QUALITY MANAGEMENT OF THE BLADES SURFACE LAYER UNDER DEEP PROFILE GRINDING

The article provides the system oriented analysis regarding surface treatment quality after deep profile grinding of complex shapes on a multiaxis machine. This method implies using an algorithm of actions to ensure the quality of deep profile grinding of blades, a mathematical model of heat-dynamic system of a grinding machine in a block diagram form, taking into account the cutting process. The algorithm involves elucidation of the dynamic state of a technological system based on the mathematical model of heat-dynamic system of the grinding machine with consideration of dynamics of elastic, thermal and working processes. The dynamic state of the technological system determines the conditions of deep grinding process. As it is well known, with increasing depth the grinding process can become unstable. In conditions of instability, execution or achievement of specified quality parameters is impossible. To ensure stability of the process it is necessary to receive on the basis of a mathematical model the static and dynamic characteristics which will define the mutual displacement of the grinding disk and a workpiece, the current cutting depth, strength and temperature fluctuations in the cutting zone. The proposed mathematical model allows predicting the removal of material, grinding disk wear and roughness of each surface, based on the cutting modes, characteristics of the disk, dynamics of elastic, heat and work processes in the technological system. Knowledge of the impact of the cutting modes and disk characteristics on the quality of each of the treated surfaces enables to determine analytically the optimal characteristics of the grinding disk and grinding modes to ensure the specified quality parameters of the surface layer of the gas turbine engine blades: surface roughness, physical and mechanical condition (cold hardening, residual stresses), accuracy. This technique allows managing the process of deep profile grinding to achieve the desired surface quality parameters, dimensional accuracy of the profile of the gas turbine engines blades, and increase of processing performance on multi-axis machine of complex shape profiles.