Tool Temperatures in Interrupted Metal Cutting

1992 ◽  
Vol 114 (2) ◽  
pp. 127-136 ◽  
Author(s):  
D. A. Stephenson ◽  
A. Ali
Keyword(s):  
Metal Cutting ◽  
Theoretical Study ◽  
Gray Cast Iron ◽  
Experimental Studies ◽  
Cutting Temperature ◽  
General Nature ◽  
Time Varying ◽  
Transient Model ◽  
Average Surface ◽  
Interrupted Cutting

This paper summarizes the results of theoretical and experimental studies of tool temperatures in interrupted cutting. In the theoretical study, the temperature in a semi-infinite rectangular corner heated by a time-varying heat flux with various spatial distributions is used to investigate the general nature of the tool temperature distribution. The results of this analysis are compared with infrared and tool-chip thermocouple cutting temperature measurements from interrupted end turning tests on 2024 aluminum and gray cast iron at speeds up to 18 m/s. The results show that temperatures are generally lower in interrupted cutting than in continuous cutting under the same conditions. Temperatures depend primarily on the length of cutting cycles and secondarily on the length of cooling intervals between cycles. For short cutting cycles the peak and average surface temperatures are relatively low, but they increase rapidly as the cutting cycle is lengthened and approach steady-state values for long cycles. Temperatures increase for very short cooling intervals, since in this case heat does not disperse between heating cycles, but for moderate and large values varying the cooling interval has little effect on temperatures. The theoretical analysis reproduces the qualitative trends but underestimates temperatures for short cutting cycles. The accuracy of the analysis could be improved by using a transient model to calculate the amount of heat entering the tool from the tool-chip contact.

scholarly journals MQL Machining with nano fluid: a review

2021 ◽  
Vol 8 ◽  
pp. 13
Author(s):  
Pralhad B. Patole ◽  
Vivek V. Kulkarni ◽  
Sudhir G. Bhatwadekar
Keyword(s):  
Surface Finish ◽  
High Speed ◽  
Metal Cutting ◽  
Experimental Studies ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Cutting Fluid ◽  
Depth Of Cut ◽  
Work Piece ◽  
Nano Fluid

In any metal cutting machining operation, the cutting fluid plays important role by cooling the cutting tool and the surface of the work piece, also chips are removed from heat affected zone. However, misuse of the cutting fluid and wrong methods of its disposal can affect human health and the environment badly. This paper presents a review of the important research papers published regarding the MQL-based application of mineral oils, vegetable oils and nano fluid-based cutting fluids for different machining processes, such as, drilling, turning, milling and grinding, etc. Most of the experimental studies have shown that application of MQL produces surface better than the flood and dry machining. In turning operation, parameters such as cutting speed, depth of cut, feed rate and tool nose radius have great impact on the surface finish. During high speed turning of steel inherently generates high cutting zone temperature. Such high temperature causes dimensional deviation and failure of cutting tools, surface and subsurface micro cracks, corrosion etc. Therefore, with proper selection of the MQL system and the cutting parameters, it is possible for MQL machining with minimum cost and less quantity of coolant to obtain better conditions, in terms of lubricity, tool life, cutting temperature and surface finish. The findings of this study show that MQL with nano fluid can substitute the flood lubrication for better surface finish.

scholarly journals An Investigation of the Work Hardening Behavior in Interrupted Cutting Inconel 718 under Cryogenic Conditions

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2202
Author(s):  
Xing Dai ◽  
Kejia Zhuang ◽  
Donglin Pu ◽  
Weiwei Zhang ◽  
Han Ding
Keyword(s):  
Work Hardening ◽  
Inconel 718 ◽  
Metal Cutting ◽  
Surface Deformation ◽  
Cutting Temperature ◽  
Service Performance ◽  
Machined Surface ◽  
Interrupted Cutting ◽  
Cutting Processes ◽  
The Given

The severe work hardening phenomenon generated in the machining of Inconel 718 is harmful to continue cutting processes, while being good for the component’s service performance. This paper investigates the performance of cryogenic assisted machining used in the cutting processes, which can reduce the waste of fluids. The influence of dry and cryogenic machining conditions with different cutting speeds on the work hardening layer is investigated based on the interrupted cutting of Inconel 718. Cutting temperature distribution obtained from simulations under different conditions is used to discuss the potential mechanism of work hardening. Then, the depth of work hardening and degree of work hardening (DWH) are investigated to analyze the surface deformation behavior, which strengthens the machined surface during metal cutting processes. From the cutting experiments, the depth of the work hardening layer can reach more than 60 μm under the given cutting conditions. In addition, a deeper zone can be obtained by the cooling of liquid nitrogen, which may potentially enhance the wear performance of the component. The results obtained from this work can be utilized to effectively control the work hardening layer beneath the surface, which can be applied to improve the service performance.

Assessment of Steady-State Metal Cutting Temperature Models Based on Simultaneous Infrared and Thermocouple Data

1991 ◽  
Vol 113 (2) ◽  
pp. 121-128 ◽  
Author(s):  
D. A. Stephenson
Keyword(s):  
Cast Iron ◽  
Steady State ◽  
Inverse Method ◽  
Metal Cutting ◽  
Gray Cast Iron ◽  
Three Dimensional ◽  
Cutting Temperature ◽  
Infrared Measurements ◽  
Thermocouple Method ◽  
Thermocouple Temperature

Several models for metal cutting temperatures which could be applied in simulation programs have been reported in the literature. Since the temperature predicted by the models are difficult to measure, however, there is not sufficient experimental data to determine which available model is most accurate and whether further theoretical refinement is needed. In this paper calculations from four steady-state cutting temperature models are compared with simultaneous infrared and tool-chip thermocouple temperature measurements from end turning tests on 1018 steel, 2024 aluminum, free machining brass, and gray cast iron tubes. Deformation zone temperatures calculated using the models are compared to source temperatures determined from infrared measurements using a new inverse method. Calculated tool-chip contact temperatures are compared to rake face temperatures measured by the widely used tool-work thermocouple method. The data indicates most models, though quantitatively accurate, overestimate cutting temperatures. Models based on Jaeger’s friction slider solution which include workpiece thermal property variations, however, generally give results accurate to within the reliability of experimentai methods for the materials tested. Loewen and Shaw’s model, recently generalized to three-dimensional cutting by Venuvinod and Lau, seems most accurate over a broad range of workpiece and cutting conditions. No model accurately predicts tool-chip temperatures for cast iron or 2024 aluminum, indicating that further theoretical refinement for discontinuous chip formation is needed.

THEORETICAL STUDY OF NOISE GENERATION DURING DRILLING OF WOOD WORKPIECES WITH REGARD TO THE DRILL FEED RATE

Akustika ◽  
2021 ◽  
pp. 183-185
Author(s):  
Dmitry Ruslyakov
Keyword(s):  
Feed Rate ◽  
Metal Cutting ◽  
Sound Pressure ◽  
Theoretical Study ◽  
Experimental Studies ◽  
Drilling Process ◽  
Noise Generation ◽  
Circular Saw ◽  
Sound Pressure Levels ◽  
Milling Machines

In contrast to metal-cutting machines, woodworking machines are characterized not only by sound pressure levels at the operators’ workplaces that exceed the sanitary standards, but also by dust concentrations that also exceed the standards. At present, a set of theoretical and experimental studies has been carried out and engineering solutions have been proposed to bring vibroacoustic characteristics and dustiness to the sanitary standards for woodworking thickness-jointing machines, band and circular saw machines, model and contour-milling machines. Studies of this kind in relation to woodworking drilling machines have not been done. It should be noted that not only the layout of woodworking drilling machines, but also the dynamics of the drilling process has significant differences from the above mentioned machines.

Experiment Study of Oil-Air Lubrication on Cooling of Turning Tools

2011 ◽  
Vol 189-193 ◽  
pp. 3187-3190 ◽  
Author(s):  
Jin Li Wang ◽  
Lin Cai ◽  
Hong Tao Zheng
Keyword(s):  
Metal Cutting ◽  
Research Work ◽  
Cutting Temperature ◽  
Cost Savings ◽  
Machining Process ◽  
Dry Cutting ◽  
Air Lubrication ◽  
Temperature Contrast ◽  
Cooling Technology ◽  
Lubrication Conditions

When lubricants are used according to special requirements, it is possible to achieve considerable cost savings. Compared to conventional coolant cooling technology used in metal cutting, oil-air lubrication increases cooling performance, avoids environmental pollution, reduces running and maintenance costs. The cutting temperature contrast experimental research was based on close to practice 45# steel in dry cutting, wet cutting and oil-air lubrication conditions. The research work concentrated on the superiority of oil-air lubrication cooling and the influence of cutting amount on temperature. The experimental results show that oil-air lubrication is more effective in reducing the cutting temperature than wet cutting or dry cutting, this paper details the cutting temperature curves at several different tests provides a basis for industrial production, improves the level of machining process and the significance was being reported.

Development of Cutting Tools With Micro-Textured Surface for High Speed Machining of Ti-6Al-4V

2021 ◽  
Author(s):  
Mitsuru Hasegawa ◽  
Tatsuya Sugihara
Keyword(s):  
Tool Life ◽  
High Speed ◽  
Metal Cutting ◽  
Failure Process ◽  
Cutting Tools ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Cutting Fluid ◽  
Textured Surface ◽  
Textured Surfaces

Abstract In cutting of Ti-6Al-4V alloy, the cutting speed is limited since a high cutting temperature leads to severe tool wear and short tool life, resulting in poor production efficiency. On the other hand, some recent literature has reported that various beneficial effects can be provided by forming micro-textures on the tool surface in the metal cutting process. In this study, in order to achieve high-performance machining of Ti-6Al-4V, we first investigated the mechanism of the tool failure process for a cemented carbide cutting tool in high-speed turning of Ti-6Al-4V. Based on the results, cutting tools with micro textured surfaces were developed under the consideration of a cutting fluid action. A series of experiments showed that the textured rake face successfully decreases the cutting temperature, resulting in a significant suppression of both crater wear and flank wear. In addition, the temperature zone where the texture tool is effective in terms of the tool life in the Ti-6Al-4V cutting was discussed.

A comprehensive experiment-based approach to generate stress field and slip lines in cutting process

2021 ◽  
pp. 1-18
Author(s):  
Zheng-Yan Yang ◽  
Xiao-Ming Zhang ◽  
Guang-Chao Nie ◽  
Dong Zhang ◽  
Han Ding
Keyword(s):  
Stress Field ◽  
Deformation Zone ◽  
Metal Cutting ◽  
Transfer Problem ◽  
Maximum Shear Stress ◽  
Cutting Temperature ◽  
Cutting Process ◽  
Slip Lines ◽  
Strain And Strain Rate ◽  
Main Deformation

Abstract This study proposes a comprehensive experiment-based method to determine stress field and slip lines in metal cutting process. The chip geometry and workpiece's strain and strain rate fields are determined using an in-situ imaging technique. The two-dimensional (2D) heat transfer problem for the steady-state cutting process is solved to derive the cutting temperature, and the flow stresses of work material in the main deformation zone are calculated based on the plasticity theory. Furthermore, the stress field is comprehensively determined to satisfy the stress equilibrium, friction law along the tool-chip interface, and traction-free boundary condition along the uncut chip surface. In addition, slip lines in the main deformation zone are derived according to the direction of maximum shear stress without the assumption of perfect rigid-plastic material. The proposed method is validated by comparing the cutting forces calculated based on the obtained stress field with the experimentally measurements.

Nonlinear Dynamics of Orthogonal Metal Cutting: Experimental Studies

1999 ◽  
Author(s):  
Chee-Hoe Foong ◽  
Marian Wiercigroch ◽  
William F. Deans
Keyword(s):  
Nonlinear Dynamics ◽  
Cast Iron ◽  
Metal Cutting ◽  
Thrust Force ◽  
Experimental Studies ◽  
Vertical Direction ◽  
Systematic Analysis ◽  
Orthogonal Metal Cutting ◽  
Time Histories ◽  
Force Components

Abstract The elimination of chatter is one of the major aims in machining to improve geometrical accuracy and surface finish. In this study, occurrence of chatter was investigated experimentally using a specially designed rig by examining time histories of the cutting and thrust force components. A broad experimental study was conducted using brass, cast iron and aluminium samples. It was found that by changing the horizontal stiffness of the rig, the thrust force variations (in the vertical direction) were completely eliminated for the cast iron samples. A systematic analysis of the chip formation for the aluminium alloy is presented.

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