Analysis on the Factors of Surface Morphologies on Si3N4 Ceramic Internal Grinding

2017 ◽  
Vol 31 ◽  
pp. 44-52
Author(s):  
Jian Sun ◽  
Peng Zhou ◽  
Yu Hou Wu ◽  
Ke Zhang ◽  
Li Xiu Zhang
Keyword(s):  
Silicon Nitride ◽  
Grinding Wheel ◽  
Axial Vibration ◽  
Machined Surface ◽  
Silicon Nitride Ceramic ◽  
Linear Speed ◽  
Internal Grinding ◽  
Grinding Parameters ◽  
Feeding Speed ◽  
Surface Morphologies

Different grinding parameters of silicon nitride ceramic are researched at the process of internal grinding. The influences on the roughness of surface by the linear speed of grinding wheel (vs), radial feeding speed (f) and axial vibration speed (fa) are studied in the uniformity testing. The experimental equation of silicon nitride ceramic internal grinding is optimized. The machined surface morphologies of the ceramic specimen are measured by roughness instrument of Taylor-Hobson Surtroni-25 and scanning electron microscope of S-4800. The results show that with the increasing of the linear speed of grinding wheel the roughness of surface get reduced, and with the increasing of radial feeding speed the roughness of surface get raised. It is also inversely proportional to the axial vibration speed. The linear speed of grinding wheel has the biggest impact on the roughness of surface of the silicon nitride ceramic internal grinding among the three grinding parameters. With the increasing of linear speed of grinding wheel, the value of roughness of surface declines from 0.4095μm to 0.1726μm. The influences on the roughness of surface of the silicon nitride ceramic internal grinding by different factors are found out in the research, and its removal mechanisms are cleared up under different linear speeds of grinding wheel.

Experimental Research on High Speed Grinding of Silicon Nitride Ceramic Spindle

2016 ◽  
Vol 874 ◽  
pp. 253-258
Author(s):  
Ke Zhang ◽  
Jian Sun ◽  
He Wang ◽  
Yu Hou Wu
Keyword(s):  
Silicon Nitride ◽  
High Speed ◽  
Linear Velocity ◽  
Grinding Wheel ◽  
Feed Speed ◽  
Silicon Nitride Ceramic ◽  
Technical Parameters ◽  
Internal Grinding ◽  
Brittle Rupture ◽  
High Speed Grinding

Grinding is a main method of silicon nitride ceramic in finish machining stage. The technical parameters had an important influence on the surface quality of silicon nitride ceramic. The silicon nitride ceramic spindle was ground by the high-speed cylindrical grinder MGKS1432-H. The relations between different speed parameters and surface roughness were researched. The cylindrical and internal high speed grinding experiments of silicon nitride ceramics spindle were carried out. The S-4800 scanning electron microscope was used to explore the roughness change rule of the grinded surface under the condition of only changed grinding wheel’s velocity. In the process of cylindrical and internal grinding on silicon nitride ceramic spindle, the roughness tended to decrease with the linear velocity increasing, and increased with the radial feed speed increasing and decreased with the wheel shaft’s oscillation speed increasing. The result indicated that the linear velocity of grinding wheel influenced the sample’s roughness most. The effect of radial feed speed on the roughness is next only to the effect from linear velocity. The effect of shaft’s oscillation speed on the roughness is the lowest of the three factors. In the process of internal grinding, with the linear velocity increasing, the ceramic material transformed from brittle rupture to plastic deformation and the roughness appeared one peak. These results were very helpful to optimize the grinding parameters and improve grinding efficiency.

scholarly journals Polishing of Silicon Nitride Ceramic Balls by Clustered Magnetorheological Finish

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 304
Author(s):  
Xiao-lan Xiao ◽  
Guang-xian Li ◽  
Hai-juan Mei ◽  
Qiu-sheng Yan ◽  
Hua-tay Lin ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Analytical Model ◽  
Surface Finish ◽  
Experimental Results ◽  
Machined Surface ◽  
Silicon Nitride Ceramic ◽  
Ceramic Ball ◽  
Contact Points ◽  
Micro Morphology ◽  
Improve Surface Finish

In this study, a novel finishing method, entitled clustered magnetorheological finish (CMRF), was proposed to improve surface finish of the silicon nitride ( Si 3 N 4 ) balls with ultra fine precision. The effects of different polishing parameters including rotation speeds, eccentricities and the machining gaps on surface finish of Si 3 N 4 balls were investigated by analyzing the roughness, sphericity and the micro morphology of the machined surface. The experimental results showed that the polishing parameters significantly influenced the surface finish. The best surface finish was obtained by using the polishing parameters: the machining gap of 0.8 mm, the eccentricity of 10 mm and the rotation ratio of 3/4. To further investigate the influence of the polishing parameters on the surface finish, an analytical model was also developed to analyze the kinematics of the ceramic ball during CMRF process. The resulting surface finish, as a function of different polishing parameters employed, was evaluated by analyzing the visualized finishing trace and the distribution of the contact points. The simulative results showed that the distribution and trace of the contact points changed with different polishing parameters, which was in accordance with the results of experiments.

Form Accuracy of Internal Grinding of Small and Deep Holes with Coolant Supplied from Inner Side of Grinding Wheel

2014 ◽  
Vol 1017 ◽  
pp. 50-54 ◽  
Author(s):  
Kosaku Matsubara ◽  
Jun Tsuchimura ◽  
Shota Kawazoe ◽  
Hiroyuki Sasahara
Keyword(s):  
Supply System ◽  
Grinding Wheel ◽  
Machined Surface ◽  
Steel Cylinder ◽  
Form Accuracy ◽  
Internal Grinding ◽  
Machining Center ◽  
Grinding Fluid ◽  
Grinding Conditions ◽  
Coolant System

Generally, grinding fluid is supplied from a nozzle to a grinding point. However, it is difficult to supply sufficient coolant to the deep grinding point of a hole. Therefore, we have proposed an alternative coolant system that supplies grinding fluid from the inner side of the grinding wheel utilizing the spindle through the supply system of the machining center. In this study, a new tool for small and deep holes was developed to supply grinding fluid in this way. The inside of a 0.45%C steel cylinder was then machined under various grinding conditions. Higher form accuracy and surface roughness were obtained under all conditions by supplying grinding coolant from the inner side of the grinding wheel. In addition, the system prevented tears on the machined surface and loading on the grinding wheel.

Research on the Influence of NС Quick-Point Grinding Parameters to Complex Rotator Surface Roughness

2014 ◽  
Vol 556-562 ◽  
pp. 1083-1086
Author(s):  
Kai Wang ◽  
Wan Chen Sun ◽  
Feng Ming Nie ◽  
Qing Tang Wu ◽  
Huan Wu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Rotational Speed ◽  
Wheel Speed ◽  
Grinding Wheel ◽  
Test Results ◽  
Shaft Speed ◽  
Linear Speed ◽  
Grinding Parameters ◽  
Grinding Machine ◽  
The Relationship

It studies the influence of linear speed of grinding wheel and rotational speed of workpiece to complex rotator surface roughness. Using self-designed NC quick-point grinding machine do the grinding test at different linear speeds of grinding wheel and different rotational speeds of workpiece, gained the relationship curve between the linear speed of grinding wheel, rotational speed of workpiece and complex rotator surface roughness. The test results show that using quick-point grinding technology can grind multiple external cylindrical and cone-shaped surfaces by only one time fixing, it can get 0.025um surface roughness in a reasonable condition of the grinding parameters. During point grinding process, higher wheel speed gets better surface roughness, higher workpiece shaft speed gets worse surface roughness.

Improvement of Surface Roughness with Micro-Axial Vibration of Spindle by Pressure Pulsation of Grinding Fluid Supplied through inside of Wheel

2016 ◽  
Vol 1136 ◽  
pp. 673-677
Author(s):  
Kosaku Nomura ◽  
Naoya Takeuchi ◽  
Atsushi Kusakabe ◽  
Masahisa Chino ◽  
Hiroyuki Sasahara
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Pressure Pulsation ◽  
Grinding Wheel ◽  
Axial Vibration ◽  
Machined Surface ◽  
Plunger Pump ◽  
Abrasive Grains ◽  
Abrasive Grain ◽  
Grinding Fluid

In grinding, the moving trajectories of abrasive grains are almost straight to the motion of the rotation and feed of the grinding wheel, so that grinding marks are formed continuously. As a result, surface roughness is dependent on grain size and organization of the grinding wheel. If the trajectory of the abrasive grain is wavy, the peak lines of the grinding marks will be partially removed by following the abrasive grain. This improves surface roughness. The objective of this study is to develop a mechanism to give axial vibration to the grinding wheel by the pulsation of the plunger pump, and thus to improve the surface roughness of the machined surface.

Research on Diamond Wheel’s Specialties during ELID Ulterprecision Grinding of Silicon Nitride

2011 ◽  
Vol 295-297 ◽  
pp. 51-55
Author(s):  
Wei Dong Jin
Keyword(s):  
Silicon Nitride ◽  
Surface Profile ◽  
Grinding Wheel ◽  
Cutting Depth ◽  
Insulator Layer ◽  
Silicon Nitride Ceramic ◽  
Workpiece Surface ◽  
Abrasive Grain ◽  
Materials Research ◽  
Hard And Brittle Materials

Taking ultraprecision grinding of silicon nitride ceramic as an example, this paper mostly introduces some influences of diamond wheel’s specialties on the grinding process and surface quality during ELID (electrolytic in-process dressing) grinding of hard and brittle materials. Research indicates that grain size and concentration of abrasive material should be reasonably selected based on the surface roughness. And Inhomogeneity of concentration distribution along wheel circumference will result in heterogeneity of insulator layer state, which will bring difference in the number of abrasive grain in the grinding area, thereby changing the actual cutting depth of every abrasive grain. Dynamic balancing of grinding wheel should be accurately adopted to reduce eccentric mass, furtherly to avoid generating waveness on the workpiece surface. For the purpose of reflecting rightly compositive effect from eccentricity of wheel shape, roundness of the wheel and periodical vibration derived from eccentric mass, actual radial runout of grinding wheel should be well and truly measured and controlled based on the wheel’s surface profile during wheel is rotating at working speed.

Research on Grinding Force of Zirconia Internal Grinding with Resin Bond Diamond Wheel

2016 ◽  
Vol 1136 ◽  
pp. 30-35
Author(s):  
He Wang ◽  
Ke Zhang ◽  
Yu Hou Wu ◽  
Hong Song
Keyword(s):  
Grain Size ◽  
Surface Quality ◽  
Diamond Wheel ◽  
Grinding Force ◽  
Wheel Speed ◽  
Zirconia Ceramic ◽  
Machined Surface ◽  
Research Results ◽  
Internal Grinding ◽  
Machined Surface Quality

The zirconia parts are limited by machined surface quality. The grinding force is one of the most important parameters of grinding and has effects on surface quality. The MK2710 grinder and resin bond diamond wheels were used in zirconia grinding. The grinding force was obtained by Kistler dynamometer. The paper focused on wheel speed and grain size on grinding force, and examined the surface by SEM. The research results indicated that decreasing the grain size, the grinding force increased and the surface quality improved, and increasing wheel speed could decrease grinding force to improve grinding surface quality. The results can improve zirconia ceramic parts surface quality and promote application.

scholarly journals Experimental Study on Grinding Force of Zirconia Ceramics in Dry/Wet Grinding Environment

2018 ◽  
Vol 198 ◽  
pp. 02004
Author(s):  
Junping Zhang ◽  
Weidong Wang ◽  
Songhua Li ◽  
Han Tao
Keyword(s):  
Grinding Force ◽  
Grinding Wheel ◽  
Feed Speed ◽  
Zirconia Ceramics ◽  
Grinding Forces ◽  
Measuring Device ◽  
Linear Speed ◽  
Wet Grinding ◽  
Dry Grinding ◽  
Force Ratio

The impacts of different linear speed of grinding wheel, grinding depth and workpiece feed speed with or without grinding fluid on grinding force were studied by plane grinding machining of zirconia ceramics. The impacts of different machining environment and grinding parameter on normal and tangential grinding forceswere studied by testing the grinding force during grinding with a force measuring device. The studies showed that the normal and tangential grinding forces decrease with the increase of the linear speed of grinding wheel and increase with the improvement of grinding depth and workpiece feed speed. The grinding depth has the greatest impacts on the normal and tangential grinding forces in dry grinding environment; while in wet grinding environment, the grinding depth exerts the greatest impacts on the normal grinding force and the linear speed of grinding wheel imposes the greatest impacts on the tangential grinding force. In addition, it was found that the normal grinding force in dry grinding is minor than that in wet grinding, that the tangential grinding force in dry grinding is greater than that in wet grinding, and that the grinding force ratio in dry grinding is lower than that in wet grinding.

scholarly journals Experiment on Foreign Object Damage of Gas Turbine-Grade Silicon Nitride Ceramic

1998 ◽  
Author(s):  
Hiro Yoshida ◽  
Takashi Nakashima ◽  
Makoto Yoshida ◽  
Yasushi Hara ◽  
Toru Shimamori
Keyword(s):  
Elevated Temperature ◽  
Silicon Nitride ◽  
Elevated Temperatures ◽  
Tensile Load ◽  
Strength Degradation ◽  
Spall Fracture ◽  
Silicon Nitride Ceramic ◽  
Impact Tests ◽  
The Impact ◽  
Bending Fracture

A new high quality turbine system using monolithic silicon-nitride ceramic is under development. In this study particle impact tests of the silicon-nitride have been tried at room and elevated temperatures with and without tensile load, which simulates centrifugal force of blade rotation. In the experiment 1 mm diameter particle is impacted at velocities up to 900 m s−1. In this paper, critical velocities for bending fracture and Hertzian cracks are examined. Moreover, strength degradation at elevated temperature and spall fracture of the blade are discussed. The main results are: 1) The bending fracture mode critical impact velocity for soft particles is higher than that for hard particles. 2)The impact parameter ϕ for initiation of Hertzian cracks ranges 1.08×10−5 – 1.56×10−5 for the materials tested. 3)Strength degradation at elevated temperature was clearly observed. 4) In the impact tests on blades spall fracture, which was caused by interaction of stress waves, appeared.

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