scholarly journals Regularities in the formation of wear-resistant coatings on steel samples when machining them with electrical discharge

2021 ◽  
Vol 5 (12(113)) ◽  
pp. 83-90
Author(s):  
Dmytro Marchenko ◽  
Viacheslav Kurepin
Keyword(s):  
Wear Resistance ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Operation Mode ◽  
Experimental Studies ◽  
Sharp Decrease ◽  
Transfer Film ◽  
Cathode Voltage ◽  
Wear Resistant Coatings ◽  
Metal Polymer

This paper considers the technology of electrical discharge machining of steel friction pairs and reports the results of experimental studies. Analysis of the experimental studies has shown that increasing the "anode-cathode" voltage leads to a sharp decrease in the micro-hardness of the surface layer. The study has also made it possible to determine the characteristic dimensions of the structural elements, the height parameters of surface roughness. The elemental composition of the resulting surface of a steel 15KHGN2TA sample differs from the composition of coatings and the surface layers of samples modified by electrical discharge machining involving various electrodes. Under the "anode-cathode" system operation mode, a thin layer of coating with a stable modified structure forms on the surface of the cathode due to dissipative processes. It is shown that the height of surface irregularities on sections after friction is higher than on the surface sections outside the friction flow, which is associated with the formation of a friction transfer film on the samples' surface. It was established that the interaction of friction of steel samples treated by electrical discharge machining forms a thin film on the surface of friction of steel samples, which leads to a change in the relief of surfaces with an increase in the height of the micro-protrusions, as well as the structuring of the transfer film in the direction of sliding. The effect of machining steel surfaces by electrical discharge on the wear resistance of metal-polymer tribosystem was established. The implementation of the devised technology could provide a significant increase in the wear resistance of metal-polymer tribojunctions

scholarly journals Tribological researches of electroerosive processing of steel details of cars

2021 ◽  
Vol 99 (1) ◽  
pp. 66-73
Author(s):  
D. Marchenko ◽  
◽  
K. Matvyeyeva ◽  
Keyword(s):  
Experimental Studies ◽  
Sharp Decrease ◽  
Characteristic Size ◽  
Transfer Film ◽  
Initial Surface ◽  
Structural Elements ◽  
Surface Layers ◽  
Cathode Voltage ◽  
Mode Of Operation ◽  
Surface Irregularities

The article considers the technology of electroerosive treatment of steel friction pairs and presents the results of experimental studies. Analysis of experimental studies has shown that an increase in the anode-cathode voltage leads to a sharp decrease in the microhardness of the surface layer. The study also allowed to determine the characteristic size of the structural elements, the height parameters of the surface roughness. The elemental composition of the initial surface of the sample made of steel 15HGN2TA differs from the composition of the coatings and surface layers of the samples modified by electroerosive treatment with different electrodes. In the mode of operation of the "anode - cathode" system on the cathode surface due to dissipative processes, a thin layer of coating of a stable modified structure is formed. It is shown that the height of surface irregularities in the areas after friction is higher than in the areas of the surface outside the friction track, which is associated with the formation on the surface of the samples of the friction transfer film. It was found that the frictional interaction of steel samples treated by electroerosion method forms a thin film on the friction surface of steel samples, which leads to a change in the topography of surfaces with increasing height of microroughnesses and structuring of the transfer film in the sliding direction. The influence of electroerosive treatment of steel surfaces on the wear resistance of the metal-polymer tribosystem was established and the optimal treatment modes were obtained: voltage U = 145-150 V, capacitor capacity C = 225-230 μF, treatment duration t = 3-4 min / cm2, providing the greatest reduction in speed wear of the polymer counterbody and recommended in the development of technological processes of electroerosive treatment.

scholarly journals Wire Electrical Discharge Machining Of Feal Intermetallic Sinters Without And With Addition Of Nano-Al2O3 Oxide Ceramic

2015 ◽  
Vol 60 (3) ◽  
pp. 2447-2456
Author(s):  
M. Ziętala ◽  
T. Durejko ◽  
M. Łazińska
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Abrasive Wear ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Load Capacity ◽  
Abrasive Wear Resistance ◽  
Oxide Ceramic ◽  
Wire Electrical Discharge Machining ◽  
Technological Parameters

AbstractThe influence of the parameters of wire electrical discharge machining (WEDM) on the surface layer of FeAl based sinters with and without Al2O3nanoceramic addition has been studied in this paper. The properties of the sinters surface layer were controlled by WEDM parameters, including time of interval (tp) and amplitude of current (IA). The WEDM roughing and finishing treatments were carried out for selected technological parameters of process. The surface texture (ST) of the sinters after WEDM was analyzed by profilometer method. Theoretical parameters describing abrasive wear resistance of investigated sinters were estimated on the basis on the load capacity curve.On the basis on obtained results it can be stated that there is possibility of shaping geometry of nano-Al2O3doped and undoped FeAl sinters by WEDM. Reduction of the time of interval (tp) and increase of current amplitude (IA) during WEDM deteriorate surface properties. Addition of nano-Al2O3improve the quality of the obtained surface. Applied parameters of WEDM improve theoretical abrasive wear resistance and lubricant maintenance of the nanoceramic doped material in comparison with undoped sinter.

Experimental Studies on Dry WEDM in Improving Surface Quality

2009 ◽  
Vol 626-627 ◽  
pp. 327-332 ◽  
Author(s):  
Tong Wang ◽  
Yu Mei Lu ◽  
Q. Chen ◽  
S.H. Zhou
Keyword(s):  
Surface Quality ◽  
Electrical Discharge ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Experimental Studies ◽  
Pulse Interval ◽  
Wire Length ◽  
Dry Wedm ◽  
Dry And Wet Conditions

This study investigates the dry wire electrical discharge machining (WEDM) in multiple cut. To improve surface quality with high-speed WEDM (HS-WEDM), a new procedure as Gas-liquid Combined Multiple Cut (roughing is processed in dielectric liquid, and semi-finishing is in liquid or gas, while the finishing is in gas) is presented. Effects of pulse duration, pulse interval, peak current, offset, wire winding speed and wire length on roughness, straightness and removal rate had been studied in dry and wet conditions. Experiment results show that multiple cut with dry WEDM in semi-finishing and finishing can improve surface roughness significantly.

Development, Design and Application of a Fatigue Test Bench for High Precision Flexure Hinges

2016 ◽  
Author(s):  
David Schoenen ◽  
Sascha Lersch ◽  
Mathias Hüsing ◽  
Burkhard Corves ◽  
Fritz Klocke ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
Test Bench ◽  
Compliant Mechanisms ◽  
Fatigue Testing ◽  
Electrical Discharge Machining ◽  
Experimental Studies ◽  
Detection Mechanism ◽  
Flexure Hinges ◽  
Adjustment Mechanism ◽  
Research Activities

Due to their advantages compliant mechanisms are very popular. However, they also have some disadvantages as well. Considering that for micromanipulators, which have macroscopic dimensions and a workspace typically in millimeter range, the disadvantages of compliant mechanisms are not as significant as the feasible benefits by reason of their advantages. For instance the range of notch hinges, which are typically used for micromanipulators, can be increased by the use of precision notch hinges with a narrow web thickness. Precision notch hinges are cut efficiently by wire electrical discharge machining. Therefore, flexure hinges are widely used in precision engineering applications. Even though electrical discharge machining is a manufacturing process which is based on the thermo-physical material removal principle with less resulting mechanical stress, it still induces thermal stress on the component. It can be assumed that these influences have an impact on the component’s performance, in particular when the component has filigree structures like precision notch hinges. However, experimental studies on the fatigue of compliant joints are currently missing in research activities. To analyze the manufacturing related influences on the performance of precision notch hinges a series of fatigue tests have to be performed. Thus, a suitable test bench for fatigue testing of precision notch hinges is designed and the used transmission mechanism is explained. Furthermore, the adjustment mechanism for the swivel angle as well as the adjustment mechanism for different loadings of the test specimens are discussed. Additionally, to avoid incorrect loading several design features are explained. To obtain reliable results, the filigree test specimens have to be positioned on the test bench reproducibly in order to ensure recurring test conditions. Thus, the positioning process is explained. In order to increase the number of tested notch hinges, several test specimens are tested simultaneously under the same conditions. Hence, a clear detection of the maximum number of load cycles of each test specimen is ensured by a detection mechanism. This contribution ends with the presentation of preliminary results of the life expectancy analyses of precision notch hinges and a brief discussion of the results.

scholarly journals Effect of Various Type of Nanoparticles on Mechanical and Tribological Properties of Wear-Resistant PEEK + PTFE-Based Composites

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1113
Author(s):  
Sergey V. Panin ◽  
Duc A. Nguyen ◽  
Dmitry G. Buslovich ◽  
Vladislav O. Alexenko ◽  
Aleksander V. Pervikov ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
Film Formation ◽  
Transfer Film ◽  
Contact Conditions ◽  
Mechanical And Tribological Properties ◽  
Contact Wear ◽  
Small Content ◽  
Tribological Contact ◽  
Metal Polymer

The mechanical and tribological properties of polyetheretherketone (PEEK)- and PEEK + PTFE (polytetrafluoroethylene)-based composites loaded with and four types of nanoparticles (carbonaceous, metallic, bimetal oxide, and ceramic) under metal- and ceramic-polymer tribological contact conditions were investigated. It was found that loading with the nanofillers in a small content (0.3 wt.%) enabled improvement of the elastic modulus of the PEEK-based composites by 10–15%. In the metal–polymer tribological contact, wear resistance of all nanocomposites was increased by 1.5–2.3 times. In the ceramic-polymer tribological contact, loading PEEK with metal nanoparticles caused the intensification of oxidation processes, the microabrasive counterpart wear, and a multiple increase in the wear rate of the composites. The three component “PEEK/10PTFE/0.3 nanofillers” composites provided an increase in wear resistance, up to 22 times, for the metal–polymer tribological contact and up to 12 times for the ceramic-polymer one (with a slight decrease in the mechanical properties) compared to that of neat PEEK. In all cases, this was achieved by the polymer transfer film formation and adherence on the counterparts. The various effects of the four types of nanoparticles on wear resistance were determined by their ability to fix the PTFE-containing transfer film on the counterpart surfaces.

scholarly journals Surface Layer Properties after Successive EDM or EDA and Then Superficial Roto-Peen Machining

2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
Agnieszka Dmowska ◽  
Bogdan Nowicki ◽  
Anna Podolak-Lejtas
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Fatigue Strength ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Cold Work ◽  
Microhardness Distribution ◽  
Machine Parts ◽  
Electrical Discharge Alloying ◽  
Work Treatment

The paper presents the results of the influence of basic electrical discharge machining EDM parameters and electrical discharge alloying EDA parameters on surface layer properties and on selected performance properties of machine parts after such machining but also the influence of superficial cold-work treatment applied after the EDM of EDA on modification of these properties. The investigations included texture of the surface, metallographic microstructure, microhardness distribution, fatigue strength, and resistance to abrasive wear. It was proved that the application of the roto-peen after the EDM and the EDA resulted in lowering roughness height up to 70%, the elevation of surface layer microhardness by 300–700 μHV, and wear resistance uplifting by 300%.

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