Transformation of groove area distribution non-uniformity in partially regular microrelief of the rotational type with increasing axial pitch

Abstract

The transformation of the groove shape in a rotary-type regular micro-relief with varying degrees of groove loop overlap, simulated by an increase in the rotary tool feed rate, is considered. A search was conducted to find the optimal groove shape for partially regular micro-reliefs formed by the rotary method, subject to ensuring the optimal value of the planar heterogeneity coefficient of the groove area distribution. Graphs illustrating the planar heterogeneity of the groove area distribution were constructed for groove shapes formed at tool feed rates of 2.5, and 3.5 mm/s. It was established that as the longitudinal spindle feed rate increases, the planar heterogeneity coefficient of the groove area distribution, decreases in both the axial direction and the direction perpendicular to it. Thus, it is proven that increasing the tool feed rate at a constant rotational speed leads to an increase in the heterogeneity of the groove area distribution for a partially regular micro-relief formed by the rotary method. Optimization of the micro-relief creates a favorable profile of compressive residual stresses, preventing the propagation of microcracks. As the tool feed rate increases, the number of groove intersections decreases from 4 to 2, and the shape itself becomes elongated in the axial direction. Correspondingly, the planar heterogeneity coefficients k_gX decrease from 0.69 to 0.48, and k_gY decrease from 0.71 to 0.6. The overall relative area of the micro-relief, F_n, drops sharply from 68.48% to 45.9%, which is a critical parameter for determining the load-bearing capacity of the component surfaces.