Investigation of Relationship between the Surface Roughness and Residual Stress on Pearlitic Ductile Iron Face Machined

Abstract

This study investigates the relationship between surface roughness and residual stress in face-milled pearlitic ductile iron in order to enhance the surface quality of machined parts used in manufacturing. Locally prepared pearlitic ductile iron was utilized. The cutting factors that were explicitly taken into consideration in this study were cutting speed, depth of cut, fluid flow rate and feed rate. Taguchi's design served as the foundation for the experiment, which used an orthogonal array with five levels for each factor. The experimental data were statistically analyzed using correlation and multiple regression analyses. The findings show a substantial positive relationship (R = 0.938, p ≤ 0.01) between surface roughness and surface residual stress, which is statistically significant. The depth of cut and feed rate increased the surface residual stress by 511.212 and 0.668 units respectively, while a unit increase in cutting speed and fluid flow rate (-0.100 and -453.350 units respectively) decreased it. Likewise, the surface roughness increased by 53.958 and 0.063 units, respectively, with an increase in the depth of cut and feed rate. However, a unit increase in cutting speed and fluid flow rate resulted in a reduction in surface roughness (-0.003 and -21.132 units, respectively). It can be deduced from the multiple regression analysis that surface residual stress and surface roughness are associated with all cutting factors. These results can be used as a guide to improve the surface integrity of machined items. Thus, the study provided important information on the best cutting parameters for producing a significantly good surface finish during face milling operations in manufacturing industries.