filler with a length, width and height of 200 200 x 100 mm, respectively.

. In each tile of TIM, opposite large edges are identified with a fixed load of 2 kgf on the indenter ball with a diameter of 9 mm. In this case, the value of h is determined as the arithmetic average of six measurements (three on opposite large faces parallel to the base of the tile).

Then, six samples are drawn from each tile to determine the average value of the heat conductivity coefficient of the tile. Samples of size 100 v 100 8 mm (length, width and height, respectively) are also cut parallel to the base of the tile. The thermal conductivity coefficient of the samples is measured on an IT-4 instrument, which allows it to be determined in a wide range of temperatures, both high and low.

Further, on the basis of the correlation-regressive analysis of experimental

the data are given a regression relationship connecting the thermal conductivity coefficient L with the depth h.

From the analysis of the drawing, it follows that the regression dependence has a high correlation coefficient (R 0.926), and the evaluation by Student's criterion substantially exceeds its tabular value.

 2,086 (t

mark, h-xpx 9,397),

those. characterized as very significant.

This dependence is used as a working when controlling the coefficient of thermal conductivity of materials at 40 ° C. For determining the coefficient of thermal conductivity at other temperatures, it is necessary in each case to identify the corresponding dependences of A on h.

Claims (1)

Invention Formula The method of controlling the thermal conductivity of materials by exposure to heat flux, which is - with the aim of expansion of technological capabilities in the control of materials with high porosity and increase in productivity, on a series of control samples establish a regression the dependence between the thermal conductivity and the depth of the indenter insertion, indentation of the sample from the material under test in the direction of the heat flow is carried out, the depth of the indenter insertion is measured, and the coefficient of thermal conductivity is determined by the formula Where  & h coefficient of thermal conductivity of the material; Depth of the indenter; the free term and the equation coefficient, respectively. , tnJM- + + -"four + + five / / .; n / -3