SU873082A1

SU873082A1 - Method of determination of structural transition temperatures in materials

Info

Publication number: SU873082A1
Application number: SU792852268A
Authority: SU
Inventors: Юрий Федорович Шутилин; Юрий Степанович Балашов; Владимир Васильевич Моисеев; Владимир Сергеевич Шеин; Яков Моисеевич Розиноер
Original assignee: Воронежский технологический институт
Priority date: 1979-11-11
Filing date: 1979-11-11
Publication date: 1981-10-15

Description

1one

Изобретение относитс к технике исследовани структуры и свойств материалов при различных те1 тературах.The invention relates to a technique for studying the structure and properties of materials for various temperatures.

Известны динамические механические методы определени структурных переходов , основанные на оценке затухани механических колебаний в материалах при различных температурах 1.Dynamic mechanical methods for determining structural transitions are known, based on an estimate of the damping of mechanical vibrations in materials at various temperatures 1.

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Однако при этом нагрев образцовHowever, while heating the samples

в ходе эксперимента осуществл ют при помощи специальных термокриокамер, теплообмен в которых осуществл етс конвекцией и лучеиспусканием, а потому наблюдаетс неравномерный прогрев (градиент температур) образцов и мала скорость повышени их температуры . ,.In the course of the experiment, special thermal cryochambers are used, in which heat exchange is carried out by convection and radiation, and therefore uneven heating (temperature gradient) of the samples is observed and the rate of temperature increase is slow. ,

Наиболее близким к предложенному вл етс способ определени температур структурных переходов в материалах , в котором при нагреве измер ют затухание механических колебаний в образце/ укрепленном на основе 21.The closest to the proposed method is the method of determining the temperatures of structural transitions in materials, in which the attenuation of mechanical oscillations in a sample / reinforced on a base 21 is measured during heating.

Однако этот способ не позвол ет нагревать и регулировать температуру быстро и точно и без градиента температур, что снижает скорость и точность определени температур, структурных переходов,However, this method does not allow to heat and regulate the temperature quickly and accurately and without a temperature gradient, which reduces the speed and accuracy of determining temperatures, structural transitions,

Целью изобретени вл етс создание быстрого и точного способа определени температур структурных переходов в материалах.The aim of the invention is to provide a fast and accurate method for determining the temperature of structural transitions in materials.

Поставленна цель достигаетс тем, что в способе, включающем измерение затухани механических колебаний при нагреве образца, укрепленс ного на основе, материал нагревают, The goal is achieved by the fact that in a method involving the measurement of the attenuation of mechanical vibrations upon heating a sample reinforced on a substrate, the material is heated,

10 пропуска электрический ток через основу и одновременно измер 1от затухание колебаний, по которому суд т о температурах структурных переходов.10 passes the electric current through the base and at the same time measures the attenuation of the oscillations by which the temperatures of the structural transitions are judged.

Кроме того,дл исследовани In addition, for research

15 свойств материалов, провод 111их .электричество , ток пропускают через исследуекий материал.15 properties of materials, wire 111. Electric power, current is passed through the test material.

На фиг. 1 приведен пример конкретного исполнени способа по схеме FIG. 1 shows an example of a specific implementation of the method according to the scheme

20 резонансных зычкоилх колебаний; на фиг. 2 - результаты исследовани полистирола по предлагаемому способу.20 resonant oscillations; in fig. 2 - the results of the study of polystyrene by the proposed method.

Образец 1 исследуемого материала крепитс на жесткой основе 2 из кЬн25 стантана. Продольный вырез 3 посередине делит основу на две половины, кажда из которых (фиг. 1, разрез А-А) имеет электрические выводы 4 дл подвода напр жени .питани .. Узел Sample 1 of the test material is mounted on a rigid base 2 of the kHn25 stantan. A longitudinal notch 3 in the middle divides the base into two halves, each of which (Fig. 1, section A-A) has electrical terminals 4 for supplying power. The node

Claims

30 5 serves for piezoelectric swinging and fixing the attenuation of mechanical oscillations of the sample. The measuring system of units 1-5 is placed in a thermocryamer 6. With the help of an electronic unit 7, the sample 1, the bases 2, are swung through the node 5, and the mechanical losses in them are measured. When operating, electric current is passed through base 2 and simultaneously using block 7 and node 5, mechanical vibrations are generated in sample 1 and base 2 connected to it, then the swinging pressure is removed and sample 1 with base 2 makes damped oscillations, which are fixed by node 5 and block 7. Mechanical losses in the oscillation system 1-2 are calculated by the simplified formula, vi l. erft -ir- r where the tangent of the angle of mechanical loss; D is the logarithmic decrement Hell is the amplitude of the initial oscillation; AN is the amplitude of the N-ro oscillation. The mechanical losses are measured during the heating of the samples and the dependence of the mechanical losses on the temperature is constructed, which as an example is shown in FIG. 2 dl polystyrene. The maximum is judged on the temperature of the structural transition, in our example, on the glass transition temperature of polystyrene. The application of the proposed method provides heating of the samples by direct contact between the sample and the heating element, i.e. heat transfer, which is more efficient than convection and radiation used in the known method. At the same time, in the proposed method, it is possible to establish a uniform temperature throughout the entire volume of the test sample more quickly. This reduces the sample warm-up time, i.e. determine more accurately its properties and reduce the duration of the experiment. 1. Method for determining structural temperatures, transitions in materials, in which the temperature is measured during heating. The movement of mechanical vibrations in a sample strengthened on a basis that, in order to quickly and accurately determine the properties, the material is heated, the electric current is passed through the base and the vibration attenuation is measured at the same time, judging by the temperature of structural transitions. 2. A method according to claim 1, characterized in that, in order to investigate electrically conducting materials, an electric current is passed through the test material. Sources of information taken into account during the examination 1. Yanovsky Yu.G. Dynamic mechanical methods for determining structural transitions. Factory Laboratory, vol. 32, 1966, 8, p. 953.

2. Malkin A.Ya. et al. Methods for measuring the mechanical properties of polymers M. Chem., 1978, p. 157160 (prototype).

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