Ultra High-Speed Cutting Experiment under the Cutting Condition that Cutting Speed Exceeds Plastic Wave Speed of Workpiece

2011 ◽  
Vol 325 ◽  
pp. 327-332 ◽  
Author(s):  
Jun Shinozuka ◽  
Masato Sando ◽  
Tasuku Horie
Keyword(s):  
Shock Wave ◽  
Shear Zone ◽  
High Speed ◽  
Cutting Speed ◽  
Experimental Result ◽  
Cutting Condition ◽  
Plastic Wave ◽  
High Speed Cutting ◽  
Ultra High Speed ◽  
Impact Cutting

Raising a cutting speed to above speed of a plastic wave of a workpiece material induces the high levels of the hydrostatic stresses in the shear zone, because a plastic wave traveling there becomes a shock wave. In order to ascertain the cutting phenomena occurring under the ultra high-speed cutting condition, the cutting experiments of a pure lead with cutting speeds of up to 140 m/s are performed with a high-speed impact cutting tester developed. The experimental result reveals that the cutting mechanism, especially chip formation, changes remarkably and the friction angle at the tool-chip interface rises in the ultra high-speed cutting. It can be explained that these phenomena arise from the plastic shock wave in the shear zone.

Ultra High Speed Turning of Inconel 718 with Sialon Ceramic Tools

2010 ◽  
Vol 126-128 ◽  
pp. 653-657 ◽  
Author(s):  
Guang Ming Zheng ◽  
Jun Zhao ◽  
Xin Yu Song ◽  
Cao Qing Yan ◽  
Yue En Li
Keyword(s):  
Wear Mechanisms ◽  
Inconel 718 ◽  
High Speed ◽  
Cutting Speed ◽  
Optical Microscope ◽  
Cutting Condition ◽  
Inconel 718 Alloy ◽  
High Speed Turning ◽  
Sialon Ceramic ◽  
Ultra High Speed

This paper explores the wear mechanisms of a Sialon ceramic tool in ultra high speed turning of Nickel-based alloy Inconel 718. Microstructures of the chips are also investigated. Stereo optical microscope and scanning electron microscope (SEM) are employed to observe worn surfaces of the tool produced by various wear mechanisms and morphological features of chips. In addition, the elemental compositions of wear products are evaluated by energy-dispersive X-ray spectroscopy (EDS). As a result of the study, wear mechanisms identified in the machining tests involve adhesive wear and abrasive wear. At the initial stage of cutting process, crater wear and flank wear are the main wear patterns. At the rapid wear stage, the SEM and EDS results showed that the adhered elements of Inconel 718 alloy on the tool rake face such as Ni, Fe and Cr accelerated the tool wear rate. Meanwhile, it was found that the chip morphology was serrated type under ultra high speed cutting condition, furthermore, the tendency of serration of the chip increased with the increase in cutting speed and feed rate.

Calculating of the Temperature Distribution of Primary Shear Zone in Orthogonal High Speed Cutting Based on the Non-Uniform Volume Moving Heat Source

2009 ◽  
Vol 626-627 ◽  
pp. 105-110 ◽  
Author(s):  
Guo He Li ◽  
Min Jie Wang
Keyword(s):  
Temperature Distribution ◽  
Heat Source ◽  
Shear Zone ◽  
High Speed ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Constitutive Relationship ◽  
Moving Heat Source ◽  
High Speed Cutting ◽  
Strain And Strain Rate

A method was presented for calculating the temperature distribution of primary shear zone in orthogonal high speed cutting based on the non-uniform volume moving heat source. The temperature distribution of primary shear zone in orthogonal high speed cutting was calculated by the dynamic plastic constitutive relationship and the distribution of strain and strain rate of primary shear zone. The results show that the temperature distribution of primary shear zone is uneven, from the original plane to the cutoff plane, the cutting temperature increases continuously. In the middle of primary shear zone, the change of cutting temperature is larger, at the position near to original plant and cutoff plane, the change of cutting temperature is smaller. The cutting temperature increases with the increase of cutting speed and cutting depth, but decreases with the increase of rake angle. The comparison with existing method shows that the method presented in this paper is not only available, but also simple, convenient and more accord with the fact of orthogonal high speed cutting.

Experiment Study of Serrated Chip and Surface Roughness of High Speed Cutting of Ti6Al4V

2014 ◽  
Vol 800-801 ◽  
pp. 571-575
Author(s):  
Guo He Li ◽  
Yu Jun Cai ◽  
Hou Jun Qi
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
Cutting Speed ◽  
Rake Angle ◽  
Adiabatic Shear ◽  
Cutting Condition ◽  
Experiment Study ◽  
Cutting Depth ◽  
Serrated Chip ◽  
High Speed Cutting

Under the condition of cutting speed 10-300m/min, rake angle -10°、0°、10°and cutting depths 0.05mm、0.1mm and 0.2mm, the experiment study of adiabatic shear serrated chip and surface roughness are carried out. The influence of cutting condition on serrated chip is analyzed through the metallographic observation of obtained chip. By the measurement of finished surface, the influenc of cutting condition and adiabatic shear on surface roughness is also investigated. The rusults show that the reason lead to serrated chip in high speed cutting of Ti6Al4V is adiabatic shear, not the periodic fracture.The adiabatic shear serrated chip is easier appear and the degree of segment is more large under the condition of higher cutting speed, larger cutting depth and smaller rake angle. The surface roughness is smaller when the cutting speed is higher, cutting depth is larger, and rake angle is smaller.

Contributions of High-Speed Cutting and High Rake Angle to the Cutting Performance of Natural Rubber

2014 ◽  
Vol 8 (4) ◽  
pp. 550-560 ◽  
Author(s):  
Naoki Takahashi ◽  
◽  
Jun Shinozuka
Keyword(s):  
Natural Rubber ◽  
Shear Zone ◽  
High Speed ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Rake Angle ◽  
Cutting Performance ◽  
Machined Surface ◽  
Shape Accuracy ◽  
High Speed Cutting

This study investigates the contributions of high-speed cutting and a high rake angle to the improvement of the cutting performance of natural rubber. Orthogonal cutting experiments were conducted at cutting speeds ranging from 1.0 m/s to 141.1 m/s. The rake angles examined were 0°, 20° and 50°. The following results were obtained from the experiments. The cutting ratio is almost 1.0 regardless of the cutting speed and rake angle. The cutting force rises rapidly as the cutting speed increases. High-speed cutting or a high rake angle eliminates tear defects on the machined surface and reduces chipping defects at the entry edge of the workpiece. An uncut portion, however, always remains at the exit edge. The cross-sectional shape of the machined surface becomes concave. Besides, the machined surface comes into broad contact with the clearance face. These degradations in the shape accuracy arise from the large elastic distortion that occurs in the shear zone. Increasing the cutting speed improves the flatness of the machined surface. Although an analysis of the cutting mechanism reveals that the apparent stiffness of the material in the shear zone is enhanced with increasing the cutting speed, a very high cutting speed worsens the shape accuracy because of the development of shock waves. Depending on the rake angle, there is a critical cutting speed that should not be exceeded to maximize the cutting performance of natural rubber.

scholarly journals Machinability of SMART Forging Process Materials in Intermittent Cutting: 2nd Report : Machinability in Normal Cutting Region and Selection of Optimum Cutting Condition

2019 ◽  
Vol 95 ◽  
pp. 01001
Author(s):  
Mitsuaki Murata ◽  
Makoto Hino ◽  
Ryoichi Kuwano ◽  
Syuhei Kurokawa
Keyword(s):  
High Speed ◽  
Combustion Engine ◽  
Hot Forging ◽  
Cutting Speed ◽  
Maximum Speed ◽  
Cutting Condition ◽  
High Speed Cutting ◽  
Cutting Experiments ◽  
Intermittent Cutting ◽  
Selection Of

Transmission used in automobiles is indispensable from the viewpoint of improvement of maximum speed, quietness and fuel consumption even if the power source of automobile is changed from internal combustion engine to electric motor in the future. We are studying a heat treatment process for imparting machinability to the forged material after hot forging used for a transmission of automobiles. In the past, the heat stored in the material after hot forging was merely released into the atmosphere. We succeeded in imparting machinability to the material by cooling while well controlling the heat stored in the forged material after hot forging. In the previous paper [1], we reported the progress of tool wear of this forged material in the high-speed cutting region with the cutting speed of 200 m/min or more in intermittent cutting. In this report, we conducted cutting experiments on the machinability of this developed forged material in the normal cutting speed region with the cutting speed less than 200 m/min. As a result, at the cutting speed V of V=157 m/min or less, it reached the conclusion that the built-up edges frequently occurred and the tool was chipped due to it. From the previous report and the results of this experiment, it was found that the cutting speed V of about V=213 m/min is optimum for cutting these forged materials with cemented carbide.

Experimental Investigation of Heat Partition Ratio for the Cutting Tool at a Cutting Speed Ranging from 38 to 6500 m/min

2016 ◽  
Vol 874 ◽  
pp. 450-456
Author(s):  
Jun Shinozuka ◽  
Daiki Kidoura
Keyword(s):  
High Speed ◽  
Cutting Tool ◽  
Cutting Speed ◽  
Partition Ratio ◽  
Depth Of Cut ◽  
High Speed Cutting ◽  
Heat Partition ◽  
Impact Cutting ◽  
Cutting Length ◽  
Cutting Experiment

This paper investigated the variation in a heat partition ratio of the cutting tool with the cutting speed ranging from 38 m/min to 6500 m/min. The orthogonal high-speed cutting experiment was performed utilizing an impact cutting tester developed. The cutting length in this study was 60 mm. The temperatures at the tool-chip interface were measured directly with three pairs of Cu/Ni micro thermocouples fabricated on the rake face. The temperature rises rapidly from the beginning of cutting, and then levels off when a cutting distance exceeds about 10 to 20 times the depth of cut. The distance depends on the cutting speed. Using the temperatures measured, a variation in the heat partition ratio with cutting time was estimated with the aid of a FEA. The heat partition ratio at the end of cutting estimated decreases approximately from 7 % to 1 % as the cutting speed increases from 38 m/min to 6500 m/min. The heat partition ratio estimated is quite higher than that calculated by employing an analysis assuming the steady state, particularly under the high speed cutting conditions.

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.

The Application of FEA in High-Speed Cutting

2011 ◽  
Vol 287-290 ◽  
pp. 104-107
Author(s):  
Lian Qing Ji ◽  
Kun Liu
Keyword(s):  
High Speed ◽  
Feeding Rate ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Material Model ◽  
Friction Model ◽  
Cutting Depth ◽  
High Speed Cutting ◽  
Key Technologies

The history and application of the FEA are briefly presented in this paper. Several key technologies such as the building of material model, the establishment of the chip - tool friction model as well as meshing are described. Taking the high-speed cutting of titanium alloy (Ti - 10V - 2Fe - 3Al) as an example , reasonable cutting tools and cutting parameters are determinted by simulating the influences of cutting speed, cutting depth and feeding rate on the cutting parameters using FEA.

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.

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