scholarly journals INFLUENCE OF EDM WORN SURFACE OF THE WORKING PART OF STEEL BORON TOOTH TO RESTORE ITS CUTTING ABILITY

2017 ◽  
Vol 16 (3) ◽  
pp. 189-195
Author(s):  
M. G. KiselevG. ◽  
P. S. Bohdan ◽  
M. M. Kryshnev ◽  
V. P. Semenkovich
Keyword(s):  
Surface Modification ◽  
Electrical Discharge Machining ◽  
Computing Time ◽  
Experimental Studies ◽  
Storage Capacitor ◽  
Basic Information ◽  
Working Surface ◽  
Cylindrical Working ◽  
Modified Surface ◽  
Worn Surface

The article is devoted to the experimental evaluation of the efficacy of electrical discharge machining (modification) worn cylindrical working surface of the steel of boron in order to restore its cutting ability. It provides basic informationabout steel dental forests, including their structure and the main stages of production. It is noted that for such resource hog maximum computing time is about 9 minutes and then further worn drills are used and recycled. Based on an analysis of previous studies on the use of EDM surface modification of the wire, tape and disk recovery tools grounded prospect worn cutting ability of the working surface of the steel by its boron EDM with a view to its use in dental practice as well as in the production of dental products. Provides basic information about how to conduct experimental studies, including a description of the device for modifying the EDM worn working surface boron, as well as the device to determine its cutting ability on the intensity of cutting them a sample of the PCB. It was established experimentally that the resulting EDM modifying worn working surface boron therein forming wells having on the edges of the metal beading beyond the original contour of the surface, the height of which increases as the process of modifying U voltages on the storage capacitor, which leads to an increase in surface finish diameter boron. It has been shown that these spatter justified regarded as a kind of cutting elements (teeth) on the modified surface of the boron, giving it a worn surface of the cutting ability. It was established experimentally that the spark erosion boron worn surface modification can restore its cutting performance with respect to the original when U = 75 to 33.3%, and when U = 120 V - 43%, indicating a relatively high recovery efficiency of the proposed method of cutting the ability of the worn surface of steel dental burs.

scholarly journals Influence of Electro-Erosive Modification Modes for Worn Working Surface of Dental Cutters on Restoration of its Cutting Ability

2020 ◽  
Vol 19 (4) ◽  
pp. 288-296
Author(s):  
M. G. Kiselev ◽  
S. G. Monich ◽  
P. S. Bogdan ◽  
D. L. Korchigin ◽  
V. V. Efimenko
Keyword(s):  
Experimental Data ◽  
Electric Discharge ◽  
Storage Capacitor ◽  
Initial Contour ◽  
Basic Information ◽  
Experimental Assessment ◽  
Working Surface ◽  
Modified Surface ◽  
Worn Surface

An experimental assessment has been made of the influence of electro-erosive modification modes for worn working surface of an cutter on the restoration of its cutting ability. The paper provides basic information on dental cutters. The provisions of  the experimental  research  methodology are described, including a description  of  a  device  for  modifying the worn surface of a dental cutter and a device for determining its cutting ability. Experimental data are presented and analyzed that reflect an effect on  restoration of a cutting ability of a worn surface of a dental cutter, voltage of a storage capacitor and  number of holes applied to it during its modification. Rational modes of modifying a worn-out surface of a dental mill that provide the greatest recovery of its cutting ability have been determined in the paper. It has been shown that with increasing voltage, the energy of the electric discharge acting on the treated surface increases, which leads to the formation of a single hole of a larger size on it, including metal flows along its edge that extend beyond the initial contour of the worn cutter teeth. These metal flows on the modified surface of the cutter play the role of peculiar cutting and deforming elements. It has been revealed that in the process of modifying the worn surface of the cutter, it is necessary to ensure that there is no overlap of the holes formed on it, i.e. the distance between the centers of adjacent holes should be greater than or equal to the size of metal deposits at their edges. In this case, the metal flows retain their original shape and have the highest height at these pulse parameters, which ensures a higher cutting ability of the modified cutter surface than when the holes are overlapped.

A Truing Technique of Flattening Diamond Grains for Fabricating Microstructures with Fine Surfaces

2008 ◽  
Vol 389-390 ◽  
pp. 350-355
Author(s):  
Takeshi Harada ◽  
Takuya Semba
Keyword(s):  
Surface Roughness ◽  
Electrical Discharge ◽  
Diamond Tool ◽  
Electrical Discharge Machining ◽  
Polycrystalline Diamond ◽  
Mesh Size ◽  
Diamond Disk ◽  
Working Surface ◽  
Work Material ◽  
Tool Profile

A truing technique that can be used to shape the tip of an electroformed diamond tool into a hemisphere and flatten diamond grains on the tool working surface at the same level as the bond face was developed. A polycrystalline diamond disk whose top surface roughened by electrical discharge machining was partially flattened by grinding was used as a truer. Diamond grains on the tool working surface were successfully flattened along the hemispherical tool profile when the grains mesh size of #1000 was employed. In addition, a grinding test using glasslike carbon as a work material revealed that a surface roughness of less than 50 nm Rz could be obtained in both cases when moving the tool on contour and scanning paths.

scholarly journals Processing Characteristics of Micro Electrical Discharge Machining for Surface Modification of TiNi Shape Memory Alloys Using a TiC Powder Dielectric

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1018
Author(s):  
Ziliang Zhu ◽  
Dengji Guo ◽  
Jiao Xu ◽  
Jianjun Lin ◽  
Jianguo Lei ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Modification ◽  
Shape Memory ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Recast Layer ◽  
Powder Concentration ◽  
Micro Electrical Discharge Machining ◽  
Machining Properties

Titanium-nickel shape memory alloy (SMA) has good biomedical application value as an implant. Alloy corrosion will promote the release of toxic nickel ions and cause allergies and poisoning of cells and tissues. With this background, surface modification of TiNi SMAs using TiC-powder-assisted micro-electrical discharge machining (EDM) was proposed. This aims to explore the effect of the electrical discharge machining (EDM) parameters and TiC powder concentration on the machining properties and surface characteristics of the TiNi SMA. It was found that the material removal rate (MRR), surface roughness, and thickness of the recast layer increased with an increase in the discharge energy. TiC powder’s addition had a positive effect on increasing the electro-discharge frequency and MRR, reducing the surface roughness, and the maximum MRR and the minimum surface roughness occurred at a mixed powder concentration of 5 g/L. Moreover, the recast layer had good adhesion and high hardness due to metallurgical bonding. XRD analysis found that the machined surface contains CuO2, TiO2, and TiC phases, contributing to an increase in the surface microhardness from 258.5 to 438.7 HV, which could be beneficial for wear resistance in biomedical orthodontic applications.

Study on the friction characteristics of 304 steel with composite surface modification

2017 ◽  
Vol 69 (2) ◽  
pp. 248-258 ◽  
Author(s):  
Wengang Chen ◽  
Xueyuan Liu ◽  
Lili Zheng
Keyword(s):  
Surface Modification ◽  
Friction And Wear ◽  
Steel Surface ◽  
Testing Machine ◽  
Wear Testing ◽  
Tribological Characteristics ◽  
Textured Surface ◽  
Content Type ◽  
Good Basis ◽  
Modified Surface

Purpose This paper aims to clarify the friction properties of 304 steel surface modification. The surface modification includes laser texturing processing and nitriding treatment on 304 steel surface, and then the friction properties’ test was conducted on different friction directions and different upper test samples by using microfriction and wear testing machine. Design/methodology/approach The diameter and spacing of 100-, 150-, 200-, 300-μm pit array on the surface of 304 steel were calculated using a M-DPSS-50 semiconductor laser device. Then, the textured surface was nitriding-treated using a nitriding salt bath device. The chemical composition, surface morphology and surface microhardness of the composite-modified surface were measured by X-ray diffraction and by using an optical microscope and a microhardness tester. The tribological characteristics of the composite-modified surface were tested by MRTR microcomputer-controlled multifunctional friction and wear testing machine. Findings The result showed that a rule pit texture surface was obtained by the texture processing. The microhardness of nitriding treatment surface reached 574.27HV0.1, which significantly higher than 222.58HV0.1 of 304 steel. The composite-modified surface has excellent anti-friction and wear resistance properties when the upper specimen was GCr15 steel and ZrO2, respectively. The composite-modified surface has excellent anti-friction and anti-wear properties after long time friction under different angles. However, the friction coefficient and wear morphology of the friction pairs are not affected by the friction angle. Research limitations/implications Because of the chosen research approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed propositions further. Practical implications The paper conducted a systematic study of the tribological characteristics of 304 steel composite modification surface and provided a good basis for the extensive application of 304 steel. Social implications The study provides a good basis for the extensive application of 304 steel. Originality/value This paper fulfils an identified need to study the extensive application of 304 steel.

scholarly journals Surface Modification Process by Electrical Discharge Machining with TiC Semi-sintered Electrode.

2001 ◽  
Vol 67 (1) ◽  
pp. 114-119 ◽  
Author(s):  
Toshio MORO ◽  
Akihiro GOTO ◽  
Naotake MOHRI ◽  
Nagao SAITO ◽  
Koei MATSUKAWA ◽  
...  
Keyword(s):  
Surface Modification ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Modification Process ◽  
Sintered Electrode

Study the Re-Sticky Phenomenon of Powder Metallurgy Debris in the Electrical Discharge Machining

2009 ◽  
Vol 83-86 ◽  
pp. 968-976
Author(s):  
A Cheng Wang ◽  
Ken Chuan Cheng ◽  
Yan Cherng Lin ◽  
Jeng Shen Huang
Keyword(s):  
Powder Metallurgy ◽  
Melting Point ◽  
Rotational Speed ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Negative Polarity ◽  
Melting Points ◽  
Working Surface ◽  
Adhesive Effect

The debris re-adhering on the machining surface will affect the workpiece precision in EDM; therefore, the main purpose of this research is to study the re-sticky phenomenon of the powder metallurgy (PMM) in EDM. PMM with different melting points from 1450oC to 3410oC were used as EDM materials, the copper and the tungsten were chosen as the electrodes. The polarity in EDM was depended on the pole of the electrode. For observing the re-sticky position of the debris, the electrode was set no rotation or with 200 rpm rotational speed in EDM. The results showed that the melting point of PMM did not exceed 3000oC (PMM did not contain tungsten); the debris of PMM would not re-stick on the working surface no matter what polarity was used in EDM. However, only negative polarity can cause the re-adhesive effect when the melting point of PMM exceeded 3000oC. The debris would re-stick on any machining position when the electrode was not rotated in EDM. However, the debris would adhere on the central of the working area with 200 rpm rotational speed of the electrode.

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