SU1670572A1 - Method of non-destructive control of physical and mechanical parameters of conductance materials - Google Patents

Abstract

The invention relates to non-destructive testing and can be used to control the characteristics of electrically conductive composite materials. The aim of the invention is to improve the accuracy and broaden the scope of use by also controlling the physicomechanical parameters of composite materials by taking into account variations in material properties and / or manufacturing technology for products made from it. The controlled material parameter is determined through analytical and correction functions after determining the monitored parameters and specific electrical conductivities of the material, respectively, of the reference sample and technological pass of the controlled material, as well as the specific conductivity of the material of the controlled product, the material of the reference sample and the material of the technological allowance of the controlled product.

Description

one

(21) 4456139/28

(22) 07.06.88

(46) 08/15/91. Bul №30

(72) L.T. Berezhnytskyi, N.G.Stashchuk, Yu.A.Kolevatov, V.A. Pepelev, V.G. Vezdeneev and

E.A. Grandma's

(53) 620.179.14 (088.8)

(56) Handbook. Non destructive testing of metals and products. - Ed. G.S. Samoylovich. M .: Mashinostroenie, 1976, p. 221-223.

(54) METHOD OF NON-DESTRUCTIVE CONTROL OF THE PHYSICAL AND MECHANICAL PARAMETERS OF ELECTROCONDUCTING MATERIALS

(57) The invention relates to non-destructive testing and can be used to control the characteristics of electrically conductive composite materials. The aim of the invention is to improve the accuracy and broaden the scope of use by also controlling the physicomechanical parameters of composite materials by taking into account variations in material properties and / or manufacturing technology for products made from it. The controlled material parameter is determined through analytical and correction functions after determining the monitored parameters and specific electrical conductivities of the material, respectively, of the reference sample and technological allowance of the controlled material, as well as the specific conductivity of the material of the controlled product, the material of the reference sample and the material of the technological allowance of the controlled product. 1 tab.

WITH/

WITH

The invention relates to non-destructive testing and can be used to control the characteristics of electrically conductive composite materials.

The purpose of the invention is to improve the accuracy and expansion of the field of use due to the control also of the physicomechanical parameters of composite materials by taking into account variations in the properties of the material and / or the technology of manufacturing products from it.

The method consists in determining the characteristics of a material based on its conductivity.

The control method is implemented as follows.

Determine the specific conductivity Oe of a reference sample having

the maximum value of the monitored parameter G for a given material, the specific conductivity Gn of the material of the process allowance of the product being monitored, the values of the monitored parameter Сe and Gn of the material of the reference sample and the material of the allowance, respectively, then measure the specific conductivity (7K of the material of the product under test)

 (Ј), Ј (approx. C „)}, (1)

4V

-Where fQj-), Ј (an, Gn), - analytical and correction functions, respectively, determine the value of the controlled parameter G.

In determining the shear modulus, relation (1) is written as

where G, G3, Gn is the material shear modulus at the controlled point, the material of the reference sample, technological allowance of the controlled part, respectively;

Station Oe, Op - specific electrical conductivity of the material at a controlled point, the material of the reference sample, technological allowance of the controlled part, respectively.

An increase in the accuracy of control is achieved by adjusting the parameters of the ratio (diagnostic model) implemented in the control of each product and thereby maintaining its level of adequacy without changing the type of functional dependencies and the entire mathematical structure. The greatest increase in accuracy is achieved in those cases where unexpected deviations of the composition of the material or the technology of manufacturing the product cause, as a result, such changes in the controlled characteristics that their values fall outside the range of values

SRI.

In addition, by varying the value of the controlled parameter determined by the ratio, one can judge about the heterogeneity of material properties within one product, and by varying the values of the correction function Ј ((Jn, Gn) included in the ratio), one can estimate the heterogeneity of properties from product product, and indirectly, technology instability.

An example of the implementation of the method in determining the shear modulus of a carbon material in a product (measurements of the specific conductivity were carried out using a whirling meter Multicore).

On a preselected material of this type with a shear modulus corresponding to the maximum modulus value for this material, the specific electrical conductivity Oe is determined, after which the actual value of the shear modulus Се of the material is determined by mechanical tests of the sample material (reference). These values are

a, (385 ± 1 1) MSm / m /

G3 (8630 ± 259) MPa.

The specified values of Oe, G9 are determined once to control all products from this material, then these values are used as constants.

To determine the shear modulus of the material of a particular product, it is determined on the technological allowance of this product, the specific conductivity of it, then the method of mechanical tests is the shear modulus Gn of the material in the areas of conductivity measurement: an (295 ± 9У10 4MSm / m,

Gn (7405 ± 5J8) MPa.

The measurement of the electrical conductivity of the material of the product itself (in points) is carried out, after which, using the expression

,but

(j |) + (Oh.Gn)

where analytical and corrective functions are obtained on the basis of solving theoretical problems of determining the electrical conductivity of a composite material with regard to the structure, geometry, the presence of pores in the material and have the form

(A. 3 (1-2u) and Oe 3

(1- |) 3Gn

2 V2

Ј (oh.Gn) g-f (g),

calculate the values of the shear modulus at the points of electrical conductivity control on the product.

Samples of shear moduli were determined from the control sections of the product to estimate the error of the method and mechanical tests (three-point bending method).

The measurement results and relative errors are listed in the table.

Claims (1)

The invention method of non-destructive testing of the physicomechanical parameters of electrically conductive materials, which consists in determining on the reference sample the magnitude of the specific electrical conductivity Oe and the corresponding value of the controlled parameter Ce, determining the specific electrical conductivity of the coated material and using the obtained values for determining the controlled parameter, characterized by the fact that, in order to increase the accuracy and expand the field of use due to the control also of the physicomechanical parameters of composite materials, a reference sample is used with a maximum value for a given material of the controlled parameter, the values of controlled the parameter Gn and the specific conductivity On of the material of the technological allowance of the controlled product and the value of the controlled parameter 6 of the controlled product are determined from the ratio -2y) + From „0n-S% J 1 | t- Where I I / H / D1L / JOI 1WI V / I go product op ( & Have "Tz Wv (-s)