Test Research on the Surface Residual Stress of Dimensional Ultrasonic Vibration Grinding for Al2O3/ZrO2(n)

2011 ◽  
Vol 295-297 ◽  
pp. 78-82
Author(s):  
Yan Wu ◽  
Er Geng Zhang ◽  
Wen Zhong Nie
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Ultrasonic Vibration ◽  
Ground Surface ◽  
Ductile Deformation ◽  
Grinding Wheel ◽  
Ceramic Surface ◽  
Two Dimensional ◽  
Surface Residual Stress ◽  
Xrd Diffraction

Based on the research for the structure of the ceramic nanocomposites’ intragranular for Al2O3/ZrO2(n)，we did the test by the workpiece two-dimensional vibration grinding(WTDUVG), and focus on analyzing the characteristic and the effect element of the two-dimensional ultrasonic vibration grinding ceramic surface residual stress by the XRD diffraction. The result show that ceramic dimensional ultrasonic vibration grinding surface tensile stress is less than the same conventional grinding (CG) surface under tensile stress; two-dimensional ultrasonic vibration grinding surface residual compressive stress than conventional ground surface residual stress under the same grinding. Material removal mechanism of the grinding nature of the surface residual stress, when the material removaled by ductile deformation, grinding surface equal residual stress; when the material removaled by brittle- ductile mixed mode, the grinding surface tensile stress reduced, because the fracture of the ground surface, tensile stress released. As a results, the grit size of grinding wheel, Grinding depth and workpiece mechanical properties are the main technology factors affected the nature and size of the residual stress of ground surface.

Research on Surface Residual Stress of Nano-Composite Ceramics under Multi-Frequency Ultrasonic Grinding and Dressing

2011 ◽  
Vol 487 ◽  
pp. 447-451 ◽  
Author(s):  
Bo Zhao ◽  
Jin Xue Xue ◽  
M.L. Zhao
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Ultrasonic Vibration ◽  
Residual Tensile Stress ◽  
Ceramic Surface ◽  
Composite Ceramics ◽  
Surface Residual Stress ◽  
Nano Composite ◽  
Ultrasonic Grinding ◽  
Grinding Conditions

The surface residual stress of nano-composite ceramics prepared by mixed coherence system and machined both in ordinary grinding(OG) and ultrasonic vibration grinding(TDUVG) respectively were described. Researches showed that the characteristics of residual stress on ceramic surface is affected by grinding load, ultrasonic vibration frequency and released stress induced by generation of cracks whose magnitude is affected by material removal mechanism. Whether in ordinary grinding or ultrasonic grinding, tangential residual stress (TRS) in X direction is tensile stress, and in Y direction is compressive stress. The surface residual tensile stress in ordinary grinding is larger than that in ultrasonic grinding with the same grinding conditions. The influences of multi-frequency on the residual stress are studied.

The Machined Surface Residual Stress of Nano-Ceramics with Two-Dimensional Ultrasonic Vibration Assisted Grinding

2010 ◽  
Vol 455 ◽  
pp. 637-642 ◽  
Author(s):  
X.Q. Zhang ◽  
Chong Yang Zhao ◽  
Bao Yu Du
Keyword(s):  
Residual Stress ◽  
Ultrasonic Vibration ◽  
Wear Particle ◽  
Surface Plastic Deformation ◽  
Work Piece ◽  
Surface Plastic ◽  
Two Dimensional ◽  
Surface Residual Stress ◽  
Machined Surface ◽  
Ultrasonic Grinding

Surface plastic deformation form and residual stress distribution of nano-ceramics machined by ordinary grinding and two-dimensional ultrasonic grinding respectively were investigated. The obtained results show that machined surface residual stress in the two grinding modes is extrusion stress, and it decreased with the increasing of grinding depth. But the decrease of residual stress under two-dimensional ultrasonic grinding is less than that under normal grinding. In addition, under the same grinding parameters, the surface residual stress on two-dimensional ultrasonic vibration grinding is larger than that on ordinary grinding, and if other parameters unchanged, it is increased with the increase of wear particle granularity in the two grinding modes. It is produced by the reason that ductile regime of ceramic grinding become larger under ultrasonic grinding, so that material is still removed by plastic form at great depth. Plastic removal mode will produce greater surface extrusion stress, so with the increasing of grinding depth, the decreasing of residual stress under two-dimensional ultrasonic vibration grinding is less than that under the normal grinding. At the same time, the regular separating between wear particle and work piece improves the heat emission condition, which is also one of the reasons that the surface residual stress under two-dimensional ultrasonic grinding is larger than that under ordinary grinding.

Experimental Temperature Studies on Two Dimensional Ultrasonic Vibration Grinding the Nano-ZrO2 Ceramics

2009 ◽  
Vol 416 ◽  
pp. 540-545
Author(s):  
Ping Yan Bian ◽  
Bo Zhao ◽  
Yu Li
Keyword(s):  
Surface Temperature ◽  
Ultrasonic Vibration ◽  
High Surface ◽  
Grinding Wheel ◽  
Grinding Temperature ◽  
Two Dimensional ◽  
Workpiece Surface ◽  
Grinding Parameters ◽  
Thermocouple Method ◽  
The Relationship

In processing of engineering ceramics materials with diamond grinding wheel, grinding heat is one of vital factors influencing workpiece surface quality. Grinding parameters have important influences on workpiece surface temperature distributions. Contrast experiments on grinding temperature of nanoZrO2 under common and two dimensional ultrasonic vibration grinding(TDUVG) were carried out in this paper by manual thermocouple method. The relationship between grinding parameters and grinding temperature was clarified through theoretical analysis and experiment confirmation. The research results show that with the increases of grinding depth, grinding speed, and decrease of working table speed, the workpiece’s surface temperature would heighten accordingly. Furthermore, comparing with high surface layer temperature in common grinding, which often results in grinding burn, TDUVG can reduce grinding temperature effectively.

High Efficient Mechanism of Material Removal in Two-Dimensional Ultrasonic Grinding from the Locus Perspective

2009 ◽  
Vol 416 ◽  
pp. 609-613
Author(s):  
Ming Li Zhao ◽  
Bo Zhao ◽  
Yu Qing Wang ◽  
Guo Fu Gao
Keyword(s):  
Ultrasonic Vibration ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Material Surface ◽  
Grinding Wheel ◽  
Two Dimensional ◽  
Abrasive Grains ◽  
Ultrasonic Grinding ◽  
High Efficient

Relative motion of single abrasive is analyzed for the different applied directions of longitudinal ultrasonic vibration, and its locus is simulated in the present paper. The research results show that the locus in two-dimensional ultrasonic vibration is only similar to that in y-direction, and both are close to sinusoid curves. The width of grooves scratched by abrasive grains y-direction (axial direction of grinding wheel) is two times of the vibration amplitude, and the material removal rate increases remarkably. In case of x-direction (tangential direction of grinding wheel) ultrasonic vibration, abrasive grains with periodic force impact material surface with high frequency vibration, which make material fracture removal easy. Therefore, the high efficiency essence of material removal in two-dimensional ultrasonic grinding is revealed in view of locus. In addition, according to the results of grinding experiments, under same conditions good surface quality can be obtained in two-dimensional ultrasonic grinding and material removal rate in common grinding is the lowest. Consequently it is further proved that the method of two-dimensional ultrasonic vibration grinding is an effective one for ceramic materials.

Application of Outer Surface Irradiated Laser Stress Improvement Process (L-SIP) to Pressurizer as Residual Stress Improvement Method for Alloy 600 PWSCC Mitigation

2008 ◽  
Author(s):  
Takeshi Ueda ◽  
Koji Okimura ◽  
Kazuhiro Wakabayashi ◽  
Takashi Akaba ◽  
Kazuhiko Kamo ◽  
...  
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Outer Surface ◽  
Alloy 600 ◽  
Surface Residual Stress ◽  
Steel Pipes ◽  
Inner Surface ◽  
Improvement Process ◽  
Improvement Method ◽  
Work Method

Improvement of residual stress is effective in a countermeasure to deal with the stress corrosion cracks in pipe welds. A irradiated laser stress improvement process (L-SIP) will be introduced as a method to improve residual stress inside steel pipes. This work method is to improve inner surface residual stress from tensile stress to compressive stress by irradiating laser beam around the welds of steel pipe and utilizing the temperature differences between inner and outer surface. Recently this method is applied to PWR pressurizer surge nozzle on TRUGA unit 2.

Residual Stress in GaAs Layer Grown on 4°-Off (100)Si by MBE

1987 ◽  
Vol 91 ◽  
Author(s):  
T. Yao ◽  
Y. Okada ◽  
H. Kawanami ◽  
S. Matsui ◽  
A. Imagawa ◽  
...  
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Gaas Layer ◽  
Residual Tensile Stress ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Misfit Stress ◽  
Si Substrates ◽  
Gaas Films ◽  
Semiconductor Laser Diodes

ABSTRACTResidual stress in molecular beam epitaxially (MBE) grown GaAs films on 4°-off (100)Si substrates is investigated with X-ray diffraction technique. It is experimentally confirmed that the GaAs lattice suffers tetragonal deformation with the c-axis being [100]. The GaAs lattice tilts by approximately 0.2° towards the tilted direction of the substrate. It is found that two-dimensional compressive stress dominates in GaAs films thinner than 0.3 μm in thickness, while two-dimensional tensile stress dominates in thicker films. The variation of the stress is understood in terms of a combination of misfit stress and thermal stress. The residual tensile stress is larger than 1 × 109 dyn/cm2 in the films thicker than I pm. The effect of the stress on the reliability of semiconductor laser diodes is discussed.

Experimental Study on Ultrasonic Vibration Dressing Wheel

2010 ◽  
Vol 135 ◽  
pp. 260-264
Author(s):  
Dao Hui Xiang ◽  
Xin Tao Zhi ◽  
Guang Xi Yue ◽  
Bo Zhao ◽  
Q.T. Fan
Keyword(s):  
Surface Quality ◽  
Ultrasonic Vibration ◽  
Ground Surface ◽  
Surface Characteristics ◽  
Axial Direction ◽  
Grinding Wheel ◽  
Workpiece Surface ◽  
Surface Burn ◽  
Grinding Conditions ◽  
Strict Requirement

Excellent wheel dressing technology can ensure the ground surface quality effectively. Because precision machining has a strict requirement on the wheel dressing, the wheel dressing with ultrasonic vibration was adopted, and the device of ultrasonic vibration dressing was also designed in this paper. On the base of analysis mechanism of ultrasonic vibration dressing wheel, the grinding experiment was carried out in different dressing conditions. The surface characteristics of ultrasonic dressing wheel and the influence of different dressing parameters on the workpiece surface quality were studied. Furthermore, the optimal dressing parameters have been obtained. The experiment results indicate that the micro cutting edge of grinding wheel distribute sparsely in circumferential directional but densely in axial direction in the condition of ultrasonic dressing, and it is particular characteristic of ultrasonic dressing. When the dressing and grinding conditions are suitable, the workpiece surface roughness can be reduced, but the conditions are not arbitrary. At the same time, the workpiece surface burn can be effectively reduced, even if the larger grinding depth is used during the grinding process.

Investigation on the Workpiece Surface Residual Stress in High Efficiency Deep Grinding with Ultra High Wheel Speeds

2011 ◽  
Vol 487 ◽  
pp. 24-28
Author(s):  
Tan Jin ◽  
D.J. Stephenson ◽  
X.M. Sheng
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Contact Time ◽  
High Efficiency ◽  
Ground Surface ◽  
Grinding Process ◽  
Combined Effects ◽  
Surface Residual Stress ◽  
Workpiece Surface ◽  
Short Contact Time

The residual stress on the ground surface of workpiece in high efficiency deep grinding (HEDG) has been investigated. It has been found that the mechanism in forming the ground surface residual stress in HEDG is much different to that in the conventional shallow cut grinding process. It is not a thermally dominant event as in most of the shallow cut grinding mode; it is instead driven by the combined effects of both the thermal and mechanical loadings. The compressive plastic deformation near the workpiece surface during grinding and the short contact time in the HEDG regime, makes it possible to generate compressive surface stresses even when the surface temperatures are above 700-800°C.

Research on Surface Residual Stress of Nano-ZrO2 Ceramic After Ultrasonic Vibration Grinding

2012 ◽  
Vol 12 (1) ◽  
pp. 294-298
Author(s):  
Bo Zhao ◽  
Guoyuan Ren ◽  
Jianguo Yao ◽  
Zhenfeng Jia
Keyword(s):  
Residual Stress ◽  
Ultrasonic Vibration ◽  
Surface Residual Stress

Research on Micro Characteristics of Surface and Subsurface Layer in Two-Dimensional Ultrasonic Grinding Nano-Composite Ceramics

2008 ◽  
Vol 375-376 ◽  
pp. 395-400 ◽  
Author(s):  
Bo Zhao ◽  
Guo Fu Gao ◽  
Yan Wu ◽  
Feng Jiao
Keyword(s):  
Ultrasonic Vibration ◽  
Fracture Behavior ◽  
Lattice Distortion ◽  
Ground Surface ◽  
Nano Materials ◽  
Two Dimensional ◽  
Composite Ceramics ◽  
Nano Composite ◽  
Ultrasonic Grinding ◽  
Deformation Layer

This work mainly studied the deterioration layer structure, crystal grain size, crystal lattice distortion of ground surface in two-dimensional ultrasonic vibration grinding nano-composite ceramics. The research indicated that under a certain grinding condition the ductile deformation layer on the ground surface of nano-composite ceramics in two-dimensional ultrasonic vibration grinding is formed by the ways of material powdering, crystal grain fragmentation, materials extrusion, the crystal grain pull-off and so on. The transition layer between the surface layer and the base body is plastic deformation layer by the primarily ways of crystal lattice distortion and the crystal boundary slipping. The removed material in brittleness fracture mode is extremely few. In this work, the structural model of deterioration layer on ground surface in two-dimensional ultrasonic grinding nano-composite ceramics is put forward. The microscopic deformation mechanism of nano materials is inner grain dislocation of inner-grain-structure strengthened phase. Its deformation coordination mechanism is the the grain-boundary sliding of matrix grain and the coordinated deformation of intercrystalline second-phase. The TEM and SEM observation discovers that the nano particles dispersed in grain boundary stops crack from expanding in nano materials, which causes the materials to appear in transcrystalline fracture behavior. And this fracture behavior gives materials favorable finished surface. The plastic deformation is the dominant removal mechanism of the nano materials in two-dimensional ultrasonic vibration grinding.

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