Research on Surface Formation Mechanism in Elliptical Ultrasonic Assisted Grinding (EUAG) of Monocrystal Sapphire Using Structure Function Fractal Method

2015 ◽  
Author(s):  
Qiuyan Wang ◽  
Zhiqiang Liang ◽  
Xibin Wang ◽  
Wenxiang Zhao ◽  
Yongbo Wu ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Structure Function ◽  
Ground Surface ◽  
Surface Characteristics ◽  
Fractal Method ◽  
Surface Formation ◽  
Work Surface ◽  
Ultrasonic Assisted Grinding ◽  
Ultrasonic Assisted ◽  
Conventional Grinding

This study investigates surface formation characteristics in elliptical ultrasonic assisted grinding (EUAG) of monocrystal sapphire using structure function fractal method. During the EUAG process, the workpiece is imposed to ultrasonically vibrate in two directions, i.e., vertical and parallel to work-surface, by using an elliptical ultrasonic vibrator. To clarify the work-surface formation characteristics in EUAG of sapphire material, grinding experiments are carried out involving sapphire substrate. In experiments, work-surface roughness is measured, and the ground work-surface morphology is examined by scanning electron microscope (SEM) and its fractal dimension was calculated by structure function method. The fractal dimension of ground surface in EUAG is bigger than that in conventional grinding (CG), meaning that the ground surface in EUAG is more exquisite and better than that in CG. Therefore, the fractal analysis method has the potential to reveal the ground surface characteristics in EUAG of monocrystal sapphire.

Elliptical Ultrasonic Assisted Grinding (EUAG) of Monocrystal Sapphire – Surface Formation Characteristics

2010 ◽  
Vol 126-128 ◽  
pp. 367-372 ◽  
Author(s):  
Zhi Qiang Liang ◽  
Xi Bin Wang ◽  
Yong Bo Wu ◽  
Wen Xiang Zhao
Keyword(s):  
Surface Roughness ◽  
High Performance ◽  
Depth Of Cut ◽  
Surface Formation ◽  
Work Surface ◽  
Ultrasonic Assisted Grinding ◽  
Bending Mode ◽  
Ultrasonic Assisted ◽  
Conventional Grinding ◽  
Elliptical Motion

This study investigates surface formation characteristics in elliptical ultrasonic assisted grinding (EUAG) of monocrystal sapphire. During EUAG process, the workpiece is imposed to ultrasonically vibrate in two directions, i.e., vertical and parallel to work-surface, by using an elliptical ultrasonic vibrator. In our previous work, the vibrator has been produced by bonding a piezoelectric ceramic device (PZT) on a metal elastic body. When two alternating current voltages with a phase difference are applied to the PZT at the same frequency that is close to the resonant frequency of the longitudinal and bending mode of the vibrator, two dimensional ultrasonic vibrations are generated simultaneously, resulting in an elliptical motion on the end face of the vibrator. In this paper, to clarify the work-surface formation characteristics in EUAG of sapphire material, grinding experiments are carried out involving sapphire substrate. In experiments, work-surface roughness is measured, and the ground work-surface morphology is examined by scanning electron microscope (SEM). The experimental results are summarized as: (1) Compared with conventional grinding (CG), the elliptical vibration leads to a decrease of surface roughness up to 25% in EUAG; (2) The surface roughness has a monotonously increasing trend with the increasing wheel depth of cut in both EUAG and CG, but has little variation with the worktable feed rate. As the wheel speed increases, the surface roughness decreases until it reaches a minimum, and then increases in a monotonous trend in both EUAG and CG; (3) The surface quality in EUAG has a significant improvement, and it is prone to achieve the ductile regime grinding of sapphire compared with CG. These indicate that the elliptical ultrasonic assisted grinding is an efficient technique for high performance machining of monocrystal sapphire.

Experimental Research on Surface Roughness of Ultrasonic Assisted Grinding on 7075 Aluminum Alloy

2021 ◽  
Vol 1047 ◽  
pp. 62-67
Author(s):  
Shen Wang ◽  
Le Tong ◽  
Guang Jun Chen ◽  
Mao Xun Wang ◽  
Bin Dai ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Processing Parameters ◽  
7075 Aluminum Alloy ◽  
Machined Surface ◽  
Ultrasonic Assisted Grinding ◽  
Great Performance ◽  
Ultrasonic Assisted ◽  
Conventional Grinding ◽  
Micro Morphology

7075 aluminum alloy is widely used due to its great performance, especially in aerospace area. In this paper, ultrasonic-assisted grinding technology is used to process 7075 aluminum alloy. The data is obtained through experiments, and the surface roughness and morphology of ultrasonic assisted grinding and conventional grinding under different spindle speeds, feed rates, and amplitudes are analyzed. Research has found that the increase in spindle speed and amplitude will improve the quality of the machined surface and reduce the surface roughness by 82.1% and 36%. However, with the increase of feed rate, the surface quality decreased significantly, and the surface roughness increased by 55.6%. The surface micro-morphology of the machined workpiece is observed, and the effects of different processing parameters on the surface micro-morphology are obtained.

Experimental Study on the Mechanism of Axial Ultrasonic-Assisted Grinding

2012 ◽  
Vol 490-495 ◽  
pp. 2449-2453
Author(s):  
S.X. Yuan ◽  
M. Xiao
Keyword(s):  
Experimental Study ◽  
Grinding Force ◽  
Paper Analysis ◽  
Kinematics Model ◽  
Ultrasonic Assisted Grinding ◽  
Ultrasonic Assisted ◽  
Conventional Grinding

This paper analysis the mechanism of axial ultrasonic-assisted grinding(AUAG), by establishing the kinematics model of a single grit; The reason why AUAG forces are more lower than conventional grinding(CG) forces is presented, and the experiments of the grinding force in AUAG comparison with CG were carried out. The results indicate that the grinding force of the superalloy in AUAG is about 40% to 50% less than that in CG.

Experimental Study on Ultrasonic Assisted Grinding of C/SiC Composites

2014 ◽  
Vol 620 ◽  
pp. 128-133 ◽  
Author(s):  
Kai Ding ◽  
Yu Can Fu ◽  
Hong Hua Su ◽  
Tao He ◽  
Xi Zhai Yu ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Brittle Fracture ◽  
Grinding Force ◽  
Specific Grinding Energy ◽  
Ultrasonic Assisted Grinding ◽  
Ultrasonic Assisted ◽  
Conventional Grinding ◽  
Carbide Matrix ◽  
Sic Composites ◽  
Material Removal Mode

In the present work, ultrasonic assisted grinding (UAG) and conventional grinding (CG, without ultrasonic) tests of Carbon fiber reinforced silicon carbide matrix (C/SiC) composites were conducted. In addition, analysis was done by comparing the machining quality, grinding force, and specific grinding energy between the two processes. The results showed that material removal mode of carbon fiber both in CG and UAG were brittle fracture, and fracture size had no obvious difference. Compared with CG, brittle fracture area of SiC increased during UAG. In comparison with CG, the normal grinding force and tangential grinding force for UAG were reduced maximally by 45%, 39% respectively of those for CG. Accordingly, specific grinding energy was also reduced by UAG. Therefore, UAG can improve the grinding performance of C/SiC composites significantly.

A Three-Dimensional Fractal Analysis Method for Ground Monocrystal Sapphire Surface

2014 ◽  
Vol 1017 ◽  
pp. 187-192
Author(s):  
Qiu Yan Wang ◽  
Zhi Qiang Liang ◽  
Xi Bin Wang ◽  
Wen Xiang Zhao ◽  
Yong Bo Wu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Fractal Dimension ◽  
Fractal Analysis ◽  
Three Dimensional ◽  
Ground Surface ◽  
Surface Characteristics ◽  
Surface Phenomenon ◽  
Analysis Method ◽  
Characterization Methods ◽  
Box Counting

Conventional characterization methods of grinding surface using surface roughness parameters, e.g., Ra, depend on either the resolution of the measuring instrument or the length of the sample. But fractal dimension (FD) as a scale-independent fractal parameter is effective to evaluate the ground surface at any length scale and represent lots of surface phenomenon at its relevant length scales. In this paper, a three-dimensional (3D) box-counting fractal analysis method is used to investigate ground surface morphology of monocrystal sapphire by calculating 3D fractal dimension of the ground surface. The results obtained show that fractal dimension decreases with the increasing surface roughness. For the ground surface with higher fractal dimension, its microtopography is more exquisite with minor defects. Once the fractal dimension become smaller, deep cracks and pronounced defects are exhibited in ground surface. Moreover, the ground surface obtained in ductile mode has much higher fractal dimension than that in brittle mode. Therefore, the fractal analysis method has the potential to reveal the ground surface characteristics of monocrystal sapphire.

Fundamental Investigation of Ultrasonic Assisted Pulsed Electrochemical Grinding of Ti-6Al-4V

2016 ◽  
Vol 874 ◽  
pp. 279-284 ◽  
Author(s):  
Si Si Li ◽  
Yong Bo Wu ◽  
Mitsuyoshi Nomura
Keyword(s):  
Vibration Amplitude ◽  
Material Removal ◽  
Input Voltage ◽  
Grinding Forces ◽  
Work Surface ◽  
Fundamental Investigation ◽  
Ultrasonic Assisted ◽  
Conventional Grinding ◽  
Actual Material ◽  
Electrochemical Grinding

Aiming at the development of a novel grinding technology for the highly efficient machining of difficult to machine materials such as Ti-6Al-4V, an ultrasonic assisted pulsed electrochemical grinding (UAECG) method was proposed. The current work is to reveal the fundamental grinding characteristics of the UAECG of Ti-6Al-4V by experimentally investigating the effect of vibration amplitude on grinding forces, actual material removal and work-surface roughness under different process parameters such as the input voltage and rotational speed. Summarizing the obtained results revealed that the grinding forces in UAECG are significantly smaller than those in conventional grinding (CG).

Grinding Force and Surface Roughness in Ultrasonic Assisted Grinding of SiC Ceramics with Diamond Grinding Wheel

2013 ◽  
Vol 797 ◽  
pp. 234-239 ◽  
Author(s):  
Li Fei Liu ◽  
Fei Hu Zhang ◽  
Chun Hui Li ◽  
Jiang Chen ◽  
Min Hui Liu
Keyword(s):  
Surface Roughness ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Diamond Grinding Wheel ◽  
Ultrasonic Assisted Grinding ◽  
Diamond Grinding ◽  
Sic Ceramics ◽  
Force Ratio ◽  
Ultrasonic Assisted ◽  
Conventional Grinding

In this paper, experiments are conducted to study the characters of Ultrasonic Assisted Grinding (UAG) and Conventional Grinding (CG), diamond grinding wheel is used in experiments, grinding forces and surface roughness are measured in both UAG and CG. The effects of different parameters on grinding force, surface roughness and force ratio are discussed. The results show that the grinding force and surface roughness in UAG is smaller than those in CG. The force ratio in UAG is lower than that in CG, which reveals that the grinding wheel has a good wear-resistant property in UAG process.

A Study on Ultrasonic Assisted Grinding of Nickel-Based Superalloys

2013 ◽  
Vol 797 ◽  
pp. 356-361
Author(s):  
Wen Qing Song ◽  
Yong Bo Wu ◽  
Jian Guo Cao ◽  
Jing Ti Niu
Keyword(s):  
Surface Roughness ◽  
Grinding Wheel ◽  
Grinding Forces ◽  
Work Surface ◽  
Ultrasonic Assisted Grinding ◽  
Nickel Based Superalloy ◽  
Ultrasonic Assisted ◽  
The Face ◽  
Cbn Grinding Wheel ◽  
Face Grinding

Ultrasonic assisted grinding experiments were carried out to evaluate the effects of the ultrasonic vibration (UV) on the face grinding characteristics of nickel based superalloy of Rene77. In experiments, an electroplated cBN grinding wheel was ultrasonically vibrated dominantly along its axis. The experimental results indicated that the X-axis and Y-axis components of grinding forces with UV were smaller by 44.5% and 31.6%, respectively, than those without UV. The usual fractures and debris on the surface of workpiece disappeared and the work-surface roughness Ra was decreased by 42.3% once the UV was applied. The abrasion of the grinding wheel without UV is more serious than that with UV.

Advances in Ultrasonic Assisted Grinding of Ceramic Materials

2006 ◽  
Vol 45 ◽  
pp. 1711-1716 ◽  
Author(s):  
E. Uhlmann ◽  
C. Hübert
Keyword(s):  
Material Removal ◽  
Cfd Simulation ◽  
Ceramic Materials ◽  
Innovative Technology ◽  
Simulation Tools ◽  
Ultrasonic Assisted Grinding ◽  
Lubricant Flow ◽  
Ultrasonic Assisted ◽  
Conventional Grinding ◽  
Cooling Lubricant

The competitiveness of component parts made of advanced ceramics results almost exclusively from the properties of the material in use. However, it is restricted by the constantly high costs of part manufacture especially in the finishing stage. The results of recent investigations being presented in this paper demonstrate an increase in productivity of material removal via the application of the innovative technology of ultrasonic assisted grinding. During the manufacture of through holes or grooves in ceramic materials such as Al2O3, Zr2O, SSN and SiC this process is characterized by significant less process forces and lower process temperatures in comparison with conventional grinding processes. In order to deepen the process knowledge of this modified grinding process two different simulation tools have been introduced. A voxel-based approach for modeling of the material removal as well as CFD-simulation of the unique cooling lubricant flow conditions proved their capability as an optimization tool.

3D Fractal Analysis of Ultra Precision Grinding Influencing on the Surface Topography of Brittle Material

2007 ◽  
Vol 359-360 ◽  
pp. 523-527 ◽  
Author(s):  
Ming Jun Chen ◽  
Qi Long Pang ◽  
Jing He Wang ◽  
Kai Cheng
Keyword(s):  
Fractal Dimension ◽  
Surface Topography ◽  
Brittle Material ◽  
Roughness Parameter ◽  
Ground Surface ◽  
Inverse Relation ◽  
Precision Grinding ◽  
Fractal Method ◽  
Grinding Parameters ◽  
Ultra Precision

3Dfractal dimension and 2D profile fractal dimension distribution of the surfaces made by brittle or ductile grinding are calculated. From the calculated results of 3D fractal dimension, it can be found that the microtopograhpy of ductile ground surface is more exquisite than brittle ground surface and 3D fractal dimension Ds has inverse relation with the roughness parameter Rq. Through the analysis of 2D profile fractal dimension distribution in different ground surfaces, it is revealed that the topography of ground surface is changed with grinding parameters such as ground surfaces may have weakly or strongly anisotropic even isotropic features when different grinding parameters are adopted. Using fractal method to analyze the topography of ground surface is helpful to understand the generating mechanism of surface topography.

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