STUDYING THE INFLUENCE OF THERMOMECHANICAL PHENOMENA ON GRINDED SURFACE QUALITY PARAMETERS OF PRODUCTS MADE FROM HARD-TO-PROCESS MATERIALS

Grinded surface quality state of products made from hard-to-process materials is formed under the influence of thermomechanical phenomena during final machining operations. But grinding causes the formation of burns, cracks, and tensile stresses in surface layers of products. These defects significantly influence reliability and durability of products during their operation. High thermal tension of diamond-abrasive processing leads to the fact that thermophysics of these processes is dominating in formation of quality characteristics of processed surface. Existing grinding methods for products made from hard-to-process materials do not allow to fully eliminate defects that occur in surface layer. Among the factors that conduce these defects are inevitable fluctuations of processing allowance, microheterogenity of the material characterized by the size of grain, packaging defects, structural transformations and dislocations, product warping during thermal treating, insufficiently studied thermomechanical phenomena. The mentioned effects accompany grinding process and cause burn marks, microcracks, structural transformations, residual stresses. Exploration of thermomechanical phenomena that form the quality of surface layer considering preceding machining operations of products, determining their influence on cracks and burns formation based on quality analysis of thermal and stress states and make up the objective of this research. This paper proposes more efficient models for studying quantitative connections between technological system parameters, physical and mechanical properties of processed materials, their structure, and thermomechanical processes during grinding. We have developed optimal technological parameters for processing metals and alloys prone to defects in surface layer based on determined relationships. Such defects encompass defects like cracks, burns, and chips.