scholarly journals THE EFFECT OF ABRASIVE GRAIN SHAPES ON QUALITY OF FERRITE MAGNETS GRINDING PROCESS

2020 ◽  
Vol 14 (2) ◽  
pp. 117-124
Author(s):  
Bayu Rahmat Saputro ◽  
Amin Suhadi

Abstract A research was conducted on the grinding process of ferrite magnet with Strontium ferrite type (SrO.6 (Fe2O3)) using electroplated single layer grinding wheels. Many cracks have been found on work pieces during this work, which is coming from grinding processes. Research is conducted starting from chemical composition test and the effect of the shape and size of the abrasive grain of grinding wheels to the quality of grinding process results by measuring crack ratio of the work piece.  In this experiment, 3 (three) model design of grinding wheels with three different size and shape of abrasive grains are made. All of processing parameters are set at the same value as ordinary process.  The experimental results shown that 3rd model have the best results from the outputs number and also the lowest reject crack ratio compared to 1st and 2nd models. This is because the 3rd model has blocky shape which its distribution structure is denser and more uniform compared to the irregular shape, so that continuous grinding on hard and brittle work pieces is more stable and suitable

10.14311/1598 ◽  
2012 ◽  
Vol 52 (4) ◽  
Author(s):  
Ondrej Jusko

This paper focuses on the influence of various types of abrasive grains on cutting properties during the grinding process for bearing steel. In this experiment, not only conventional super-hard abrasive materials but also a new type of abrasive material were employed in grinding wheels. The measurement results were compared, and an evaluation was made of the cutting properties of the new abrasive material. The options were then evaluated for their practical applicability. The measurement results indicated that a grinding wheel with Abral and SG grains is the most suitable for grinding hardened bearing steel in order to achieve the best roughness and geometrical accuracy.


2019 ◽  
Vol 297 ◽  
pp. 09002
Author(s):  
Vyacheslav Shumyacher ◽  
Sergey Kryukov ◽  
Olga Kulik ◽  
Xavier Kennedy

The mechanism of chip formation process at grinding is described, which involves a high-speed interaction of abrasive grain and metal, which leads to a concentration of thermal energy in front of the dispersing element (grain), causing a locally concentrated shift in the metal microvolume. In “abrasive grain -metal” contact a dissipative structure is formed which existence is supported by exchange of energy and substance with environment. Due to shock compression of the metal microvolume with abrasive grain, shock-wave heating is realized, initiating emission of electrons ionizing the lubricating cooling fluid in the zone of formation of side micro-scratches left by abrasive. The results obtained in the course of the research can be used to explain the mechanisms of chip formation, as well as the course of the physical and mechanical processes occurring on the surface layers of the grinded workpieces. By controlling chip formation processes at high-speed grinding, by optimally selecting the appropriate ratios between cutting speed and other processing parameters, a reduction in process thermal density can be achieved, which, with the highest productivity, will allow to obtain the required quality of the surface layer of the workpieces and a given dimensional accuracy.


2021 ◽  
Vol 1199 (1) ◽  
pp. 012053
Author(s):  
D Łączny ◽  
M Macko ◽  
K Moraczewski ◽  
J Lewandowski

Abstract The paper presents a comparative analysis of the effect of selected design features of blade and disc units on the functional characteristics of the process of grinding corn stalks in specific ranges of input variables. The effect of changes in the geometric features of the working units and rotational speeds on the energy demand during the grinding process was estimated. On this basis, an assessment of the quality of the shredding product in terms of shape and size was also made.


2011 ◽  
Vol 189-193 ◽  
pp. 3668-3671 ◽  
Author(s):  
Qing Song Wei ◽  
Xiao Zhao ◽  
Li Wang ◽  
Rui Di Li ◽  
Jie Liu ◽  
...  

Selective Laser Melting (SLM) can produce high-performance metal parts with complex structures. However, it’s difficult to control the processing parameters, because many factors involves. From the perspective of the molten pool, the study focuses on the effects of processing parameters, including scanning speed, laser power, scanning space, layer thickness, and scanning strategies, on the surface quality, the balling effect, the density of SLM parts, by conducting experiments of single track, single layer and block forming. The results show that the quality of the molten pool is affected by laser power and scanning speed. Scanning drove in the strategy of “jumping and turning”,a smooth surface and a less balling effect will be obtained. The thicker the powder layer is, the lower density will be obtained. The optimal parameters from series of experiments are: laser power of 98W; scanning speed of 90mm/s; scanning space of 0.07mm; layer thickness of 0.1mm; and scanning strategy of “jumping and turning”.


2012 ◽  
Vol 2 (3) ◽  
Author(s):  
Krzysztof Nadolny

AbstractThis article presents the method of comparative assessment of the grinding wheel cutting ability in the plunge grinding kinematics. A new method has been developed to facilitate multicriterial assessment of the working conditions of the abrasive grains and the bond bridges, as well as the wear mechanisms of the GWAS, which occur during the grinding process, with simultaneous limitation of the workshop tests range. The work hereby describes the methodology of assessment of the grinding wheel cutting ability in a short grinding test that lasts for 3 seconds, for example, with a specially shaped grinding wheel, in plunge grinding. The grinding wheel macrogeometry modification applied in the developed method consists in forming a cone or a few zones of various diameters on its surface in the dressing cut. It presents an exemplary application of two variants of the method in the internal cylindrical plunge grinding, in 100Cr6 steel. Grinding wheels with microcrystalline corundum grains and ceramic bond underwent assessment. Analysis of the registered machining results showed greater efficacy of the method of cutting using a grinding wheel with zones of various diameters. The method allows for comparative tests upon different grinding wheels, with various grinding parameters and different machined materials.


Author(s):  
Taghi Tawakoli ◽  
Abdolreza Rasifard ◽  
Alireza Vesali

The efficiency of the grinding process highly depends on the coolant lubricant used. In grinding with CBN grinding wheels grinding oils are used increasingly. In the last decade new grinding oils based on different oil types are brought into the market, whose effect on the CBN grinding wheels performance until now not sufficiently been investigated. The Institute of Grinding and Precision Technology (KSF) investigated the influence of four different grinding oils on the performance of vitrified CBN grinding while grinding of 100Cr6 (M.-No. 1.3505), which is a heat-treatable steel with a very good grindability, and Nimonic A80, which is a difficult to grind heat-resistance superalloy. The obtained results show that the performance of the vitrified CBN grinding wheels—while using grinding oil as coolant lubricant—regarding the quality of the work piece surface, the grinding forces as well as the wear of the grinding wheel, highly depend on the viscosity of the grinding oil. Moreover, the results show that the surface quality and the grinding forces while using different grinding oils depend significantly on the work piece material.


2016 ◽  
Vol 23 (4) ◽  
pp. 567-577 ◽  
Author(s):  
Dariusz Lipiński ◽  
Wojciech Kacalak

Abstract Analysis of the shape and location of abrasive grain tips as well as their changes during the grinding process, is the basis for forecasting the machining process results. This paper presents a methodology of using the watershed segmentation in identifying abrasive grains on the abrasive tool active surface. Some abrasive grain tips were selected to minimize the errors of detecting many tips on a single abrasive grain. The abrasive grains, singled out as a result of the watershed segmentation, were then analyzed to determine their geometric parameters. Moreover, the statistical parameters describing their locations on the abrasive tool active surface and the parameters characterizing intergranular spaces were determined.


2019 ◽  
Vol 13 (6) ◽  
pp. 722-727
Author(s):  
Takekazu Sawa ◽  

Grinding is difficult to control because abrasive grains are scattered randomly on the surface of the grinding wheel, and the quality of the grinding work is strongly dependent on the skill of the operator. Therefore, automation and optimization technologies should be established immediately for grinding, along with other machining work. From this perspective, we observed the bending vibrations of a diamond wheel during a grinding project and developed a technique to identify the grinding condition by using a microphone to measure the small noises from the vibration (called bending-vibration noise in this paper). In this paper, we report the application of the technique to an ordinary grinding wheel, and our attempt to automate the grinding work of STAVAX and SKD11 metal materials.


2009 ◽  
Vol 416 ◽  
pp. 259-263
Author(s):  
Heng Hua Zhao ◽  
Chong Su

Grinding is one of the most extensive manufacture technics. Grinding process becomes very complex and difficult to analyze, because the distribution of abrasive grains is stochastic and abrasive grain geometrical shape is anomalistic. So the research on grinding locomotion gets into corner. The application of computer simulation in grinding process can availably analyze the effect brought by many complicated factors in the process. So the paper advances some suppositions and simulates the process based on AutoCAD & AutoLISP. An equation of process track is educed .The simulation makes the grinding process become intuitionistic. It is also very useful to the analysis of grinding.


2019 ◽  
Vol 799 ◽  
pp. 43-51
Author(s):  
Margarita Urbaha ◽  
Svetlana Bogdanova ◽  
Alexanders Urbahs

One of the most efficient methods of improving the durability of a product is applying different coatings to the working surface. The quality of decorative and protective coatings is determined by the quality of workpiece surface (roughness, texture, etc.), preparation of workpiece surface (contamination, presence of oxide films, degree of surface activation by ion etching), and the production methods. The article presents the results of a series of experiments in creating multi-component ion-plasma coatings by vacuum deposition on Ti-Al basis. A series of experiments aimed at obtaining single-layer coatings have been carried out using a certain pattern of sputtering in argon and nitrogen environment. The obtained coatings can have a wide variety of colors. Different properties of the created coatings including spectral characteristics, reflection coefficient at different angles of incidence of light as well as chemical composition have been studied. The energy-dispersive electron microprobe analysis revealed the dependence of coating reflection coefficient and spectral characteristics on the chemical composition.


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