Effect of Laser Radiation on InSe and GaSe Thin Films Grown via Laser Sublimation and Chemical Deposition

Kozochkin

Porvatov

et al. 2019

Heliyon

The productivity of electrical discharge machining (EDM) is relatively low owing to the natural laws of electrical erosion. Precise EDM demands uninterrupted control of the discharge gap and adjustment of process parameters. It is particularly critical for processing large workpieces with complex linear surfaces and for materials with threshold conductivities such as the new advanced ceramic nanocomposites Al2O3+TiC and Al2O3+SiCw+TiC(30–40%). In these cases, adequate flushing of erosion products is hampered by the geometry of the working space or by the small value of the required discharge gap, which does not exceed 2.2–2.5 μm. The methods of adaptive control in modern computer numerical control systems of EDM equipment based on measuring the electrical parameters in the working zone have been shown to be ineffective in the cases described above. This study aims to investigate the natural phenomena of material sublimation under discharge pulses for conductive ceramics and nanocomposites. The measured conductivities of the samples are higher than the percolation threshold. However, the question of machinability remains open owing to detected processing interruptions and poor quality of machined surfaces. New knowledge on EDM of conductive ceramics and nanocomposites can improve the final quality of the machined surfaces and productivity of the method by the introduction of advanced monitoring and control methods based on acoustic emissions. The manuscript presents an up-to-date overview and current state of the research on the subject area. The obtained morphology of the samples and discussion of the findings complete the experimental part of the study. The scientific basis for a new type of adaptive control system is provided. This can improve the effectiveness of parameter control for machining conductive ceramics and nanocomposites and contribute to an increase in the EDM performance for the most critical cases.

Section: Discussionmentioning

confidence: 99%

Electrical discharge machining of ceramic nanocomposites: sublimation phenomena and adaptive control

Kozochkin

Porvatov

et al. 2019

Heliyon

“…These processes have different energy carriers by nature, however both technologies affect the substance with a flow of thermal energy with a high power density. This also determines the generality of the properties of AE signals accompanying these processes [25][26][27]35,36]. Pulses of laser radiation were delivered in a series of 1000 pulses at each point.…”

Section: Discussionmentioning

confidence: 99%

Investigation of Situational Correlations of Wire Electrical Discharge Machining of Superhard Materials with Acoustic Emission Characteristics

Kozochkin

Porvatov

et al. 2023

Metals

The purpose of the research is to find relationships between the parameters of the acoustic emission signals accompanying the electroerosive processing with a wire electrode of metals and hard alloys and the most important process indicators. These indicators include an increase in the concentration of erosion products in the interelectrode gap, an increase in the probability of wire electrode breakage, the efficiency of the supplied energy, the current productivity. The article presents the results of the study of acoustic emission signals during the processing of hard alloys with a cutting machine. The main attention is paid to the period preceding the breakage of the wire electrode. Changes in the parameters of acoustic emission a few seconds before failure are shown, and the possibility of preventing wire breakage by monitoring the parameters of acoustic emission signals is established. To evaluate the efficiency of the energy supplied to the processing zone, a dynamic model is proposed, with the help of which the processing efficiency is estimated by changing the transmission coefficients in one or several frequency ranges. To explain the situation that occurs in the processing zone with an increase in the concentration of erosion products, the article draws a parallel between electroerosive and laser processing, related to technologies of processing with concentrated flows of energy. Studies have shown that acoustic emission signals can be used to search for rational processing modes and improve automatic control systems for electroerosive equipment.

“…Furthermore, as it was mentioned before, the occurred physical sublimation of the electrodes and chemical interaction of the components occurs faster for easy-to-melt materials. During the electrical pulses' interruption, the formed substances depose on the formed nanocarcass or nanoframe of the heat-resistant components of the workpiece material [51][52][53][54][55].…”

Section: Introductionmentioning

confidence: 99%

Electrical Discharge Machining of Oxide Nanocomposite: Nanomodification of Surface and Subsurface Layers

Волосова

Okunkova

et al. 2020

JMMP

The work is devoted to the research of the changes that occur in the subsurface layer of the workpiece during electrical discharge machining of conductive nanocomposite based on alumina with the use of a brass tool. The nanocomposite of Al2O3 + 30% of TiC was electroerosively machined in a water and hydrocarbon oil. The process of electrical discharge machining is accompanied by oscillations that were registered by diagnostic means. The obtained surface of the samples was researched by the means of scanning electron microscopy and X-ray photoelectron spectroscopy. The observed surface and subsurface changes provide grounding for the conclusions on the nature of processes and reactions that occur between two electrodes and nanomodification of the obtained surfaces that can be an advantage for a series of applications.