Machinability improvement in three-dimensional (3D) ultrasonic vibration assisted diamond wire sawing of SiC

Author(s):  
Lutao Yan ◽  
Xinrong Zhang ◽  
Haiyuan Li ◽  
Qinjian Zhang
2019 ◽  
Vol 72 (3) ◽  
pp. 325-331
Author(s):  
Ligang Zhao ◽  
Guofeng Xia ◽  
Yuhu Shi ◽  
Aisheng Wu

Purpose The purpose of this paper is to study the influence of the processing parameters of diamond wire sawing on surface morphology and roughness. Design/methodology/approach First, a wire saw cutting model is established to determine the positional relationship between a wire saw and the machined surface of the workpiece, and the abrasive grain cutting trajectory is generated. Through the data processing of the cutting trajectory, the simulation of the three-dimensional surface topography of the slice and the calculation of the surface roughness are realized by using the GUI programming of MATLAB. Finally, different surface roughness values are obtained by changing the machining parameters (saw wire speed and workpiece feed speed). Findings The conclusion is that the surface roughness of the slice is larger when the feed speed is higher and smaller when the linear speed is higher. Originality/value Diamond wire saw cutting is the first process of chip processing, and its efficiency and quality have an important impact on subsequent processing. This paper will focus on the influence of the sawing wire cutting processing parameters (sawing wire speed and workpiece feed speed) on the surface roughness to optimize the processing parameters and obtain smaller surface roughness values. Through MATLAB three-dimensional simulation, the surface morphology can be observed more intuitively, which provides a theoretical basis for improving the processing quality.


Author(s):  
Hagen Klippel ◽  
Stefan Süssmaier ◽  
Matthias Röthlin ◽  
Mohamadreza Afrasiabi ◽  
Uygar Pala ◽  
...  

AbstractDiamond wire sawing has been developed to reduce the cutting loss when cutting silicon wafers from ingots. The surface of silicon solar cells must be flawless in order to achieve the highest possible efficiency. However, the surface is damaged during sawing. The extent of the damage depends primarily on the material removal mode. Under certain conditions, the generally brittle material can be machined in ductile mode, whereby considerably fewer cracks occur in the surface than with brittle material removal. In the presented paper, a numerical model is developed in order to support the optimisation of the machining process regarding the transition between ductile and brittle material removal. The simulations are performed with an GPU-accelerated in-house developed code using mesh-free methods which easily handle large deformations while classic methods like FEM would require intensive remeshing. The Johnson-Cook flow stress model is implemented and used to evaluate the applicability of a model for ductile material behaviour in the transition zone between ductile and brittle removal mode. The simulation results are compared with results obtained from single grain scratch experiments using a real, non-idealised grain geometry as present in the diamond wire sawing process.


2006 ◽  
Vol 5-6 ◽  
pp. 351-358 ◽  
Author(s):  
N. Ahmed ◽  
A.V. Mitrofanov ◽  
Vladimir I. Babitsky ◽  
Vadim V. Silberschmidt

Ultrasonically assisted turning (UAT) is a novel material-processing technology, where high frequency vibration (frequency f ≈ 20kHz, amplitude a ≈15μm) is superimposed on the movement of the cutting tool. Advantages of UAT have been demonstrated for a broad spectrum of applications. Compared to conventional turning (CT), this technique allows significant improvements in processing intractable materials, such as high-strength aerospace alloys, composites and ceramics. Superimposed ultrasonic vibration yields a noticeable decrease in cutting forces, as well as a superior surface finish. A vibro-impact interaction between the tool and workpiece in UAT in the process of continuous chip formation leads to a dynamically changing stress distribution in the process zone as compared to the quasistatic one in CT. The paper presents a three-dimensional, fully thermomechanically coupled computational model of UAT incorporating a non-linear elasto-plastic material model with strain-rate sensitivity and contact interaction with friction at the chip–tool interface. 3D stress distributions in the cutting region are analysed for a representative cycle of ultrasonic vibration. The dependence of various process parameters, such as shear stresses and cutting forces on vibration frequency and amplitude is also studied.


2021 ◽  
Author(s):  
Weibo Xie ◽  
Xikui Wang ◽  
Erbo Liu ◽  
Jian Wang ◽  
Xiaobin Tang ◽  
...  

Abstract In order to study the influence of rotational speed and amplitude on the surface integrity, TC18 titanium alloy samples were milled by the process of conventional milling and longitudinal ultrasonic vibration assisted milling. The experimental data were obtained by dynamometer, thermometer, scanning electron microscope, X-ray diffractometer and three-dimensional surface topography instrument for observation and analysis. The results show that the rotational speed has a significant effect on the cutting force, cutting temperature, surface morphology and surface residual stress. Compared with ordinary milling, the surface micro-texture produced by ultrasonic vibration milling is more regular, , and with the increase of rotational speed, the influence of ultrasonic vibration on cutting force and cutting temperature decrease. There are adverse effects on surface roughness after ultrasonic vibration superposition. The influence of ultrasonic vibration on the surface residual compressive stress is also greatly reduced when the rotational speed is greater than 2400 rpm. In addition, a certain depth of plastic deformation layer can be formed under the surface of ultrasonic vibration machining, and the depth of deformation layer increases with the increase of vibration.


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