Mechanical Characteristics Generation in the Workpiece Subsurface Layers through Cutting

Abstract

The cutting process generates specific mechanical characteristics in the subsurface layers of the shaped parts. These characteristics have a decisive influence on the working properties and product durability of these parts. The orthogonal cutting process of structural heat-treated steel’s effect on the mechanical properties of the machined subsurface layers was evaluated by instrumented the nanoindentation method and sclerometry (scratch) method. As a result of this study, the relationship between the specific work in the tertiary cutting zone and the total deformation work during indenter penetration during the instrumented nanoindentation was established. The dependence of the indenter penetration depth during sclerometry of the machined subsurface layers of the workpiece was also studied. The orthogonal cutting process was carried out at different cutting speeds and tool rake angles. The cutting speed increase and the increase in the tool rake angle cause an increase in the indenter penetration work during the instrumented nanoindentation and an increase in the maximum indenter penetration depth during sclerometry. Simultaneously, the measured microhardness of the machined surfaces decreases with both an increase in cutting speed and an increase in the tool rake angle.

Generation of Mechanical Characteristics in Workpiece Subsurface Layers through Milling

“…Taking into account this interest, a study of the influence of the milling process with end milling cutters on the formation of physical and mechanical characteristics of the workpiece subsurface layers was carried out, and titanium alloy was used as the machined material. This study is a continuation and methodological development of a previously published paper [17]. In the previous study [17], a coincidence of cutting power and cutting work with the mechanical characteristics of subsurface layers formed during the orthogonal cutting of structural steel was established.…”

“…This study is a continuation and methodological development of a previously published paper [17]. In the previous study [17], a coincidence of cutting power and cutting work with the mechanical characteristics of subsurface layers formed during the orthogonal cutting of structural steel was established. The cutting power and cutting work in the orthogonal cutting process were determined for different cutting speeds and tool rake angles.…”

“…The next step is devoted to measuring the mechanical characteristics of the milled subsurface layers of the workpiece. These characteristics include the microhardness of the machined layers, the indenter penetration total work, and the maximum depth of indenter penetration [17,55]. The first two mechanical characteristics are measured using instrumented nanoindentation, and the last characteristic is determined by the sclerometry of the workpiece machined surfaces.…”

“…The determination of the material mechanical properties using the sclerometry method was also used somewhat later to investigate the microstructure and hardening of materials by estimating the indenter penetration depth into the test material (see, e.g., [77][78][79]). Recently, the tool indentation method and the sclerometry method have been used not only to determine the above-mentioned individual mechanical characteristics of the parts' subsurface layers subjected to various machining processes but also to evaluate the integral (energy) mechanical characteristics [17,80]. In this regard, it is necessary to note the study of Bezyazychnyy et al [81], devoted to the establishment of the relationship between cutting modes and physical and mechanical characteristics of the machined material, and the specific accumulated strain energy of this material along the workpiece depth.…”

“…These circumstances cause significant difficulties both in evaluating the above mechanical properties and in establishing their relationship with the cutting process conditions. Significant support in the evaluation of mechanical characteristics is provided by micro-and nanometer methods, in particular, instrumental nanoindentation [13,14] and the sclerometry (scratching) of surfaces [15,16], ensuring the determination of integral mechanical characteristics, which are quite closely related to the conditions of their generation, in this case, the cutting processes [17].…”