OBRABOTKAMETALLOV Vol. 24 No. 3 2022 TECHNOLOGY Ta b l e 2 Experimental matrix and results Expt. No. FN (N) T (oC) v (m/s) Weight (gm) Weight loss (gm) Volume loss (mm3) Specifi c wear rate (× 10–5) (mm3/Nm) Before test After test 1 50 70 7 5.191 5.185 0.006 2.65 1.06 2 100 100 5 5.223 5.207 0.016 7.75 1.55 3 50 130 7 5.251 5.244 0.007 3.15 1.26 4 150 130 3 5.196 5.168 0.028 13.275 1.77 5 100 50 5 5.134 5.122 0.012 5.9 1.18 6 180 100 5 5.061 5.017 0.044 20.97 2.33 7 150 130 7 5.172 5.130 0.042 19.875 2.65 8 100 100 2 5.211 5.200 0.011 5.2 1.04 9 20 100 5 5.183 5.181 0.002 0.77 0.77 10 150 70 7 5.214 5.181 0.033 15.675 2.09 11 100 100 8 5.252 5.232 0.020 9.4 1.88 12 150 70 3 5.211 5.185 0.026 12.525 1.67 13 100 150 5 5.133 5.114 0.019 9.05 1.81 14 50 130 3 5.183 5.178 0.005 2.35 0.94 15 50 70 3 5.221 5.217 0.004 1.725 0.69 useful to understand the parametric impact on wear. In the equation k, a, b, and c are constants that are obtained by developing polynomial regression model based on the experimental data. Specific wear rate ( ) . a b c s N W k F T v (3) A DataFit software was used to obtain the correlation between wear, normal load, temperature, and sliding velocity as expressed in Eq. 4. The correlation coeffi cient obtained (R2 value) is 0.9791 showed that the developed empirical expression could be effectively used to know wear rate of a PTFE composite reinforced with carbon fi ber (35 wt.%) against SS304 stainless steel in the range of parameters selected in this study. 8 0.6307 0.333 0.403 Specific wear rate ( ) 9.89 1 . 0 s N W F T v (4) From the exponents of normal load, interface temperature, and speed, it can be seen that specifi c wear rate is signifi cantly affected by normal load and after that by sliding speed, and temperature. To have a clear understanding of the effect of input parameters on specifi c wear rate 3-D graphs are plotted for specifi c wear rate using empirical Eq. (4), varying with normal load, interface temperature, and sliding speed. 3-D surface curves are plotted by varying the two process parameters at a time, keeping the other parameter constant at the mid-value of the ranges of the parameters as depicted in Table 1. The 3-D plots refl ecting the variation in the specifi c wear rate are shown in Figs. 2, a–c. Fig. 2, a depicts the variation in the wear rate with the normal load and interface temperature considering the sliding velocity of 5 m/s. Fig. 2, b shows the variation in wear rate with the sliding speed and normal load, and Fig. 12, c depicts variation with the interface temperature and sliding speed. The plots are based on varying two process parameters while maintaining a constant value of the third parameter (FN = 100N, T = 100oC, and v = 5 m/s). This study found an interaction effect of the process parameters on the PTFE composite wear rate against SS304 stainless steel.
RkJQdWJsaXNoZXIy MTk0ODM1