scholarly journals Experimental evaluation of the influence of tool wear on the temperature in the cutting zone during the turning of metals

2018 ◽  
Vol 226 ◽  
pp. 02011 ◽  
Author(s):  
Viktor P. Lapshin ◽  
Tatiana S. Babenko ◽  
Valentin S. Minakov ◽  
Sergey I. Kambulov

The work is devoted to the questions of experimental estimation of the influence of the degree of the tool wear, during turning of metals in metal-cutting machines, on the level of thermal energy in the contact area of the tool with the workpiece. In the work, the experimental method revealed that with the increasing of the tool wear along the back face, the power of the released thermal energy in the contact zone of the tool and the machined part increases. This is associated with an increase in the power of irreversible pre-formations in the contact area of the tool with the workpiece, the result of which is the growth of energy consumption and the growth of conversion of this energy into thermal energy in the contact zone. The main conclusion on the work can be a conclusion about the repetition of the appearance of the dependence of the level of thermal energy in the cutting zone on time, the graph of the dependence of the degree of deterioration of the instrument on time. Proceeding from this, we can talk about the possibility of linear interpolation of the heat level from the degree of wear during the synthesis of mathematical models of the processes accompanying the cutting of metals in metal cutting machines. From the point of view of a possible explanation of this connection, it can be that with the increase of the tool wear, the capacity of irreversible transformations in the workpiece and in the tool itself grows, and the result of the growth of this capacity is the increase in the power of the heat released during processing.


Mechanik ◽  
2019 ◽  
Vol 92 (4) ◽  
pp. 242-248
Author(s):  
Wit Grzesik ◽  
Joel Rech

This paper presents a range of variable machining factors which influence substantially friction directly or by the tool wear developed in the cutting zone. The group of direct factors include the workpiece and cutting tool materials coupled, the cutting/sliding velocity, cooling media supplied to the tool-chip contact zone, modification of the tool contact faces by micro-texturing. Special attention was paid to the tool wear evolution and its pronounced effect on changes of the contact conditions.



Author(s):  
V.L. Zakovorotny ◽  
V.E. Gvindzhiliya

High precision metal-cutting machines ensure that the programmed machine actuator trajectories correspond to the real ones. For lathes these are the trajectories of the longitudinal and transverse calipers of the system, as well as the spindle. The purpose of processing is to produce parts of a given quality while minimizing the manufacturing costs. The condition of the dynamic cutting system, determined by the trajectories of forces and deformations, affects the quality indicators of parts and the cutting efficiency, which depends on the intensity of tool wear. The properties of the system change depending on the phase trajectory of the power of irreversible transformations of the energy supplied to the cutting zone by the work performed. Their changes related with the evolution of the parameters of the dynamic link formed by cutting are manifested in the development of tool wear and changes in the quality of the part. Thus, the power of irreversible energy transformations is one of the internal factors causing changes in the output characteristics of processing and the state of the process. In this regard, when processing on machine tools, there is a problem of synergistic coordination of external control (for example, the CNC program) with internal one, the source of which is the irreversible transformation of the energy supplied to the cutting zone. The article considers the problem of synergetic coordination of external and internal controls during cutting process, the solution of which will allow increasing the efficiency of processing on CNC machines. A mathematical model of a controlled dynamic cutting system and control algorithms are proposed to improve the efficiency of processing parts of a given quality while minimizing the intensity of tool wear. Testing of the developed algorithms has shown that their use reduces the cost of manufacturing parts by 1.2.



Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 108
Author(s):  
Mustafa Kuntoğlu ◽  
Abdullah Aslan ◽  
Danil Yurievich Pimenov ◽  
Üsame Ali Usca ◽  
Emin Salur ◽  
...  

The complex structure of turning aggravates obtaining the desired results in terms of tool wear and surface roughness. The existence of high temperature and pressure make difficult to reach and observe the cutting area. In-direct tool condition, monitoring systems provide tracking the condition of cutting tool via several released or converted energy types, namely, heat, acoustic emission, vibration, cutting forces and motor current. Tool wear inevitably progresses during metal cutting and has a relationship with these energy types. Indirect tool condition monitoring systems use sensors situated around the cutting area to state the wear condition of the cutting tool without intervention to cutting zone. In this study, sensors mostly used in indirect tool condition monitoring systems and their correlations between tool wear are reviewed to summarize the literature survey in this field for the last two decades. The reviews about tool condition monitoring systems in turning are very limited, and relationship between measured variables such as tool wear and vibration require a detailed analysis. In this work, the main aim is to discuss the effect of sensorial data on tool wear by considering previous published papers. As a computer aided electronic and mechanical support system, tool condition monitoring paves the way for machining industry and the future and development of Industry 4.0.



Mechanik ◽  
2019 ◽  
Vol 92 (2) ◽  
pp. 85-89
Author(s):  
Wit Grzesik ◽  
Joel Rech

This paper presents different constructions of tribometers for determination of friction and tool wear developed in the cutting zone between the cutting tool and the workpiece materials. They are classified as the closed and open tribotesters. Relevant measuring techniques of various process outputs such as cutting forces, tool wear, cutting temperature and heat flux entering the contact surface of the rubbing element are outlined. Some limitations and practical applications are highlighted.





Author(s):  
Andres F. Clarens ◽  
Ye-Eun Park ◽  
Jacob Temme ◽  
Kim Hayes ◽  
Fu Zhao ◽  
...  

Carbon Dioxide is an industrial byproduct that has been proposed as an alternative metalworking fluid (MWF) carrier with lower environmental impacts and better cooling potential than existing MWFs. This paper investigates the heat removal and tool life effects of rapidly expanding supercritical CO2 (scCO2)-based MWFs relative to MWFs delivered as a flood of semi-synthetic emulsion or as minimum quantity lubrication (MQL) sprays. When cutting both compacted graphite iron (CGI) and titanium, tool wear was most effectively controlled using the scCO2-based MWF compared with the other MWFs. Analysis in this paper suggests that the performance benefit imparted by rapidly expanding scCO2 appears to be related to both the cooling potential and penetration of the sprays into the cutting zone. High-pressure gas sprays have lower viscosity and higher velocity than conventional MWFs. An experiment in which the spray direction was varied clearly demonstrated the importance of spray penetration in tool wear suppression. The type of gas spray is also a significant factor in tool wear suppression. For instance, a spray of N2 delivered under similar conditions to CO2 effectively reduced tool wear relative to water based fluids, but not as much as CO2. This result is particularly relevant for MQL sprays which are shown to not cool nearly as effectively as scCO2 MWFs. These results inform development of scCO2-based MWFs in other machining operations, and provide insight into the optimization of scCO2 MWF delivery.



2011 ◽  
Vol 317-319 ◽  
pp. 556-559
Author(s):  
Yue Zhang ◽  
Tong Jiang ◽  
Li Han ◽  
Qi Dong Li ◽  
Tai Li Sun ◽  
...  

Green cutting is one of the developing tends in the industry field. Water vapor can be introduced in metal cutting as coolant and lubricant due to its pollution-free, generating easily and unneeded disposal. Therefore, a special generating system is developed to produce suitable water vapor, and a simulation to the velocity of water vapor jet flow is presented. Then tool wear was investigated and a new capillary model is proposed, based on the experimental results. According to the boundary-layer theory, the kinetics equations of flow were solute. The velocity and flux of molecule are presented. In the capillary, the adsorption of tool-chip interface results in boundary lubricating film; the conical shape of capillary limits the depth of coolant and lubricant penetrating; and the negative press is the motility for coolant and lubricant penetrating. The study results show water vapor can decrease tool wear about 10% times and 20% comparing to cutting fluids and dry cutting, and water vapor could be a potential solution of green cutting.





2021 ◽  
Author(s):  
Maël Jeulin ◽  
Olivier Cahuc ◽  
Philippe Darnis ◽  
Raynald Laheurte

Abstract Most of the cutting models developed in the literature attest only to the presence of cutting forces in the balance of mechanical actions resulting from cutting. However, several studies have highlighted the presence of cutting moments during machining, and particularly 3D cutting in milling. The objective of this paper is to characterise phenomena associated with cutting moments by performing experimental mechanistic modelling in 3D cutting. For this purpose, several modelling factors will be investigated, such as the 3D cutting reference frame, the undeformed chip section, the cutting parameters, the cutting zone, etc. The predictive model of this study proves to be relatively efficient for an experimental model and allows a global prediction of cutting moments in milling. Furthermore, beyond the aspect of stress fields in the workpiece caused by cutting moments, this paper gives perspectives from an energetic point of view for which the share of moments in the energy balance could be substantial for monobloc tools.



1999 ◽  
Author(s):  
Fuqian Yang ◽  
J. C. M. Li ◽  
Imin Kao

Abstract The deformation of the wire in the wiresaw slicing process was studied by considering directly the mechanical interaction between the wire and the ingot. The wire tension on the upstream is larger than on the downstream due to the friction force between the wire and the ingot. The tension difference across the cutting zone increases with friction and the span of the contact zone. The pressure in the contact zone increases from the entrance to the exit if the wire bending stiffness is ignored. The finite element results show that the wire bending stiffness plays an important role in the wire deformation. Higher wire bending stiffness (larger wire size) generates higher force acting onto the ingot for the same amount of wire deformation, which will leads to higher material removal rate and kerf loss. While larger wire span will reduce the force acting onto the ingot for a given ingot displacement in the direction perpendicular to the wire.



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