Experimental study of the relationship between the vibro-acoustic parameters of the grinding process and the macro-roughness of the treated surface

OBRABOTKAMETALLOV Vol. 23 No. 3 2021 technology More recent experimental studies of the wear of grinding wheels [13] qualitatively confirm the presence of the initial and normal stages of the abrasive grain wear rate using the example of changes in the size of the blunting areas of the grinding wheel 1 600×50×305 24А F60 L 7 V 50 2cl GOST R 52781–2007 (Fig. 4 [18]). A stage of acceleration in blunting areas and a stage of a moderate rate of increase in wear areas are clearly marked for various feeds. The authors also determined the time values for GW with different characteristics corresponding to the duration of the initial stage. Fig. 4. Curves of dependences of the size of the blunting area for different feeds over time The data obtained during the experiment are consistent with [13, 16–18]. It is definite that an increase in the sound level correlates with an increase in the blunting areas during grinding; there are similar divisions of the characteristic stages of the behavior of the sound parameters and wear indicators of the GW over time. A correlation and regression analysis of the experimental data on the features of the acoustics accompanying the grinding process is explained by the need to transform the qualitative dependences into a mathematical form. After performing a number of calculations using mathematical statistics techniques, a multiple linear regression model was obtained that establishes the relationship between the factors of the in-out feed rate (SP, mm / min) and the operating time of the GW (t, min) and the sound level parameter (β, dB): β = − + ⋅ + ⋅ 56.5 15.4 4.5 . R S t (1) The significance of the regression model is verified using Fisher’s criterion. The table value of Fisher’s criterion for the significance level P = 0.05 and the values of the degrees of freedom = 2 R f and = 77 e f is = 3.115 table F . = =  115.2 3.115. cal table F F (2) Since the calculated value of Fisher’s criterion is much larger than the table value, we can conclude that the regression equation is statistically significant and can be used to determine and predict the sound level value depending on the in-out feed rate and the time from the beginning of processing.