Sub-Microstructure of Surface and Subsurface Layers after Electrical Discharge Machining Structural Materials in Water

Grigoriev, S. N.; Волосова, М. А.; Okunkova, Anna A.; Fedorov, S. Yu.; Hamdy, Khaled; Podrabinnik, Pavel

doi:10.3390/met11071040

Cited by 6 publications

(3 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At the same time, a higher conductivity of the material to be processed requires a larger discharge gap, which is about 170 and 200 µm for mild steel and copper [68], and 48-50 µm for materials with threshold electrical conductivity [69]. Thus, the electrical conductivity and the discharge gap are proportional [70]. The suspension was instantly stirred using an IL100-6/1 ultrasonic unit (LLC "Ultrasonic Technology-INLAB", Saint Petersburg, Russia) at a frequency of 22 kHz to avoid powder conglomerations [71].…”

Section: Assisting Powder-mixed Mediummentioning

confidence: 99%

Simulation of Mechanical and Thermal Loads and Microtexturing of Ceramic Cutting Inserts in Turning a Nickel-Based Alloy

Волосова

Okunkova

Hamdy

et al. 2023

Metals

Self Cite

View full text Add to dashboard Cite

This paper is devoted to the problem of wear resistance in square Si3N4 ceramic cutting inserts, which exhibit high hardness and strength, in combination with brittleness, in machining super alloys (e.g., a nickel-based alloy of Inconel 718 type) for aviation purposes, when subjected to increased mechanical and thermal loads. Microtextures were proposed to reduce the intensity of the contact loads on the pad between the cutting edge and the workpiece. The simulation of the mechanical and thermal loads demonstrated the superior ability of the faces with the preformed microgrooves (125 µm in width) compared to microwells (ø100 µm). The tense state was 4.97 times less, and there were 2.96 times fewer deformations. It was shown that they hamper the development of thermal fields at 900 °C. Two types of microtextures (210 µm-wide microgrooves and microwells 80 µm in diameter) were produced on the rake faces of the cutting inserts via an innovative and integrated approach (the electrical discharge machining of dielectrics using multifunctional and TiO2-assisted powder), and a conductive and wear-resistant TiN coating was deposited via magnetron vacuum plasma sputtering (95%N2/5%Ar). The failure criterion in turning was 400 µm. An increase of 30% in tool wear resistance was demonstrated.

show abstract

Section: Assisting Powder-mixed Mediummentioning

confidence: 99%

Simulation of Mechanical and Thermal Loads and Microtexturing of Ceramic Cutting Inserts in Turning a Nickel-Based Alloy

Волосова

Okunkova

Hamdy

et al. 2023

Metals

Self Cite

View full text Add to dashboard Cite

show abstract

“…Electro Discharge Machining (EDM) is a technologically advanced, precision machining method. EDM is mainly used in industries and research fields of aerospace, medical, dental, and automotive engineering in order to manufacture ceramics [ 1 ], modify surface or the sub-surface microstructure [ 2 , 3 ] as well as optimize the machining parameters [ 4 ]. The process involves triggering a spark-generated erosion process between two electrodes, one of which is the tool and the other is the workpiece [ 5 ].…”

Section: Introductionmentioning

confidence: 99%

“…The results pointed out that the anodic tool polarity produced a more uniform, hard, and brittle sublayer with a Face-Centered-Cubic (FCC) structure rich in carbon. In his study, Grigoriev et al [ 2 ] machined X10CrNiTi18-10 steel by wire-EDM with water as a dielectric medium. The subsurface analysis revealed a nanomodification of the layers by combining elements between the wire electrode and the workpiece.…”

Section: Introductionmentioning

confidence: 99%

Surface and Subsurface Quality of Titanium Grade 23 Machined by Electro Discharge Machining

et al. 2021

View full text Add to dashboard Cite

Electrical Discharge Machining (EDM) is a non-traditional cutting technology that is extensively utilized in contemporary industry, particularly for machining difficult-to-cut materials. EDM may be used to create complicated forms and geometries with great dimensional precision. Titanium alloys are widely used in high-end applications owing to their unique intrinsic characteristics. Nonetheless, they have low machinability. The current paper includes an experimental examination of EDM’s Ti-6Al-4V ELI (Extra Low Interstitials through controlled interstitial element levels) process utilizing a graphite electrode. The pulse-on current (IP) and pulse-on time (Ton) were used as control parameters, and machining performance was measured in terms of Material Removal Rate (MRR), Tool Material Removal Rate (TMRR), and Tool Wear Ratio (TWR). The Surface Roughness (SR) was estimated based on the mean roughness (SRa) and maximum peak to valley height (SRz), while, the EDMed surfaces were also examined using optical and SEM microscopy and cross-sections to determine the Average White Layer Thickness (AWLT). Finally, for the indices above, Analysis of Variance (ANOVA) was conducted, whilst semi-empirical correlations for the MRR and TMRR were given using the Response Surface Method (RSM). The results show that the pulse-on time is the most significant parameter of the machining process that may increase the MRR up to 354%. Pulse-on current and pulse-on time are shown to have an impact on the surface integrity of the finished product. Furthermore, statistics, SEM, and EDX images on material removal efficiency and tool wear rate are offered to support the core causes of surface and sub-surface damage. The average microhardness of the White Layer (WL) is 1786 HV.

show abstract

Vibroacoustic Monitoring Features of Radiation-Beam Technologies by the Case Study of Laser, Electrical Discharge, and Electron-Beam Machining

Grigoriev¹,

Kozochkin²,

Волосова³

et al. 2021

Metals

View full text Add to dashboard Cite

A feature of radiation-beam technologies is similar processes associated with phase transformations and chemical reactions that cause changes in the volume of matter, accompanied by the vibroacoustic energy release distributed through the equipment flexible system in a wide frequency range (up to 40 kHz and high for 150 ms). The vibroacoustic signal amplitude accompanying radiation-beam technologies depends on the power density and process performance. The accelerated growth of the high-frequency components of the vibroacoustic signal is associated with the activation of the processes of volumetric boiling and evaporation/sublimation of the material. The Kf parameter, introduced as the ratio of the effective amplitudes of the low-frequency and high-frequency ranges of the vibroacoustic signal, monitors the results of high-energy flows’ impact on the material in the direction of vaporization/sublimation. The Kf parameter decrease tendency shows an increase in the proportion of the substance evaporated during laser treatment. The Kf parameter control allows the indication of the short-circuit approach in electric discharge machining, which allows increased productivity and reliability of processing. The monitoring of the Kf parameter helps to select rational processing modes, preventing excessive evaporation, providing the necessary intensity of the impact power to trigger the necessary chemical reactions in surface electron-beam alloying.

show abstract

Sub-Microstructure of Surface and Subsurface Layers after Electrical Discharge Machining Structural Materials in Water

Cited by 6 publications

References 60 publications

Simulation of Mechanical and Thermal Loads and Microtexturing of Ceramic Cutting Inserts in Turning a Nickel-Based Alloy

Simulation of Mechanical and Thermal Loads and Microtexturing of Ceramic Cutting Inserts in Turning a Nickel-Based Alloy

Surface and Subsurface Quality of Titanium Grade 23 Machined by Electro Discharge Machining

Vibroacoustic Monitoring Features of Radiation-Beam Technologies by the Case Study of Laser, Electrical Discharge, and Electron-Beam Machining

Contact Info

Product

Resources

About