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.

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 Roughness and Micro-Topography of Nano-ZrO2 Plate in Two-Dimension Ultrasonic Grinding

2008 ◽  
Vol 53-54 ◽  
pp. 243-247 ◽  
Author(s):  
Bo Zhao ◽  
Ming Li Zhao ◽  
Guo Fu Gao
Keyword(s):  
Surface Roughness ◽  
Ultrasonic Vibration ◽  
Ceramic Materials ◽  
Ceramic Plate ◽  
Two Dimensional ◽  
Machined Surface ◽  
Ultrasonic Grinding ◽  
High Efficient ◽  
Micro Topography ◽  
Processing Difficulty

The influence of ultrasonic vibration on the surface roughness and micro-topography of ceramics plate is discussed in this paper. Grinding assisted by two-dimensional ultrasonic vibration is developed to deal with the processing difficulty of ceramic materials due to its hard-brittle property. The experimental results show that the surface roughness value obtained in two-dimensional ultrasonic grinding nano-ZrO2 ceramic plate specimen is obviously smaller than that in common grinding, and the scratched grooves on the machined surface in ultrasonic grinding is wider and relatively smoother than that in common grinding. Consequently, it proves that the two-dimensional ultrasonic machining is a feasible, high-efficient machining method for hard-brittle materials.

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.

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 Influence of Stretched Fixation on Face Milling-Machined 6061T6 Aluminum Alloy

2013 ◽  
Vol 589-590 ◽  
pp. 264-268 ◽  
Author(s):  
Wei Yi ◽  
Zhao Liang Jiang ◽  
Zhi Li ◽  
Bin Li ◽  
Wen Ping Liu
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Surface Topography ◽  
Face Milling ◽  
Work Piece ◽  
Machining Parameters ◽  
Surface Residual Stress ◽  
Machined Surface ◽  
Surface Flatness ◽  
The Face

The influence of stretched fixation on face milling-machined 6061T6 aluminum alloy, a widely used material in industry, was investigated in the paper. A unidirectional stretched fixture was designed and used in the face milling experiments. During the experiments, the pre-stress exerted on the work-piece increased from 0 to 220MPa with other machining parameters being constant. Surface topography, surface residual stress and flatness were measured. The results reveal that stretched fixation has significantly effect on residual stress, machined surface flatness, and roughness.

INVESTIGATION OF THE PROCESS OF RESTORATION OF DAMAGED PIPELINE SURFACES BY THE METHOD OF SURFACE RIVETING

2021 ◽  
pp. 126-132
Author(s):  
О.В. Уразов ◽  
А.Д. Данилов
Keyword(s):  
Residual Stress ◽  
Work Hardening ◽  
Experimental Studies ◽  
Surface Plastic Deformation ◽  
Numerical Control ◽  
Surface Plastic ◽  
Machined Surface ◽  
Surface Work ◽  
Stress Components ◽  
Industrial Unit

Представлены результаты экспериментальных исследований процесса восстановления поврежденных поверхностей трубопроводов различных диаметров методом поверхностного наклепа, реализующего явление поверхностного пластического деформирования, приводящее к изменению распределения напряжений по толщине, выполнено обоснование оптимальных режимов его проведения . При этом было осуществлено численное моделирование процесса накатки, определены оптимальные значения следующих параметров: глубины и силы ППД, скорости ППД, подачи ролика, формы рабочей поверхности используемого ролика. При анализе были учтены следующие физико-механические характеристики: глубина наклепа, величина остаточных напряжений, глубина распределения остаточных напряжений, время обкатки, нагрузка на ролик. Доказано очевидное преимущество роликов большего радиуса профиля - они позволяют обеспечить необходимое изменение шероховатости обрабатываемой поверхности при обкатке с большей подачей, что приводит к снижению времени технологического процесса. При этом в принятом диапазоне параметров режимов обкатки (нагрузка 2500÷3000Н, глубина вдавливания 0.04÷0.06мм) величины компонентов остаточных напряжений оказались практически идентичными для исследованных режимов всех рассмотренных роликов. Полученные результаты были положены в основу технологии восстановительного ремонта трубопроводов различного диаметра без остановки производственного процесса на Нововоронежской АЭС и создана промышленная установка с числовым программным управлением для реализации данной технологии Here we present the results of experimental studies of the process of restoration of damaged surfaces of pipelines of various diameters by the method of surface work hardening, which implements the phenomenon of surface plastic deformation, leading to a change in the distribution of stresses along the thickness. At the same time, we carried out a numerical simulation of the knurling process, we determined the optimal values of the following parameters: the depth and strength of the SPD, the speed of the SPD, the feed of the roller, the shape of the working surface of the roller used. The analysis took into account the following physical and mechanical characteristics: work hardening depth, residual stress value, residual stress distribution depth, running time, roller load. We proved the obvious advantage of rollers with a larger profile radius - they allow one to provide the necessary change in the roughness of the machined surface during rolling with a higher feed, which leads to a decrease in the time of the technological process. In this case, in the accepted range of parameters of the running modes (load 2500-3000N, indentation depth 0.04-0.06 mm), the values of the residual stress components turned out to be almost identical for the considered modes for all the considered rollers. We used the results as the basis for the technology of restorative repair of pipelines of various diameters without stopping the production process at the Novovoronezh NPP and an industrial unit with numerical control was created to implement this technology

Plastic deformation of collector plates at electric motor repair

2020 ◽  
pp. 79-82
Author(s):  
D.YU. Belan ◽  
G.B. Toder ◽  
K.V. Averkov ◽  
YU.V. Titov
Keyword(s):  
Plastic Deformation ◽  
Electric Motor ◽  
Roughness Parameter ◽  
Surface Plastic Deformation ◽  
Analytical Dependence ◽  
Surface Plastic ◽  
Machined Surface ◽  
Tool Surface ◽  
Diamond Burnishing ◽  
Traction Electric Motor

A tool was developed for smoothing the plates of an electric motor collector. An analytical dependence of the roughness parameter of the machined surface on the force applied to the tool is obtained. Keywords traction electric motor, collector, diamond burnishing tool, surface-plastic deformation, repair, roughness. [email protected]

Study on Grinding Force in Two-Dimensional Ultrasonic Grinding Nano-Ceramics

2010 ◽  
Vol 42 ◽  
pp. 204-208 ◽  
Author(s):  
Xiang Dong Li ◽  
Quan Cai Wang
Keyword(s):  
Mathematical Model ◽  
Ultrasonic Vibration ◽  
Contact Time ◽  
Reaction Force ◽  
Grinding Force ◽  
Two Dimensional ◽  
Indentation Fracture ◽  
Ultrasonic Grinding ◽  
The Impact ◽  
Ultrasonic Vibration Assisted Grinding

In this paper, the characteristic of grinding force in two-dimensional ultrasonic vibration assisted grinding nano-ceramic was studied by experiment based on indentation fracture mechanics, and mathematical model of grinding force was established. The study shows that grinding force mainly result from the impact of the grains on the workpiece in ultrasonic grinding, and the pulse power is much larger than normal grinding force. The ultrasonic vibration frequency is so high and the contact time of grains with the workpiece is so short that the pulse force will be balanced by reaction force from workpiece. In grinding workpiece was loaded by the periodical stress field, which accelerates the fatigue fracture.

Effect of Milling Speed and Feed on Surface Residual Stress of 7050-T7451 Aluminum Alloy

2012 ◽  
Vol 499 ◽  
pp. 217-222 ◽  
Author(s):  
C. Li ◽  
Yi Wan ◽  
R.R. Zhang ◽  
Zhan Qiang Liu
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Cutting Speed ◽  
Diffraction Method ◽  
Cutting Condition ◽  
Feed Speed ◽  
X Ray Diffraction ◽  
Surface Residual Stress ◽  
Orthogonal Direction ◽  
Machined Surface

The residual stress in the milling of 7050-T7451 aluminum alloy was measured using X-ray diffraction method in which Psi-oscillation, Phi-oscillation and peak fit were adopted. Cutting speed and feed are main variables which were considered in this study. The results show that compressive residual stresses are generated in surface for the down milling generally, which is mainly due to burnishing effect between the tools flank face and the machined surface. In feed and its orthogonal direction, the effect of cutting speed and feed speed on residual stress is similar. Therefore, required residual stress can be achieved by controlling the cutting condition such as cutting speed, feed speed etc.

Influence of Cutting Speed on Surface Plastic Deformation and White Layer Formation of FGH95

2013 ◽  
Vol 589-590 ◽  
pp. 70-75 ◽  
Author(s):  
Jin Du ◽  
Zhan Qiang Liu
Keyword(s):  
Plastic Deformation ◽  
Surface Integrity ◽  
White Layer ◽  
High Reliability ◽  
Cutting Speed ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Layer Formation ◽  
Machined Surface ◽  
White Layer Formation

The superalloy parts in the aeronautical field demand high reliability, which is largely related to surface integrity. Surface integrity generally includes three parameters, such as geometric parameter, mechanical parameter and metallurgical parameter. The paper presents the influence of cutting speed on surface plastic deformation and white layer formation through orthogonal milling of FGH95 superally material. The influence of cutting speed on grain refinement of machined surface is also investigated. It is found that cutting speed has significantly effect on the surface metallurgical characteristic microstructure. The increasing of cutting speed creates severer plastic deformation. Surface plastic shear strain increases with the increasing of cutting speed, while the depth of plastic deformation decreases on contrary. White layer thickness is increased with the increasing of cutting speed. Through statistical analysis for grains number, it can be drawn that the higher the cutting speed, the more serious grains refinement.

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