Fracture of Carbide Tools in Intermittent Cutting

1983 ◽  
pp. 735-755
Author(s):  
H. Chandrasekaran
Keyword(s):  
Intermittent Cutting

Testing Aluminium Oxide based Ceramics at Irregular Interrupted Cut

2013 ◽  
Vol 10 (2) ◽  
pp. 26-28
Author(s):  
Ladislav Kyncl ◽  
Robert Cep ◽  
Pavel Novacek ◽  
Jiri Schreier
Keyword(s):  
Aluminium Oxide ◽  
Cutting Effect ◽  
Intermittent Cutting

Abstract This article discusses the test removable ceramic plates during machining with interrupted cut. Tests were performed on a lathe, which was clamped preparation which simulated us the interrupted cut. By changing the number plates mounted in a preparation it was a regular or irregular cut. When with four plates it was regular interrupted cut, the remaining three variants were already irregular cut. It was examined whether it will have the irregular intermittent cutting effect on the insert and possibly how it will change life of inserts during irregular interrupted cut.

Effects of Cooling Conditions on Thermal Crack Initiation of Brittle Cutting Tools during Intermittent Cutting

2015 ◽  
Vol 656-657 ◽  
pp. 237-242
Author(s):  
Kenji Yamaguchi ◽  
Tsuyoshi Fujita ◽  
Yasuo Kondo ◽  
Satoshi Sakamoto ◽  
Mitsugu Yamaguchi ◽  
...  
Keyword(s):  
Crack Initiation ◽  
Thermal Shock ◽  
High Speed ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Cutting Condition ◽  
Thermal Crack ◽  
Cooling Conditions ◽  
Cutting Operation ◽  
Intermittent Cutting

It is well known that a series of cracks running perpendicular to the cutting edge are sometimes formed on the rake face of brittle cutting tools during intermittent cutting. The cutting tool is exposed to elevated temperatures during the periods of cutting and is cooled quickly during noncutting times. It has been suggested that repeated thermal shocks to the tool during intermittent cutting generate thermal fatigue and result in the observed thermal cracks. Recently, a high speed machining technique has attracted attention. The tool temperature during the period of cutting corresponds to the cutting speed. In addition, the cooling and lubricating conditions affect the tool temperature during noncutting times. The thermal shock applied to the tool increases with increasing cutting speed and cooling conditions. Therefore, to achieve high-speed cutting, the evaluation of the thermal shock and thermal crack resistance of the cutting tool is important. In this study, as a basis for improving the thermal shock resistance of brittle cutting tools during high-speed intermittent cutting from the viewpoint of cutting conditions, we focused on the cooling conditions of the cutting operation. An experimental study was conducted to examine the effects of noncutting time on thermal crack initiation. Thermal crack initiation was found to be restrained by reducing the noncutting time. In the turning experiments, when the noncutting time was less than 10 ms, thermal crack initiation was remarkably decreased even for a cutting speed of 500 m/min. In the milling operation, the number of cutting cycles before thermal crack initiation decreased with increasing cutting speed under conditions where the cutting speed was less than 500 m/min. However, when the cutting speed was greater than 600 m/min, thermal crack initiation was restrained. We applied the minimal quantity lubrication (MQL) coolant supply to the intermittent cutting operation. The experimental results showed that the MQL diminished tool wear compared with that under the dry cutting condition and inhibited thermal crack initiation compared with that under the wet cutting condition.

High-Speed Capturing of Stress Distribution of Workpiece under Ultrasonically Assisted Cutting Condition

2014 ◽  
Vol 1017 ◽  
pp. 747-752
Author(s):  
Hiromi Isobe ◽  
Keisuke Hara
Keyword(s):  
Stress Distribution ◽  
Cutting Force ◽  
High Speed ◽  
Cutting Tool ◽  
Light Emission ◽  
Cutting Speed ◽  
Cutting Condition ◽  
Photoelastic Method ◽  
Intermittent Cutting ◽  
Ultrasonic Vibration Cutting

This paper reports the stress distribution inside the workpiece under ultrasonic vibration cutting (UVC) condition. Many researchers have reported the improvement of tool wear, burr generation and surface integrity by reduction of time-averaged cutting force under UVC condition. However general dynamometers have an insufficient frequency band to observe the processing phenomena caused by UVC. In this paper, stress distribution inside the workpiece during UVC was observed by combining the flash light emission synchronized with ultrasonically vibrating cutting tool and the photoelastic method. Instantaneous stress distribution during UVC condition was observed. Because UVC induced an intermittent cutting condition, the stress distribution changed periodically and disappeared when the tool leaved from the workpiece. It was found that instantaneous maximum cutting force during UVC condition was smaller than quasi-static cutting force during conventional cutting when the cutting speed was less than 500 mm/min.

Modeling of residual stresses by correlating surface topography in machining of AISI 52100 steel

2021 ◽  
pp. 1-26
Author(s):  
Chao Liu ◽  
Yan He ◽  
Yufeng Li ◽  
Yulin Wang ◽  
Shilong Wang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Cutting Force ◽  
Surface Topography ◽  
Analytical Model ◽  
Analytical Models ◽  
Workpiece Surface ◽  
Dynamic Cutting Force ◽  
Intermittent Cutting ◽  
Effect Of Surface

Abstract The residual stresses could affect the ability of components to bear loading conditions and also the performance. The researchers considered workpiece surface as a plane and ignored the effect of surface topography induced by the intermittent cutting process when modeling residual stresses. The aim of this research develops an analytical model to predict workpiece residual stresses during intermittent machining by correlating the effect of surface topography. The relative motions of tool and workpiece are analyzed for modeling thermal-mechanical and surface topography. The influence of dynamic cutting force and thermal on different positions of surface topography is also considered in analytical model. Then the residual stresses model with the surface topography effect can be developed in intermittent cutting. The analytical models of dynamic cutting force, surface topography and residual stresses are verified by the experiments. The variation trend of evaluated values of the residual stress of workpiece is basically consistent with that of measured values. The compressive residual stress of workpiece surface in highest point of the surface topography are higher than that in the lowest point.

An Investigation of the Predicting Capabilities of a Variable Flow Stress Machining Theory

2001 ◽  
Author(s):  
P. Mathew
Keyword(s):  
Flow Stress ◽  
Material Flow ◽  
Three Dimensional ◽  
Experimental Results ◽  
Two Dimensional ◽  
Variable Flow ◽  
Comparative Results ◽  
Intermittent Cutting ◽  
Theoretical Results ◽  
Modelling Approach

Abstract The Oxley Machining Theory, which has been developed over the last 40 years, is presented in this paper. The capability of the model is described with its initial two-dimensional machining approach followed by the extension to the generalised model for three-dimensional machining. The theoretical results from the model are compared with the experimental results to determine the model capability. A brief description of the work associated with the effect of strain hardening at the interface is presented and comparative results are shown. A further extension of the model to intermittent cutting process of reaming is also presented and a comparison with the experimental results indicates the model developed is quite capable of predicting cutting forces for reaming. In explaining the results obtain, the assumptions made are explained and the inputs required. The limitations of the modelling approach are presented. It is pointed out that the Oxley model is a versatile model as long as proper description of the material flow stress properties is presented.

Analytical Modeling of Machining Forces and Friction Characteristics in Ultrasonic Assisted Turning Process

2021 ◽  
pp. 1-13
Author(s):  
Jay Airao ◽  
Chandrakant Kumar Nirala
Keyword(s):  
Analytical Model ◽  
Work Piece ◽  
Contact Ratio ◽  
Friction Characteristics ◽  
Machining Forces ◽  
Ultrasonic Assisted ◽  
Predicted Model ◽  
Ss 304 ◽  
Intermittent Cutting ◽  
Conventional Machining

Abstract Intermittent cutting characteristics of Ultrasonic assisted turning (UAT), Compared to conventional turning (CT), has shown a significant enhancement in the machinability of hard-to-cut materials. The enhancement in machinability is associated with machining forces and friction characteristics of the process. The present article covers an analytical approach to predict the output responses such as machining forces and friction characteristics in UAT and CT processes. Specific cutting energy (SCE) for a particular work-piece material was considered to predict the output responses. The predictions were made by considering the conventional machining theories. Experiments for the UAT and the CT of SS 304 were carried out to validate the predicted model. The results from the analytical model showed that the shear angle increases and the tool-workpiece contact ratio (TWCR) decrease with an increase in amplitude and frequency of vibration. The results obtained from the analytical model were found to be in close agreement with the experimental ones, with an approximate error of 2-20%.

Analysis of characteristics of arc shape caused by intermittent cutting force and dynamic vibration in ultra-precision cutting processes

2020 ◽  
Vol 234 (14) ◽  
pp. 1742-1751
Author(s):  
Wei Wei ◽  
Jiasheng Li ◽  
Yi Chen ◽  
Xiaojin Huang
Keyword(s):  
Cutting Force ◽  
Surface Characteristics ◽  
Spindle Speed ◽  
Feed Speed ◽  
Dynamic Vibration ◽  
Tool Shape ◽  
Arc Shape ◽  
Ultra Precision ◽  
Cutting Processes ◽  
Intermittent Cutting

This article analyzes the phenomenon of “arc shape” in surface characteristics caused by dynamic vibration in ultra-precision machining. First, a surface simulation model is proposed based on the effect of the tool shape on the cutting profile. The accurate mapping relationship between spindle speed, feed speed, relative vibration, and the motion track of the tool tip to the workpiece profile is also established. Thereafter, the input frequency spectrum signature of an intermittent cutting force is found to be determined by the spindle speed and workpiece characteristics, and this is verified by experimental results. A phased, self-regulated mode of forced vibration caused by intermittent cutting force is then proposed, and the forming of the arc shape feature is explained. In addition, it is revealed that output vibration can be kept at a low level by adjusting the spectrum curve of the input signal.

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