Precision Grinding of Concave Spherical Surface of High-Alumina

2008 ◽  
Vol 368-372 ◽  
pp. 726-728 ◽  
Author(s):  
Xiao Feng Zhang ◽  
Bin Lin ◽  
Fang Yang Zhang
Keyword(s):  
Spherical Surface ◽  
Alumina Ceramic ◽  
Surface Generation ◽  
High Alumina ◽  
Grinding Wheel ◽  
Machining Parameters ◽  
Precision Grinding ◽  
Cutting Depth ◽  
Critical Cutting Depth ◽  
Single Grain

The performances of high-alumina ceramic are analyzed such as physical and mechanical property. In consideration of its brittleness-ductility change, the critical cutting depth agc of high-alumina ceramic is 3μm. When the cutting depth of single grain is less than the critical cutting depth of alumina ceramic in precision manufacturing, the material is wiped off with ductility. So the cutting depth of single grain agm should be selected within 0.1~2.5μm.Grinding wheel sharp edge is utilized for the spherical surface generation cutting. The ceramic-bonded fine grain diamond wheel is selected after considering manufacturing technology, machining parameters, its making and mending. The granularity of grinding wheel is M1~M5 and the consistence is 125%. The method of spherical surface generation cutting and the effect of high-alumina ceramic ductile machining were verified by the experiment of high-alumina ceramic precision grinding using precision grinding machine MGK1420. The result shows that the surface quality is very high and achieves the requirements.

Research of the Grinding Mode Applied by the Cranfield BoX Ultra Precision Grinding Machine

2013 ◽  
Vol 712-715 ◽  
pp. 553-558
Author(s):  
Zhuang De Jiang ◽  
Shu Ming Yang ◽  
Jin Long Wang ◽  
Guang Tao Yuan ◽  
Xing Yuan Long
Keyword(s):  
Grinding Wheel ◽  
Precision Grinding ◽  
Wheel Surface ◽  
Cutting Depth ◽  
Workpiece Surface ◽  
Ultra Precision ◽  
Simulation Results ◽  
Grinding Machine

In this paper an efficient grinding mode which is employed by the Cranfield BoX ultra precision grinding machine is discussed. The equations of workpiece surface and grinding wheel surface are proposed and the grinding motion is simulated via Matlab. The trajectory of the changing cutting region is discussed. The simulation results show that this grinding mode is suit to manufacture low slope surfaces. Generally, the workpiece surface is steeper, and the cutting range of the machine is smaller. The angle of the spindle inclination, the grinding wheel width and the cutting depth should be chose properly for different manufacturing capacity.

Inclined Axis Ultra-Precision Grinding for Spherical Surface

2011 ◽  
Vol 175 ◽  
pp. 145-149 ◽  
Author(s):  
Shao Hui Yin ◽  
Jing Wang ◽  
Feng Jun Chen ◽  
Jian Wu Yu ◽  
Yu Wang ◽  
...  
Keyword(s):  
Spherical Surface ◽  
Diamond Wheel ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Work Piece ◽  
Precision Grinding ◽  
Wheel Surface ◽  
High Quality ◽  
Alloy Material ◽  
Ultra Precision

Through establishing the mathematical models of velocity and grinding force to optimize the installation angle with inclined axis grinding technology, the spherical surface of the ultra-hard alloy material was ground by formed electroplated diamond wheel. After analyzing the abrasion of grinding wheel, the results show that the inclined axis grinding technology of the formed grinding wheel can avoid the rotation dead spots of grinding wheel, and can make the grinding wheel surface contacted with work-piece fully which could make the worn more evenly. Finally, it obtains a surface in a high quality with the surface roughness of Ra is 12.88nm, and the form accuracy of PV is 124nm.

scholarly journals An Investigation of the Cutting Strategy for the Machining of Polar Microstructures Used in Ultra-Precision Machining Optical Precision Measurement

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 755
Author(s):  
Chen-Yang Zhao ◽  
Chi-Fai Cheung ◽  
Wen-Peng Fu
Keyword(s):  
Precision Measurement ◽  
Detection Algorithm ◽  
Surface Generation ◽  
Precision Machining ◽  
Tool Geometry ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Ultra Precision ◽  
Transition Points ◽  
Cutting Strategy

In this paper, an investigation of cutting strategy is presented for the optimization of machining parameters in the ultra-precision machining of polar microstructures, which are used for optical precision measurement. The critical machining parameters affecting the surface generation and surface quality in the machining of polar microstructures are studied. Hence, the critical ranges of machining parameters have been determined through a series of cutting simulations, as well as cutting experiments. First of all, the influence of field of view (FOV) is investigated. After that, theoretical modeling of polar microstructures is built to generate the simulated surface topography of polar microstructures. A feature point detection algorithm is built for image processing of polar microstructures. Hence, an experimental investigation of the influence of cutting tool geometry, depth of cut, and groove spacing of polar microstructures was conducted. There are transition points from which the patterns of surface generation of polar microstructures vary with the machining parameters. The optimization of machining parameters and determination of the optimized cutting strategy are undertaken in the ultra-precision machining of polar microstructures.

Influence of Supporting Characteristics on Sphericity of Ceramic Balls in Rotated Dual-Plates Lapping Process

2009 ◽  
Vol 69-70 ◽  
pp. 69-73 ◽  
Author(s):  
Bing Hai Lv ◽  
Ju Long Yuan ◽  
F. Cheng ◽  
Fan Yang
Keyword(s):  
Numerical Calculation ◽  
Fourier Analysis ◽  
Support System ◽  
Spherical Surface ◽  
Surface Generation ◽  
Shape Error ◽  
Lower Natural Frequency ◽  
Sinusoidal Waveform ◽  
Higher Spin ◽  
Ball Surface

Ceramic balls have become an important component in advanced bearings, and the sphericity of balls is a key qualification focused in lapping process. An investigation on the effect of dynamic behavior of ball support system on the performance of ball lapping in rotated dual-plates lapping method is carried out. Sinusoidal waveform in terms of Fourier analysis is employed to express the shape error of the ball surface, and a dynamic model for support is setup. It is found with numerical calculation that the variation of lapping load lags behind the variation of the shape error for the damping of support. A lower natural frequency of the support system, higher spin speed of balls and a larger value of spin angle in RDP lapping are better to rectify the shape error of balls and reduce the lagged effect. It is concluded that dynamics of lapping system must be taken into consideration in order to understand comprehensively the spherical surface generation mechanism.

Design on High-Speed Precision Grinder

2006 ◽  
Vol 304-305 ◽  
pp. 492-496 ◽  
Author(s):  
Yu Hou Wu ◽  
L.X. Zhang ◽  
Ke Zhang ◽  
Song Hua Li
Keyword(s):  
High Speed ◽  
Servo Control ◽  
Grinding Wheel ◽  
Control Technology ◽  
Precision Grinding ◽  
Spindle Unit ◽  
Central Controller ◽  
High Speed Grinding ◽  
Dynamic Performances ◽  
Feed Unit

As one of the modern manufacture technology, high-speed precision grinding takes an important part in the modern manufacture field. With the development of the technology on high-speed spindle unit, linear precision high-speed feed unit, manufacture of grinding wheel, measurement etc, a great deal of research achievements make it possible for high-speed precision grinding. In this paper, using PMAC (Programmable Multi-Axis Controller)—PC as the central controller, a new kind of high-speed precision grinder is designed and manufactured. The servo control technology of linear motor is investigated. The dynamic performances of the machine are analyzed according to the experimental results. Elliptical workpieces have been machined with this new high-speed precision grinder. Based on these research results, a very helpful approach is provided for the precision grinding of complicated workpieces, and these results promote the development of high speed grinding too.

Analysis of the effect of tool posture on stability considering the nonlinear dynamic cutting force coefficient

2021 ◽  
pp. 1-19
Author(s):  
Zepeng Li ◽  
Rong Yan ◽  
Xiaowei Tang ◽  
Fang Yu Peng ◽  
Shihao Xin ◽  
...  
Keyword(s):  
Cutting Force ◽  
Nonlinear Dynamic ◽  
Chip Thickness ◽  
Cutting Depth ◽  
Force Coefficient ◽  
Critical Cutting Depth ◽  
Dynamic Cutting Force ◽  
Cutting Force Coefficient ◽  
Tool Posture ◽  
Instantaneous Uncut Chip Thickness

Abstract In aviation and navigation, complicated parts are milled with high-speed low-feed-per-tooth milling to decrease tool vibration for high quality. Because the nonlinearity of the cutting force coefficient (CFC) is more evident with the relatively smaller instantaneous uncut chip thickness, the stable critical cutting depth and its distribution against different tool postures are affected. Considering the nonlinearity, a nonlinear dynamic CFC model that reveals the effect of the dynamic instantaneous uncut chip thickness on the dynamic cutting force is derived based on the Taylor expansion. A five-axis bull-nose end milling dynamics model is established with the nonlinear dynamic CFC model. The stable critical cutting depth distribution with respect to tool posture is analyzed. The stability results predicted with the dynamic CFC model are compared with those from the static CFC model and the constant CFC model. The effects of tool posture and feed per tooth on stable critical cutting depth were also analyzed, and the proposed model was validated by cutting experiments. The maximal stable critical cutting depths that can be achieved under different tool postures by feed per tooth adjustment were calculated, and corresponding distribution diagrams are proposed for milling parameter optimization.

Study on Single-Plane Biaxial Balance Monitor System in ULTRA-Precision Grinding

2006 ◽  
Vol 304-305 ◽  
pp. 251-255
Author(s):  
L. Zheng ◽  
Yin Biao Guo ◽  
Z.Z. Wang
Keyword(s):  
Mutual Influence ◽  
Machining Accuracy ◽  
Monitor System ◽  
Machining Parameters ◽  
Precision Grinding ◽  
Single Plane ◽  
Workpiece Surface ◽  
Surface Error ◽  
Vibration Data ◽  
Ultra Precision

This paper puts forward an intelligent single-plane biaxial balance monitor system, which is used in ultra-precision grinding. It adopts the method of single-plane balance correction for the vibration of wheel and workpiece. And this system can also be used for integral balance. For ultra-precision grinding, caused by the mutual influence of the vibration of wheel and workpiece, there will be a ripple on the workpiece surface, which is mainly influenced by the frequency ratio of wheel to workpiece, the feed rate and the vibration of wheel and workpiece. This system can improve the machining accuracy, reduce the surface error of workpiece and appraise the integrated machining result, by analyzing the vibration data of wheel and workpiece and adjusting machining parameters.

Development of Electroplated CBN Wheel with Cemented Carbide Base for Precision Grinding of Compressor Cylinder Vane Slot

2007 ◽  
Vol 329 ◽  
pp. 495-500
Author(s):  
Hang Gao ◽  
W.G. Liu ◽  
Y.G. Zheng
Keyword(s):  
Surface Roughness ◽  
Ground Surface ◽  
Cemented Carbide ◽  
Grinding Wheel ◽  
Precision Grinding ◽  
Base Surface ◽  
Compressor Cylinder ◽  
Cbn Wheel ◽  
Micro Holes ◽  
Ground Surface Roughness

It is experimentally found that existing micro-holes or micro-concaves on the cemented carbide base surface of electroplated CBN wheel is one of important reasons to worsen the combining intensity of the electroplated abrasives layer with the grinding wheel base. It is well solved by sealing the holes or concaves with steam sealing method. Further more the electroplated CBN wheel with cemented carbide base for precision grinding of compressor cylinder vane slot is developed by optimizing the electroplating prescription and process. Productive grinding results show that the ground surface roughness, size precision and the wheel life have reached the advanced index of the same type of wheel imported.

The Machining Parameters Online Monitoring Method for Stability Prediction

2011 ◽  
Vol 141 ◽  
pp. 559-563
Author(s):  
Yong Xiang Jiang ◽  
San Peng Deng ◽  
Yu Ming Qi ◽  
Bing Du
Keyword(s):  
Dynamic Models ◽  
Grinding Wheel ◽  
Machining Accuracy ◽  
Machining Parameters ◽  
Regenerative Chatter ◽  
Monitoring Method ◽  
Good Surface ◽  
Prediction And Control ◽  
The Stability ◽  
Online Detecting

Unstable grinding due to the regenerative chatter is one of the most critical errors and a serious limitation to achieve good surface quality. The machining accuracy of CNC is greatly depending on online detecting, prediction and control ability of abnormal phenomena in machining such as chatter. Based on the mechanism of regenerative chatter, the dynamic models of cylindrical plunging are established by considering both the rotate speed of workpiece and grinding wheel. The traverse grinding can be assumed as the sum of several stepwise plunging grinding with respect to the grinding contact area. The stability caused by online detecting indexes of grinding parameters was analyzed. Grinding experiments of online chatter detecting were carried out and agreed well with the theoretical results that show good application future for online chatter detecting.

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