scholarly journals Analysis of Grinding Surface Creation by Single-Grit Approach

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
X. Chen ◽  
T. T. Öpöz ◽  
A. Oluwajobi
Keyword(s):  
Material Removal ◽  
Ground Surface ◽  
Element Model ◽  
Surface Formation ◽  
Grinding Conditions ◽  
Research Findings ◽  
Kinetic Condition ◽  
The Difference ◽  
New Research ◽  
Grinding Efficiency

This paper presents some new research findings in the investigation of single-grit grinding in terms of surface creation. The investigation demonstrated that rubbing–plowing–cutting hypothesis of grinding material removal mechanism is valid in both experiments and simulations. A finite element model (FEM) was developed to simulate the material deformation during the grit interacts with the workpiece. It was found that the cutting mechanism is the more effective in the first half of the scratch where the grit penetrates the workpiece. The plowing is a prominent mechanism in the second half of the scratch where the grit is climbing up along the scratch path and uplifting the material at the front and the sides of it. This observation is very important to provide a greater insight into the difference between up-cut and down-cut grinding material removal mechanisms. Multipasses scratch simulations were performed to demonstrate the influence of plowing on the ground surface formation. Moreover, by analyzing the effects of grinding conditions, the shape of cutting edges, and friction in grinding zone on the grinding surface formation, some useful relations between grinding performance and controllable parameters have been identified. It has demonstrated that plowing has significant influences on ground surface formation and concluded that the influence of grit shape, friction, and grinding kinetic condition should be considered together for the plowing behavior control, which could provide a good guidance for the improvement of grinding efficiency.

Comparative Study on the Materials Removal Mechanism of Ceramics and Steels

2008 ◽  
Vol 389-390 ◽  
pp. 18-23
Author(s):  
Jian Qiang Guo ◽  
Hitoshi Ohmori ◽  
Kazutoshi Katahira ◽  
Yoshihiro Uehara
Keyword(s):  
Comparative Study ◽  
Material Removal ◽  
Ground Surface ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Grinding Forces ◽  
Dressing Method ◽  
The Difference ◽  
Induced Defects

Ceramics has many advantages that cannot be substituted by metals, but its machining induced defects, such as crack and crater, are the obstacle of using ceramics in engineering. Thus, the further studies on the materials removal mechanism of ceramics should be done. As known, the cutting theory of metals is very successful and it is helpful to understand the material removal mechanism of ceramics. Through doing comparative experiments, the material removal mechanism of ceramics may be more deeply ascertained. Four types of material, such as ZrO2, SiC, STAVAX and SKD11, were ground by ELID (ELectrolytic In-process Dressing) method in this study. The grinding forces, roughness and topography of the ground surface were investigated. On the basis of this experiment, the difference of material removal mechanism between ceramics and steels was explained.

A Preliminary Study of Surface Integrity and Wheel Wear in the Grinding of Multilayered Thin Film Structures

2014 ◽  
Vol 1017 ◽  
pp. 88-91
Author(s):  
Cheng Wei Kang ◽  
Bing Jun Hao ◽  
Han Huang
Keyword(s):  
Thin Film ◽  
Surface Finish ◽  
Material Removal ◽  
Removal Rate ◽  
Ground Surface ◽  
Depth Of Cut ◽  
Wheel Wear ◽  
Multilayered Thin Film ◽  
Pull Out ◽  
Grinding Conditions

This study aimed to investigate the effect of grinding conditions, including depth of cut and grinding direction, on the material removal and surface finish of multilayered thin film structures. It was found that the increase in depth of cut improved the material removal rate, but worsened the ground surface finish. The grinding perpendicular to the thin films caused less damage and produced better surface than that parallel to the films. The characteristics of wheel wear were also studied. Grit pull-out and micro-fracture should be attributed to the wheel wear.

Employee engagement: New research findings, directions, and questions

2007 ◽  
Author(s):  
Amy Colbert ◽  
Bruce Louis Rich ◽  
Timothy A. Judge
Keyword(s):  
Employee Engagement ◽  
Research Findings ◽  
New Research

A New Narrative?

2018 ◽  
Author(s):  
Natalia Nowakowska
Keyword(s):  
Master Narratives ◽  
European Context ◽  
Early Signs ◽  
Research Findings ◽  
New Research ◽  
The Impact ◽  
Different Sources

Our three existing master narratives of the early Reformation in Poland are all over a century old and mutually contradictory, drawing on different sources to serve differing confessional and national/ist agendas. This chapter offers a fresh narrative of the impact of Lutheranism on the Polish composite monarchy to c.1540, synthesizing these older accounts and updating them with new research findings. This is a narrative in three parts: early signs (1517–24), the great Reformation year (1525), and aftershocks (1526–40). The chapter discusses the challenges of measuring ‘Lutheran’ sentiment, sets these Polish-Prussian events clearly in their comparative European context, and considers what implications they might have for that bigger, familiar tale. It stresses the precocity of Sigismund I’s monarchy, which saw the most far-reaching urban and violent Reformation in 1520s Europe (Danzig), a peasant Reformation rising, and Christendom’s first territorial-princely Reformation, in Ducal Prussia.

scholarly journals Study on the Effect of Grinding Pressure on Material Removal Behavior Performed on a Self-Designed Passive Grinding Simulator

2021 ◽  
Vol 11 (9) ◽  
pp. 4128
Author(s):  
Peng-Zhan Liu ◽  
Wen-Jun Zou ◽  
Jin Peng ◽  
Xu-Dong Song ◽  
Fu-Ren Xiao
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Service Life ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Temperature ◽  
Grinding Efficiency

Passive grinding is a new rail grinding strategy. In this work, the influence of grinding pressure on the removal behaviors of rail material in passive grinding was investigated by using a self-designed passive grinding simulator. Meanwhile, the surface morphology of the rail and grinding wheel were observed, and the grinding force and temperature were measured during the experiment. Results show that the increase of grinding pressure leads to the rise of rail removal rate, i.e., grinding efficiency, surface roughness, residual stress, grinding force and grinding temperature. Inversely, the enhancement of grinding pressure and grinding force will reduce the grinding ratio, which indicates that service life of grinding wheel decreases. The debris presents dissimilar morphology under different grinding pressure, which reflects the distinction in grinding process. Therefore, for rail passive grinding, the appropriate grinding pressure should be selected to balance the grinding quality and the use of grinding wheel.

scholarly journals Comparative analysis of sports consumption habits in Hungary, Poland and Germany

2021 ◽  
Vol 21 (S1) ◽  
Author(s):  
Dávid Paár ◽  
Antal Kovács ◽  
Miklós Stocker ◽  
Márk Hoffbauer ◽  
Attila Fazekas ◽  
...  
Keyword(s):  
Physical Activity ◽  
Material Wealth ◽  
Important Indicator ◽  
Sports Clubs ◽  
Research Findings ◽  
Study Population ◽  
Sports Consumption ◽  
The Difference ◽  
Sports Venues ◽  
The Relationship

Abstract Background The so-called sports consumption models are looking for the factors that influence the sports spending of households. This paper aims to examine the Hungarian, Polish and German households’ sports expenditures which can be an important indicator of physical activity and sporty lifestyle. Methods Surveying of households in three countries (Hungary, Poland and Germany) has been conducted with a self-designed questionnaire. We have used descriptive and bivariate non-parametric and parametric statistical methods: (1) χ2 test, Mann-Whitney test and Kruskal-Wallis test for checking the relationship between sociodemographic and physical activity variables and (2) independent sample t-test and ANOVA for checking the differences in sports expenditures. Results Our research concluded that men, especially previous athletes, exercise more than women and those who have no history as registered athletes. The choice of sports venues is obviously different between the countries in the sample. Members of the study population spend the most on sports services while they spend the least on sports equipment. German households have the highest spending rates compared to the other two countries. Conclusions Results are in line with our previous research findings and with other literatures. The difference in preferences of sports venues could have the reason of different supply of sports clubs or the different living standards too. It needs further researches to clear it. Material wealth, income level and sport socialisation can be a determining factor regarding the level of sports spending.

scholarly journals Avian Bornaviral Ganglioneuritis: Current Debates and Unanswered Questions

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Su L. Boatright-Horowitz
Keyword(s):  
Best Practices ◽  
Wasting Disease ◽  
Avian Virus ◽  
Research Findings ◽  
New Research

Avian bornaviral ganglioneuritis, often referred to as parrot wasting disease, is associated with a newly discovered avian virus from the taxonomic family Bornaviridae. Research regarding the pathogenesis and treatment for this disease is ongoing, with implications for understanding other emerging human and nonhuman diseases, as well as the health and ecology of wildlife. At this time, numerous questions remain unanswered regarding the transmission of the disease, best practices for diagnostic sampling and testing, and whether currently used drug therapies are effective or harmful for afflicted birds. The pathogenesis of the disease also remains unclear with many birds showing resistance to the effects of the virus and being able to remain clinically unaffected for years, while other birds succumb to its effects. New research findings regarding avian bornaviral ganglioneuritis are discussed and important as yet unanswered questions are identified.

Microgrinding of Nanostructured Carbide Coatings: Ground Surface and Subsurface Damage Observations

2006 ◽  
Vol 304-305 ◽  
pp. 276-280 ◽  
Author(s):  
Y.H. Ren ◽  
Zhi Xiong Zhou ◽  
Zhao Hui Deng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Material Removal ◽  
Ground Surface ◽  
Subsurface Damage ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Carbide Coatings ◽  
Subsurface Layers ◽  
Scanning Electron

Surface microgrinding of the nanostructured WC/12Co coatings have been undertaken with diamond wheels under various conditions. Nondestructive and destructive approaches were utilized to assess damage in ground nanostructured coatings. Different surface and subsurface configurations were observed by scanning electron microscopy. This paper investigates the effects of microgrinding conditions on damage formation in the surface and subsurface layers of the ground nanostructured WC/12Co coatings. And the material-removal mechanism has been discussed.

Study on the Behavior of the Cast-Iron Bonded Grinding Wheel to Machining Properties of Hard and Brittle Materials

2007 ◽  
Vol 24-25 ◽  
pp. 229-232
Author(s):  
S.L. Ma ◽  
Wei Li ◽  
Cong Rong Zhu ◽  
J. Zhang ◽  
H.C. Ye
Keyword(s):  
Grain Size ◽  
Cast Iron ◽  
Tungsten Carbide ◽  
Surface Quality ◽  
Ground Surface ◽  
Grinding Wheel ◽  
Different Grain Size ◽  
Grinding Efficiency ◽  
Machining Properties

Tungsten carbide which is a hard and brittle material was ground by cast-iron bonded diamond wheel with ELID (Electrolytic In-Process Dressing) technique, for the purpose of getting high efficiency, super-precision machining. Three kinds of cast-iron bonded diamond wheels with different grain size were adopted to get different grinding efficiency and surface quality of workpieces. The grinding properties of cast-iron bonded grinding wheels with different grain size and the ground surface quality of tungsten carbide are discussed in this paper. The experiment results indicate that, under the same feeding amount, the grinding efficiency of the wheel with bigger grain size is higher, and it could make the dimension accuracy of the workpiece controllable, but the wheel with smaller grain size could get better ground surface quality. The two grinding phases are decided by the ratio between the size of abrasive grain and the thickness of the oxide layer on the grinding wheel.

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