Investigation of High-Speed Nanogrinding Mechanism Based on Molecular Dynamics

2018 ◽  
Author(s):  
Yao Liu ◽  
Beizhi Li ◽  
Yihao Zheng
Keyword(s):  
Molecular Dynamics ◽  
Silicon Carbide ◽  
Brittle Material ◽  
High Speed ◽  
Ground Surface ◽  
Wheel Speed ◽  
Depth Of Cut ◽  
Silicon Carbide Ceramic ◽  
Ductile Grinding ◽  
Sic Ceramic

The SiC ceramic ductile grinding, which can obtain crack-free ground surface, is a challenge in brittle material machining. To understand the brittle material ductile grinding mechanism in the nanoscale, a molecular dynamics (MD) model is built to study the single diamond grit grinding silicon carbide ceramic. Through analyzing the MD simulation process, the grit forces the SiC to deform and form the chip through the plastic deformation and flow. The ground surface has no crack on the surface and damage layer thickness is less than one atom layer under the nanoscale depth of cut, which indicates the nanogrinding can achieve the pure ductile grinding for the SiC ceramic and obtain a crack-free and high-quality ground surface. Grinding force, stress, temperature, and specific energy increase with the wheel speed and depth of cut due to the higher grinding speed and a smaller depth of cut can generate a higher density of defects (vacancies, interstitial atoms, and dislocations) on the workpiece, which can make the silicon carbide ceramic more ductile. The high wheel speed is favorable for the ductile grinding.

Study on Edge Contact Area and Surface Integrity of Workpiece in Point Grinding Process

2009 ◽  
Vol 407-408 ◽  
pp. 577-581
Author(s):  
Shi Chao Xiu ◽  
Zhi Jie Geng ◽  
Guang Qi Cai
Keyword(s):  
Surface Integrity ◽  
Contact Area ◽  
High Speed ◽  
Ground Surface ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Edge Contact ◽  
Cylindrical Grinding ◽  
Theoretic Foundations

During cylindrical grinding process, the geometric configuration and size of the edge contact area between the grinding wheel and workpiece have the heavy effects on the workpiece surface integrity. In consideration of the differences between the point grinding and the conventional high speed cylindrical grinding, the geometric and mathematic models of the edge contact area in point grinding were established. Based on the models, the numerical simulation for the edge contact area was performed. By means of the point grinding experiment, the effect mechanism of the edge contact area on the ground surface integrity was investigated. These will offer the applied theoretic foundations for optimizing the point grinding angles, depth of cut, wheel and workpiece speed, geometrical configuration and size of CBN wheel and some other grinding parameters in point grinding process.

High-speed processing of silicon carbide ceramic by high repetition frequency femtosecond laser

2021 ◽  
Author(s):  
Jian Zhang ◽  
Feng Geng ◽  
Zhichao Liu ◽  
Qinghua Zhang ◽  
Qiao Xu ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Femtosecond Laser ◽  
High Speed ◽  
Repetition Frequency ◽  
Silicon Carbide Ceramic ◽  
High Repetition

Temperature Measurement of Workpieces in Conventional Surface Grinding

1998 ◽  
Vol 122 (2) ◽  
pp. 297-303 ◽  
Author(s):  
T. Kato ◽  
Hiroshi Fujii
Keyword(s):  
Thin Film ◽  
Ground Surface ◽  
Wheel Speed ◽  
Surface Grinding ◽  
Maximum Temperature ◽  
Depth Of Cut ◽  
Thermal Sensor ◽  
Moving Heat Source ◽  
Pvd Film ◽  
Film Method

Temperature at various depths from the ground surface in workpiece is measured accurately by using the newly developed PVD film method, in which a thin film deposited on the workpiece is used as a thermal sensor. The influence of workpiece speed, depth of cut and wheel speed on the temperature of the workpiece was investigated under conventional surface grinding with no grinding fluids. The measured results were compared with Takazawa’s approximation based on Jaeger’s heat conduction solution to the moving heat source problem. The maximum temperature rise at the surface and the temperature gradient close to the surface were obtained and correlated with the residual stress induced at the surface. [S1087-1357(00)70302-9]

scholarly journals Ductile grinding of Silicon carbide in high speed grinding

2016 ◽  
Vol 10 (2) ◽  
pp. JAMDSM0020-JAMDSM0020 ◽  
Author(s):  
Chongjun WU ◽  
Beizhi LI ◽  
Jingzhu PANG ◽  
Steven Y. LIANG
Keyword(s):  
Silicon Carbide ◽  
High Speed ◽  
Ductile Grinding ◽  
High Speed Grinding

Comparative Study of Biomorphic Silicon/Silicon Carbide Ceramic from Birch and Compressed Birch

2010 ◽  
Vol 434-435 ◽  
pp. 609-612 ◽  
Author(s):  
Zi Li Yan ◽  
Jie Liu ◽  
Jian Chun Zhang ◽  
Tian Ma ◽  
Zheng Cao Li
Keyword(s):  
Silicon Carbide ◽  
Treatment Method ◽  
Compression Process ◽  
Silicon Carbide Ceramic ◽  
Sic Ceramics ◽  
Carbon Template ◽  
Wood Compression ◽  
Sic Ceramic ◽  
Pre Treatment ◽  
Silicon Silicon

Wood compression process was innovatively introduced as a pre-treatment method to birch into the fabrication of biomorphic silicon/silicon carbide (Si/SiC) ceramic with high density. Firstly, birch blocks were compressed to the density in the range of 0.85-1.00g/cm3. Secondly, both birch blocks and compressed birch blocks were carbonized at 1200°C to get carbon templates. Lastly, carbon templates were infiltrated with liquid silicon to obtain biomorphic Si/SiC ceramics. The effect of compression process on the density and microstructure of both carbon template and ceramic was investigated. The results show that the maxium density of biomorphic Si/SiC ceramic from compressed birch is 3.01g/cm3, whereas the density of the ceramic from birch is only 2.80-2.89g/cm3. So the compression process was an effective method to increase the density of biomorphic Si/SiC ceramic.

Experimental Investigations on Cylindrical Grinding Temperature of Silicon Carbide

2015 ◽  
Vol 1120-1121 ◽  
pp. 1251-1256 ◽  
Author(s):  
Chong Jun Wu ◽  
Bei Zhi Li ◽  
Steven Y. Liang ◽  
Jian Guo Yang
Keyword(s):  
Silicon Carbide ◽  
High Speed ◽  
Ground Surface ◽  
High Energy ◽  
Dynamics Simulation ◽  
Distribution Model ◽  
Experimental Investigations ◽  
Grinding Temperature ◽  
Temperature Characteristics ◽  
High Speed Grinding

The grinding process requires a high energy expenditure per unit volume of material removed. The high temperature generated in abrasive processes is the main factor responsible for thermal damage to a ground surface. An investigation was undertaken to explore the temperature characteristics in high speed grinding (HSG) of silicon carbide (SiC) with a vitrified diamond wheel. A grindable thermocouople technique including a NI-DAQ device will be used to measure the grinding temperature. This paper will discuss the temperature characteristics in high speed grinding of SiC in detail and give an experiment-based temperature distribution model for SiC. A molecular dynamics simulation will be used to illustrate the effect of a high loading rate on SiC material’s mechanical property, which will further elaborate its unique HSG temperature characteristics. The experimental investigation will provide more practical application support in utilizing HSG technology in a high quality ceramic grinding.

Surface Quality of High Speed Milling of Silicon Carbide by Using Diamond Coated Tool

2013 ◽  
Vol 446-447 ◽  
pp. 275-278 ◽  
Author(s):  
Mohammad Iqbal ◽  
Mohamed Konneh ◽  
Ahmad Yasir Bin Md Said ◽  
Azri Fadhlan Bin Mohd Zaini
Keyword(s):  
Surface Roughness ◽  
Silicon Carbide ◽  
High Speed ◽  
Cutting Parameters ◽  
Machining Process ◽  
Depth Of Cut ◽  
Work Piece ◽  
Model Interaction ◽  
High Speed Milling ◽  
Coated Tool

The high speed milling of silicon carbide was discussed by using flat end-mill 2 mm in diameter diamond coated tool. Ultra-precision high speed spindle attachment was used to achieve cutting tool rotation speed as high as 50,000 rpm. Special fixture was designed to minimize the chatter on work-piece surface during the machining process. Three cutting parameters were selected as independent variables of the experiments. They were spindle speed, depth of cut and feed rate. The arithmetic mean value of roughness (Ra) was measured on the work-piece surface as the response of the experiment. Result of the experiment shows that the value of surface roughness can be achieved as low as 0.150 μm. Statistical analysis was provided to study the significant of the model, interaction among the cutting parameters and their effects to the surface roughness value.

scholarly journals Efficient and Precise Grinding of Sapphire Glass Based on Dry Electrical Discharge Dressed Coarse Diamond Grinding Wheel

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 625 ◽  
Author(s):  
Yanjun Lu ◽  
Wang Luo ◽  
Xiaoyu Wu ◽  
Chaolan Zhou ◽  
Bin Xu ◽  
...  
Keyword(s):  
Surface Quality ◽  
Electrical Discharge ◽  
Ground Surface ◽  
Grinding Force ◽  
Wheel Speed ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Feed Speed ◽  
Diamond Grinding Wheel ◽  
Diamond Grinding

In this paper, in view of low grinding efficiency and poor ground surface quality of sapphire glass, the coarse diamond grinding wheel dressed by dry impulse electrical discharge was proposed to perform efficient and precise grinding machining of sapphire glass. The dry electrical discharge dressing technology was employed to obtain high grain protrusion and sharp micro-grain cutting edges. The influences of grinding process parameters such as wheel speed, depth of cut and feed speed on the ground surface quality, grinding force and grinding force ratio on sapphire glass were investigated, and the relationship between grinding force and ground surface quality was also revealed. The experimental results show that the grain protrusion height on the surface of a coarse diamond grinding wheel dressed by dry electrical discharge can reach 168.5 µm. The minimum line roughness Ra and surface roughness Sa of ground sapphire glass surface were 0.194 µm and 0.736 µm, respectively. In order to achieve highly efficient ground quality of sapphire glass, the depth of cut was controlled within 7 µm, and the wheel speed and feed speed were 3000–5000 r/min and 10–20 mm/min, respectively. The influences of feed speed and wheel speed on grinding force ratio were more significant, but the influence of depth of cut was little.

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