METHOD FOR ANALYZING MATERIAL DEFORMATION Russian patent published in 2018 - IPC G01N3/08 

FIELD: measurement technology.

SUBSTANCE: invention relates to optical methods for measuring deformations in the field of analyzing mechanical properties of materials, in particular tool steels and hard alloys, by applying compressive static loads. In the method for analyzing deformations of material, one of the side faces of the test sample and the surface of the movable press plate, facing the fixed plate, are polished. Electrodes are arranged on the outside of the press plates. Semiconductor layer is inserted between one of the plates and the corresponding electrode. Sample is installed between the press plates. Mirror-polished surfaces of the sample and movable plate are exposed to beams of coherent monochromatic laser radiation, wherein the above surfaces are located in the working arms of two-arm interferometers, which are used to form interference patterns. Wherein to record the change in the sample length by measuring the distance between the press plates, the beam of the working arm of the longitudinal interferometer is directed to the mirror-polished surface of the movable plate through a mirror polished surface, that has been previously arranged on a stationary plate at an angle of 45 degrees. Sample is preloaded. Constant electric current is passed between the electrodes, wherein when the said constant electric current passes through the semiconductor layer, heat is generated, which heats the sample. During the test, the sample is deformed, the temperature of the sample and the loading force P are continuously measured, and the numbers of interference lines are calculated by means of photodetectors, and the results of measurements are recorded and processed on a PC. Deformations of the material are determined by using changes the interference patterns, and the former are used to determine the elastic modulus E and Poisson's ratio.

EFFECT: increased accuracy of measurements of the elastic constants of a material at high temperatures.

1 cl, 2 dwg