ИССЛЕДОВАНИЕ ВЛИЯНИЯ ЦЕЛЕВОГО МОДИФИЦИРОВАНИЯ ЭПОКСИДНЫХ МАТРИЦ И УГЛЕПЛАСТИКОВ НА ИХ ОСНОВЕ НА ТЕМПЕРАТУРУ В ЗОНЕ РЕЗАНИЯ ПРИ ОБРАЗОВАНИИ ОТВЕРСТИЙ

Abstract

PURPOSE. The paper studies the effect of the special modification of epoxy matrices and epoxy matrix-based polymer composites on thermophysical parameters of machining processes under hole formation. A goal is set to produce experimental samples from matrices and experimental panels from carbon fiber plastics based on modified matrices. It is necessary to reveal whether there is any dependence of machining process thermal effects on the modification degree of matrices and carbon fiber plastics. METHODS. Experimental methods are used to achieve the purposes of this work. The experiment includes: production of experimental panels (binder preparation, liquid-phase combination with a dry filler, impregnation and vacuum-pressure oxidation molding); checking of their quality and mechanical properties (non-destructive testing of experimental panels by acoustic methods and standard mechanical tests); measurement of the cutting temperature under hole drilling in the sample made of experimental panels (infrared thermography of the hole formation zone). RESULTS AND THEIR DISCUSSION. It has been determined that the matrix samples feature the lowest heat release in the intervals from 0.1 to 0.3% wt depending on the type of the tool used. The peaks of the lowest heat release of the matrix-based carbon plastic samples are shifted to the range from 0.2 to 0.5%. The decrease in the maximum temperature in these ranges is due to the antifriction properties of the zinc stearate modifier: the coefficient and friction forces are reduced. Further increase in the modifier concentration leads to the recovery or even excess of the thermal effects relative to the initial unmodified matrices and carbon fiber plastics (0 % zinc stearate). This fact can presumably be explained by the decrease in cutting efficiency at reduced friction coefficients. The shifts of the peaks to the right and their “widening” for carbon fiber plastic samples is probably related to the thermophysical properties of the filler, which change the conditions of heat removal from the contact zone of friction bodies (a part and a processing tool). It is the carbon fiber plastic that is of some practical interest being a composite combination of a matrix and a carbon filler, which demonstrates more advantageous values of the thermal parameters of machining processes according to the study results. CONCLUSIONS. It has been shown that modification does not have any negative effect on the mechanical properties of modified composition-based carbon plastic. The dependences of the thermal effects of the machining processes under the hole formation in the samples on zinc stearate modifier concentration have been revealed. This fact proves the effectiveness of modification.