Influence of Cutting Dynamic on the Selection of the Technological Regimes to Ensure Minimal Wear of Cutting Tools

Abstract

Introduction. The intensity of tool wear, as an increment of wear to the cutting path, characterizes one of the important processing indicators. It is used in the development of algorithms for controlling the cutting process, including the calculation of trajectories in CNC machines. As the cutting speed increases, there is a value at which the wear rate is minimal. It corresponds to the optimal value of heat production in the cutting zone, that is, the power of irreversible transformations of the energy supplied to cutting. Heat production depends on the dynamic system parameters that change along the tool path. In this regard, at the initial stage and during processing, it is necessary to coordinate the control with the properties of the dynamic cutting system. Subject. The paper offers a study and analysis of the relationship between the tool wear rate and the dynamic properties of the cutting process, and on this basis, the definition of technological modes in which the wear rate is minimal. The purpose of this work is to study the dependence of the tool wear rate on the initial and changing dynamic properties of processing along the path, and to create on this basis methods for matching technological modes with the current cutting dynamics to reduce the wear rate. Method and methodology of the work. In this paper, experimental and analytical methods are used to study the evolutionary changes in the properties of the system in relation to the development of tool wear. The developed mathematical models of the cutting system are presented, which differ from the known ones in that the power of irreversible energy transformations of the mechanical system in the interface of the back faces of the tool with the workpiece is additionally modeled. The dependence of the wear rate on the power of irreversible transformations, that is, on a given time interval in the increment of wear, is given. This takes into account the dependence of wear on the dynamic properties of the cutting system, including during its evolution. Results and discussions. It is shown that the properties of evolution are sensitive to small variations in the parameters of the dynamical system. These variations make significant changes in the wear rate. The paper reveals the dependence of wear on the properties of a dynamic system, that is, on its parameters, technological modes, beats, and other perturbations. Conclusions. The disclosure of the dependence of wear resistance on the dynamic properties of the cutting process characterizes new ideas about the factors that affect wear resistance.

Process control synergetics for metal-cutting machines

“…Therefore, even their small variations can correspond to different diagrams of wear and changes in the geometric characteristics of the surface formed by cutting. As our studies show, all evolutionary diagrams are characterized by the development of chaotic dynamics, so there is a limit cutting path after which machining is impossible [35], [36]. Consequently, all the output characteristics of the process, including the geometric topology and wear, evolve to their terminal state due to the energy of irreversible transformations.…”

“…In contrast to existing ideas about the existence of an optimal cutting speed, but unchanged along the trajectory, the performed research shows that it is necessary to consider the optimal trajectory along the work done by cutting, that is, along the displacement. In addition, tool wear depends on the parameters of the dynamic system and, first of all, uncontrolled vibration disturbances [36]- [37]. 4) Each type of phase space topology corresponds to its own skeleton geometric surface topology (Fig.…”

“…It is also shown that the output processing characteristics depend on the state of the dynamic system (DS) [22]- [28]. It is noted that the cutting DS has the property of evolutionary changes that depend on the power trajectory of irreversible energy transformations in perfect operation [28]- [36]. The next step aimed at improving the processing efficiency is the synergistic alignment of the CNC-program with the cutting dynamic system.…”

Self-organization and evolution in dynamic friction systems

“…Presented in the article materials allow explaining the experimental investigations carried out during the last thirty years in the direction of evolution of the dynamic friction system. They are described in detail in monographs [10], [14], [36], [38] and articles [15], [22], [29], [30]. Let us briefly consider the results of the experimental study of the vibration characteristics of contacting pairs during the development of their wear.…”

“…At the same time, it is shown that vibrations affect the wear rate of the contacted pairs [29]- [31]. It was the change in the vibration properties of the friction unit depending on the state of the tribo-medium that led to the development of the direction in tribo-technology, which con-sists in the creation of systems for vibration diagnostics of friction processes [30]- [33].…”