SURFACE TEMPERATURE DIAGNOSIS OF CRACKS ORIGIN IN THE STRENGTH-DEFORMED METALS

Abstract

The results of theoretical studies on the correspondence of the numerical value of the critical density of internal energy to the value of the enthalpy of melting and the structural-energy analogy between the processes of mechanical destruction and melting are analyzed. The physical picture of the distribution of temperature field formed at the time of the birth defect, assuming considered previously investigated defect-free matter and assuming that the temperature redistribution in volume and at the surface is uniform. Analytical and numerical analysis of the heat wavefront arrival created by the growing elemental defect depending on its depth is carried out. The obtained results of the experimental researches with the help of the created control system allowed us to approach the question of prediction of the depth of occurrence of micro defects arising as result of plastic deformation. The calculations have been worked out and practically tested for future applications with the system of external impulse contactless convection perturbation. As a result of studying the temperature-time dependences of the temperature distribution on opposite surfaces of the object of study, and depending on the depth of occurrence of the source of energy changes, the possibility of determining the location of the defect was experimentally determined, provided that the temperature sensors were located in the micro defects zone. For the creation of model quasi-point heating of a real research object corresponding to the model object, a non-contact “quasi-point” heatconvection type heater was developed with the ability to form a temperature difference – up to 100 K/mm. The results of the researches are the basis for the improvement of the existing system of control of the development of microcracks in stressdeformed metal structures.