scholarly journals Z-Map Based Cutting Force Prediction for Elliptical Ultrasonic Vibration-Assisted Milling Process

Author(s):  
Zhongqun Li ◽  
Jiandong Xiao Xiao ◽  
Xiong HAN ◽  
Weifeng ZHANG

Abstract Elliptical ultrasonic vibration-assisted milling (EUVAM) adds high-frequency vibration to conventional milling (CM) to realize high-frequency intermittent milling. It has broad application prospects in the processing of difficult-to-cut materials such as titanium alloys, superalloys and hard and brittle materials. To reveal the mechanism of the highly intermittent cutting nature in EUVAM, according to the motion relationship between cutting edge and workpiece and the Z-map model of the workpiece, a method and its algorithm for calculating undeformed cutting thickness and thus the cutting force in EUVAM are proposed. The simulation results show that EUVAM can improve the actual cutting speed when compared with CM, and the proportion of idle cutting time will directly determine the intermittent degree of the milling process. The experiment of EUVAM is performed to verify the correctness of the proposed cutting force model, and the impact of spindle speed on the cutting force in EUVAM is also analyzed.

Author(s):  
Chenjun Wu ◽  
Shijin Chen ◽  
Caiwei Xiao ◽  
Kai Cheng ◽  
Hui Ding

In this paper, a longitudinal–torsional ultrasonic vibration-assisted side milling is investigated. Different from the continuous cutting process in conventional side milling, the longitudinal–torsional ultrasonic vibration milling process is high-frequency intermittent. The intermittent cutting process is caused by the helical trajectory of the cutting edge. A mathematical model is established to simulate the trajectory and then the high-frequency intermittent cutting process is analyzed based on the model. Spindle speed, helix angle of milling tool, and ultrasonic vibration amplitudes are found to be the factors that are responsible for the ultrasonic cutting effect. When the spindle speed is 1500 r/min and the helical angle of milling tool is 30°, ultrasonic vibration milling experiments have shown that the cutting force can be reduced by 45.8% in the x direction at the most, 27.6% in the y direction, and 48% in the z direction compared to conventional milling. The experimental results also show that the decrement of the cutting force decreases along with the increasing of the cutting speed and helical angle of milling tool due to the decrease of the uncutting time. However, the increasing of the vibration amplitude can increase the decrement.


2011 ◽  
Vol 188 ◽  
pp. 404-409 ◽  
Author(s):  
Xue Yan ◽  
Hua Tao ◽  
D.H. Zhang ◽  
B.H. Wu

A developed method to predict the cutting forces in end milling of generalized corners is proposed in this paper. The cornering milling process is divided into a series of cutting segments with different cutting states. The mathematical model of the geometric relationship between cutter and the corner profile is established for each segment. Cutting forces is predicted by introducing the classical cutting force model. The computational results of cutting forces are in good agreement with experimental data.


Author(s):  
Jieqiong Lin ◽  
Chao Wang ◽  
Mingming Lu ◽  
Jiakang Zhou ◽  
Shixin Zhao ◽  
...  

The machining process of SiCp/Al composites is considerably difficult because of the addition of ceramic particles. As an effective machining method, ultrasonic vibration-assisted turning is used to process SiCp/Al composites, which can effectively reduce the cutting force, improve the surface quality, and reduce the tool wear. This study developed a cutting force prediction model for ultrasonic vibration-assisted turning of SiCp/Al composites, which comprehensively considers the instantaneous depth of cut and the instantaneous shear angle. This model divides the cutting force into the chip formation force considering the instantaneous depth of cut, the friction force considering the influence of SiC particles at tool-chip interface, the particle fracture force, and the ultrasonic impact force in the cutting depth direction. By comparing the predicted value of the main cutting force with the experimental values, the results present the same trend, which verifies the feasibility of the cutting force prediction model. In addition, the influence of vibration amplitude, depth of cut, and cutting speed on the main cutting force is analyzed. The systematic cutting experiments show that ultrasonic vibration-assisted turning can significantly reduce the cutting force and improve the machinability of SiCp/Al composites.


2011 ◽  
Vol 418-420 ◽  
pp. 840-843
Author(s):  
Qing Hua Song ◽  
Xing Ai

The efficiency of the high-speed milling process is often limited by the occurrence of chatter. In order to predict the occurrence of chatter, accurate models are necessary. With the speed increasing, gyroscopic effect plays an important pole on the system behavior, including dynamic characteristic and rotating behavior. Considering the influence of gyroscopic effect on rotating behavior, an updated model for the milling process is presented which features as model of the equivalent profile of tool. In combination with this model, a nonlinear instantaneous cutting force model is proposed. The use of this updated equivalent profile of tool results in significant differences in the static uncut thickness compared to the traditional model.


Author(s):  
Wanfei Ren ◽  
Jinkai Xu ◽  
Jieqiong Lin ◽  
Zhanjiang Yu ◽  
Peng Yu ◽  
...  

This paper aims to study the surface homogenization and integrity of Ti-6Al-4V alloy by longitudinal-torsional coupled ultrasonic vibration assisted ball-end milling. A method of continuous processing between the flat surface and freeform surface connection is proposed by using ultrasonic vibration assisted ball-end precision milling, during this process, it is not necessary to exchange the cutting tool. The way has been explored for changing the homogenization of surface on Ti-6Al-4V by ultrasonic vibration-assisted milling (UVAM). Cutting experiments employing three parameters, cutting speed, feed rate and depth of cut and two types of machining forms using ball-end milling with UVAM and conventional milling (CM) respectively. The high frequency cutting force, finished surface roughness, topography and residual stresses on the surface and tool wear have been measured by advanced instruments. Particularly, adopting the high frequency cutting force measurement system, it is concluded cutting force in ball-end milling decreased significantly using UVAM as against CM. Moreover, the surface roughness by UVAM with ball-end milling is much better than the CM at a high cutting speed. However, an opposite trend is observed at a low cutting speed. Especially, there is a steep decrease from Ra 0.828 μm average value at 4000 rpm to Ra 0.129 μm average value at 5000 rpm. At the same time, the homogenization of surface roughness and residual stresses decrease significantly in UVAM as compared to which in CM when taking the transversal-longitudinal ratio into consideration. Cutting experiments and measuring results are demonstrated the validity and feasibility of UVAM with ball-end milling, and this method enjoys significant advantages compared to CM process.


2010 ◽  
Vol 4 (3) ◽  
pp. 221-228 ◽  
Author(s):  
Takashi Matsumura ◽  
◽  
Takahiro Shirakashi ◽  
Eiji Usui

An adaptive force model is presented to predict the cutting force and the chip flow direction in milling. The chip flow model in the milling process is made by piling up the orthogonal cuttings in the planes containing the cutting velocities and the chip flow velocities. The chip flow direction is determined to minimize the cutting energy. The cutting force is predicted using the determined chip flow model. The force model requires the orthogonal cutting data, which associate the orthogonal cutting models with the cutting parameters. Basically, the required data for simulation can be measured in the orthogonal cutting tests. However, it is difficult to perform the cutting tests with specialized setups in the machine shops. The paper presents the adaptive model to accumulate and update the orthogonal cutting data with referring the measured cutting forces in milling. The orthogonal cutting data are identified to minimize the error between the predicted and the measured cutting forces. Then, the cutting forces can be predicted well in many cutting operations using the identified orthogonal cutting data. The adaptive is effective not only in extending the database but also in improving the quality of the database for the accurate predictions.


2011 ◽  
Vol 148-149 ◽  
pp. 374-379
Author(s):  
Long Bai ◽  
Tao Wang ◽  
Xi Bin Wang ◽  
Jian Jun Chen

The present paper demonstrates a study of the impact of cutting condition on turning high strength steel 34CrNiMo6. Based on Taguchi method, a plan of experiments was performed with ceramic cutting insert. The first and second cutting force equations are developed through the response surface methodology (RSM) to investigate the effect of input cutting parameters (cutting speed, feed rate and depth) on cutting force. In term of input parameters, the cutting force contours are showed and the analysis of the predicted models is performed with aid of the statistical software package. In addition, the separate influence of individual cutting parameter and the interaction between these factors are also discussed in this study. In general, the results obtained from the mathematical model agree well with the experimental data.


Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 326
Author(s):  
Lan Zhang ◽  
Xianbin Sha ◽  
Ming Liu ◽  
Liquan Wang ◽  
Yongyin Pang

In the field of underwater emergency maintenance, submarine pipeline cutting is generally performed by a diamond wire saw. The process, in essence, involves diamond grits distributed on the surface of the beads cutting X56 pipeline steel bit by bit at high speed. To find the effect of the different parameters (cutting speed, coefficient of friction and depth of cut) on cutting force, the finite element (FEA) method and response surface method (RSM) were adopted to obtain cutting force prediction models. The former was based on 64 simulations; the latter was designed according to DoE (Design of Experiments). Confirmation experiments were executed to validate the regression models. The results indicate that most of the prediction errors were within 10%, which were acceptable in engineering. Based on variance analyses of the RSM models, it could be concluded that the depth of the cut played the most important role in determining the cutting force and coefficient the of friction was less influential. Despite making little direct contribution to the cutting force, the cutting speed is not supposed to be high for reducing the coefficient of friction. The cutting force models are instructive in manufacturing the diamond beads by determining the protrusion height of the diamond grits and the future planning of the cutting parameters.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 460
Author(s):  
Canbin Zhang ◽  
Chifai Cheung ◽  
Benjamin Bulla ◽  
Chenyang Zhao

Ultrasonic vibration-assisted cutting (UVAC) has been regarded as a promising technology to machine difficult-to-machine materials such as tungsten carbide, optical glass, and hardened steel in order to achieve superfinished surfaces. To increase vibration stability to achieve optical surface quality of a workpiece, a high-frequency ultrasonic vibration-assisted cutting system with a vibration frequency of about 104 kHz is used to machine spherical optical steel moulds. A series of experiments are conducted to investigate the effect of machining parameters on the surface roughness of the workpiece including nominal cutting speed, feed rate, tool nose radius, vibration amplitude, and cutting geometry. This research takes into account the effects of the constantly changing contact point on the tool edge with the workpiece induced by the cutting geometry when machining a spherical steel mould. The surface morphology and surface roughness at different regions on the machined mould, with slope degrees (SDs) of 0°, 5°, 10°, and 15°, were measured and analysed. The experimental results show that the arithmetic roughness Sa of the workpiece increases gradually with increasing slope degree. By using optimised cutting parameters, a constant surface roughness Sa of 3 nm to 4 nm at different slope degrees was achieved by the applied high-frequency UVAC technique. This study provides guidance for ultra-precision machining of steel moulds with great variation in slope degree in the pursuit of optical quality on the whole surface.


2014 ◽  
Vol 1017 ◽  
pp. 747-752
Author(s):  
Hiromi Isobe ◽  
Keisuke Hara

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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