Study on the Phase Transition Characteristics in Ultrasonic High Efficiency Lapped Surface of Engineering Ceramics

2009 ◽  
Vol 416 ◽  
pp. 588-592
Author(s):  
Feng Jiao ◽  
Bo Zhao ◽  
Yong Zhao ◽  
Tai Ping Li
Keyword(s):  
Phase Transition ◽  
Tetragonal Phase ◽  
High Speed ◽  
High Efficiency ◽  
Surface Phase ◽  
Surface Residual Stress ◽  
Machined Surface ◽  
Engineering Ceramics ◽  
Surface Machining ◽  
Machining Quality

Surface phase structure has an important effect on the surface machining quality. The surface phase transition characteristics of ZrO2 and ZTA ceramics under different machining methods were tested by X-ray diffraction in the paper. Through the qualitative and quantitative phase analyses, the influences of several different precision machining methods on the phase transitions in the machined surface were studied. Research results show that there are more transitions from tetragonal phase ZrO2 to monoclinic phase ZrO2 in the high speed grinding surface; because of the high-frequency vibration of lapping tool in ultrasonic lapping, the stress condition in the grinding area can be improved and the stable tetragonal phase ZrO2 in the ultrasonic lapped surface is easy to get. The research conclusions have important significance on analyzing the surface residual stress and improving the surface machining quality of engineering ceramics.

Experimental Study on the Characteristics of Surface Roughness in Ultrasonic Aided High-Speed Lapping of Engineering Ceramics

2010 ◽  
Vol 135 ◽  
pp. 303-308
Author(s):  
Feng Jiao ◽  
Bo Zhao ◽  
Xiang Liu
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Material Removal ◽  
High Speed ◽  
Physical And Mechanical Properties ◽  
Machined Surface ◽  
Engineering Ceramics ◽  
Machining Quality ◽  
Different Characteristics ◽  
Diamond Abrasive

The surface roughness of machined surface is one of the important indicators to evaluate the workpiece machining quality. In order to clarify the change law of surface roughness in ultrasonic aided high-speed lapping with solid diamond abrasive, a series of ultrasonic and conventional lapping experiments of different engineering ceramics, such as Al2O3, ZrO2 and ZTA, were carried out on precision lathe with self-made high-speed ultrasonic lapping device. The research results show that the value of surface roughness in ultrasonic aided lapping is lower than that in conventional lapping. With the assistance of ultrasonic vibration, the surface quality can be improved obviously. In ultrasonic aided lapping, there is an optimum lapping pressure from which a better surface roughness value can be obtained. Because of different physical and mechanical properties, material removal mechanisms of the three kinds of engineering ceramics present different characteristics, which lead to the different surface roughness even though under the same lapping conditions. The research of the paper is helpful to optimize lapping technique and improve the surface quality.

Influences of Ultrasonic Assistance in High Speed Lapping of Nano ZTA Engineering Ceramic on the Surface Machining Quality

2007 ◽  
Vol 359-360 ◽  
pp. 355-359 ◽  
Author(s):  
Feng Jiao ◽  
Bo Zhao ◽  
Chuan Shao Liu ◽  
Xun Sheng Zhu
Keyword(s):  
High Speed ◽  
Chip Thickness ◽  
Surface Profile ◽  
Abrasive Material ◽  
Regular Surface ◽  
Surface Machining ◽  
Machining Quality ◽  
Engineering Ceramic ◽  
Precision Finishing

Ultrasonic aided high speed lapping with solid abrasive material was put forward aimed at the precision finishing of nano ZTA engineering ceramic. Through theoretical analysis and contrast lapping experiments, the influences of ultrasonic assistance on the surface machining quality were clarified. Research results show that the maximum undeformed chip thickness in ultrasonic aided lapping is smaller than that in conventional lapping under the same conditions; ultrasonic assistance is beneficial to enlarging the range of ductile lapping regime and improving the surface quality of nano ZTA ceramic; with the application of ultrasonic vibration, smaller surface roughness and more regular surface profile can be obtained.

Investigation on surface residual stress distribution and evaluation of engineering ceramics in rotary ultrasonic grinding machining

2016 ◽  
Vol 231 (15) ◽  
pp. 2773-2782 ◽  
Author(s):  
SL Wei ◽  
H Zhao ◽  
JT Jing ◽  
FH Yun ◽  
XL Li
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Stress Tolerance ◽  
Surface Integrity ◽  
Residual Stress Distribution ◽  
Distribution Model ◽  
Surface Residual Stress ◽  
Machined Surface ◽  
Engineering Ceramics ◽  
Ultrasonic Grinding

Residual stress of engineering ceramics is one of surface integrity evaluation indexes affecting the parts’ strength properties. Rotary ultrasonic grinding machining is the most powerful machining method for engineering ceramics with better surface integrity. The residual stress field distribution is changed due to micro cracks which are inevitable in the process. A residual stress distribution model of machined surface micro crack tip has been established in the paper. And the experimental results enable us to obtain surface residual stress distribution of engineering ceramics in rotary ultrasonic grinding machining. Then, we propose an evaluation parameter called confidence stress tolerance to evaluate surface residual stress characteristic. Preliminary results indicate that surface residual stress distribution is in line with the normal distribution. Confidence stress tolerance is an effective parameter to improve the evaluation reliability. Furthermore, precision and affecting factors of confidence stress tolerance evaluation have also been investigated.

Surface Topography Characteristics in Ultrasonic Aided High Speed Lapping of Engineering Ceramics

2008 ◽  
Vol 53-54 ◽  
pp. 273-278
Author(s):  
Feng Jiao ◽  
Bo Zhao ◽  
T.P. Li ◽  
Y. Zhao
Keyword(s):  
Surface Topography ◽  
Material Removal ◽  
High Speed ◽  
Good Method ◽  
Ductile Material ◽  
Material Removal Mechanism ◽  
Engineering Ceramics ◽  
Machining Quality ◽  
The Difference ◽  
Unique Surface

Because of its high machining efficiency and good machining quality, ultrasonic aided high-speed lapping with solid abrasive is regarded as a good method of cylindrical machining for engineering ceramics. Compared with conventional lapping, ultrasonic aided high speed lapping has unique surface topography distribution characteristics for the difference of the surface formation mechanism and material removal mechanism. In the paper, the surface topography characteristics of engineering ceramics in different lapping mode were researched. Research results show that the lapped surfaces with and without ultrasonic assistance present different surface topography characteristics. Under the same lapping mode, the lapped surface topography is distinctly different for different ceramics. With the assistance of ultrasonic vibration, more ductile material removal can be obtained and the surface quality can be improved correspondingly.

Mechanism Analysis of High Efficiency Axial Turn-Grinding of Engineering Ceramics

2011 ◽  
Vol 487 ◽  
pp. 376-380 ◽  
Author(s):  
Xin Li Tian ◽  
Fang Guo ◽  
Ya Tao Mao ◽  
Bao Guo Zhang ◽  
Jian Quan Wang ◽  
...  
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Cutting Edge ◽  
Work Piece ◽  
Mechanism Analysis ◽  
Machined Surface ◽  
Effective Removal ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
A Minor

Axial turn-grinding is a method to cut the cylindrical work piece along its axis, using the kinetic energy of high-speed rotation annularity tool, the abrasives in tool tip as the main cutting edge to remove materials and the abrasives in the inside or outside surface of tool as a minor cutting edge to sharpen the processed surface. Through analysis the simplified model, a slightly stress concentration was found at the junction surface of processed surface and machined surface, which had little damage to the workpiece because of happening in the part to be removed or precision machining allowance, and both cracks propagation caused by material rupture were effective removal after material removal mechanism analysis because the extension of the median/radial crack and lateral crack were both happening in the part to be removed.

Research on Ultrasonic-Assisted Fixed-Abrasive Lapping Technology for Engineering Ceramics Cylindrical Part

2017 ◽  
Vol 5 (2) ◽  
Author(s):  
Feng Jiao ◽  
Bo Zhao
Keyword(s):  
Ultrasonic Vibration ◽  
Material Removal ◽  
High Efficiency ◽  
Removal Rate ◽  
Tangential Force ◽  
Cylindrical Part ◽  
Engineering Ceramics ◽  
Machining Quality ◽  
Ultrasonic Assisted ◽  
Fixed Abrasive

Lapping is a key processing step for precision parts, which directly affects machining quality, precision, and efficiency. Due to some drawbacks of free-abrasive lapping such as deep scratches on the lapped surface, lower lapping efficiency for lower lapping speed, severe waste of abrasive, high-processing cost, and so on, conventional fixed-abrasive lapping (CFL) technology was proposed and developed recently. Meanwhile, considering the unique advantages of the ultrasonic-assisted machining during the processing of those hard and brittle materials and the effect of ultrasonic vibration on the self-sharpening characteristic of abrasive pellet, a novel ultrasonic-assisted fixed-abrasive lapping (UAFL) technology is put forward and corresponding lapping device for engineering ceramics cylindrical part is developed in this paper. Meanwhile, UAFL mechanism and characteristics were studied theoretically and experimentally. Research results show that superimposed ultrasonic vibration changes the lapping movement characteristics and material removal mechanism to a certain extent, helping to heighten material removal rate, smoothen the waveform of tangential force, reduce the average tangential force, and improve surface machining quality. UAFL can be regarded as a high efficiency and precision processing technology for engineering ceramics cylindrical part.

scholarly journals Study on Cutting Form and Surface Machining Quality of Wheel Tread under Reprofiling

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Jianxi Wang ◽  
Xin Xue ◽  
Yongjie Lu
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Element Model ◽  
Maintenance Cost ◽  
Serrated Chip ◽  
Machined Surface ◽  
Surface Machining ◽  
Machining Quality

The wheelset maintenance cost is an important part of train maintenance cost. Researchers and railway operators have been closely concerned about the way to minimize residual stress at wheel tread and surface roughness during wheel reprofiling, thereby reducing the wheel damage during operation, extending the wheelset service life, and cutting down wheelset maintenance cost. The present study involves dynamic simulation of tread reprofiling process by building a finite element model of wheel reprofiling, taking the wheel steel as research object. This paper makes a comprehensive analysis of surface roughness and residual stress distribution of wheel tread under different milling parameters. The simulation results indicate that the increase in cutting speed and back cutting depth causes the chip morphology to change while impairing the machined surface quality. Once serrated chip occurs, it means wheel tread machining quality deteriorates remarkably. In this way, the paper associates macroscopic chip morphology with microcosmic surface roughness and internal residual stress to provide theoretical basis for optimization of wheel reprofiling process.

Investigation on Axial Turning-Grinding of Engineering Ceramics

2010 ◽  
Vol 154-155 ◽  
pp. 1027-1032 ◽  
Author(s):  
Xin Li Tian ◽  
Fang Guo ◽  
Ya Tao Mao ◽  
Jian Quan Wang ◽  
Sen Xu ◽  
...  
Keyword(s):  
Axial Force ◽  
Feed Rate ◽  
High Speed ◽  
High Efficiency ◽  
Low Cost ◽  
Cutting Edge ◽  
Transverse Cracks ◽  
Engineering Ceramics ◽  
Damage Degree ◽  
Cylindrical Workpiece

Axial turning-grinding is a processing method to cut the cylindrical workpiece along its axis, using the kinetic energy of high-speed rotation annularity tool, the abrasives in tool tip as the main cutting edge to remove materials and the abrasives in the outside surface of tool as a minor cutting edge to sharpen the processed surface. Comparing with concentric axial turning-grinding, eccentric axial turning-grinding has higher efficiency. The result indicated that cutting thickness and feed rate could be more than 5~10mm and 200mm/min respectively in a cutting, realizing high-efficiency, low-cost processing of engineering ceramics. According to axial force, chips’ shape and damage degree of surface to be processed, obtaining the proper feed rate range. Removal mechanism analyses showed that both median/radial cracks and lateral cracks occurred in the part to be removed, and the intensity of the processed part had little destroyed, only needing adjust axial force to control the length of transverse cracks.

Investigation on Tool Wear about High Efficient Axial Turning-Grinding of Engineering Ceramics

2012 ◽  
Vol 426 ◽  
pp. 89-92 ◽  
Author(s):  
X.L. Tian ◽  
Fang Guo ◽  
Ya Tao Mao ◽  
B.G. Zhang ◽  
Jian Quan Wang ◽  
...  
Keyword(s):  
Tool Wear ◽  
High Speed ◽  
High Efficiency ◽  
Low Cost ◽  
Cutting Edge ◽  
Engineering Ceramics ◽  
High Efficient ◽  
High Speed Rotation ◽  
Cylindrical Workpiece ◽  
A Minor

Axial turning-grinding is a processing method to cut cylindrical workpiece or inner surface of hole along its axis, using the kinetic energy of high-speed rotation annularity tool, the abrasives in tool tip as the main cutting edge to remove materials and the abrasives in the outside surface of tool as a minor cutting edge to sharpen the processed surface. And the cutting thickness and feed rate could be more than 5~10mm and 200mm/min respectively in a cutting, realizing high-efficiency, low-cost processing of engineering ceramics. Using the method, the ceramic sleeve of delivery valve precision coupling components in the engine is processed with high efficiency, and tool wear was researched with single factor test. The result indicated that the ratio of spindle speed and workpiece speed should be within a certain range in order to minimize tool wear, and tool wear increases with the increase of cutting depth, but not a linear relation.

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