Author
J. Prohászka
Bio: J. Prohászka is an academic researcher from Hungarian Academy of Sciences. The author has contributed to research in topics: Electrical discharge machining & Surface integrity. The author has an hindex of 6, co-authored 15 publications receiving 328 citations.
Papers
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TL;DR: In this article, the requirements of the materials used for WEDM electrodes that will lead to the improvement of the performance of WEDMs have been investigated, and experiments have been conducted regarding the choice of suitable wire electrode materials.
98 citations
TL;DR: In this paper, the phase transformations of the AISI 304 austenitic stainless steel are studied by different magnetic measurement techniques and it was demonstrated that the type of deformation and the rate of deformations strongly influence the amount of α−-martensite phase.
94 citations
TL;DR: In this paper, the physico-chemical changes occurring during electro-discharge machining of steel (structural, medium carbon and alloyed steels) surfaces are reported and correlated with overall process parameters and metal removal rates.
80 citations
TL;DR: In this article, the authors report on the fabrication of bimetallic components consisting of aluminium and copper plates by explosive cladding and subsequent rolling, and evaluate the surface integrity of the resulting bimetallics in terms of surface topography, microhardness variation and metallurgical changes through the thickness of the cladded/rolled plates.
37 citations
01 Jan 1991
TL;DR: In this article, the results of a series of experiments on two types of concrete steels subjected to Rapid Heat Treatment (RHT) are reported, and the results show that mechanical properties can be improved dramatically by the RHT.
Abstract: In this paper the authors report the results of a series of experiments on two types of concrete steels subjected to rapid heat treatment (RHT). The results show that mechanical properties can be improved dramatically by the RHT. RHT involves a process whereby samples are heated up by their Joule heat. Because of this the steels composed of ferrite and pearlite transform to austenite in a short time (0.001-5 sec) depending on the current density. Austenite grains formed this way are much smaller than in the normally treated steels. The ferrite, pearlite and martensite originating from this austenite also have a very small grain size. Therefore the RHT procedure, in compliance with the Hall-Petch equation, produces higher strengths. The following are the results of a research program involving the quality improvement of two types of steels, often used for concrete reinforcement, by rapid heat treatment (RHT). The two types of steels treated were an unalloyed low carbon steel and a HSLA steel.
9 citations
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TL;DR: In this article, the relationship between EDM parameters and surface cracks was studied by using a full factorial design, based upon discharge current and pulse-on time parameters, and established a crack prediction map, and indicated whether or not cracks are likely to form for a given pulse-ON and pulse current combination.
301 citations
TL;DR: The Fe35Mn alloy was found to be essentially austenitic with fine MnO particles aligned along the rolling direction, and it exhibits antiferromagnetic behaviour and its magnetic susceptibility is not altered by plastic deformation, providing an excellent MRI compatibility.
Abstract: An Fe–35 wt-%Mn alloy, aimed to be used as a metallic degradable biomaterial for stent applications, was prepared via a powder metallurgy route. The effects of processing conditions on the microstructure, mechanical properties, magnetic susceptibility and corrosion behaviour were investigated and the results were compared to those of the SS316L alloy, a gold standard for stent applications. The Fe35Mn alloy was found to be essentially austenitic with fine MnO particles aligned along the rolling direction. The alloy is ductile with a strength approaching that of wrought SS316L. It exhibits antiferromagnetic behaviour and its magnetic susceptibility is not altered by plastic deformation, providing an excellent MRI compatibility. Its corrosion rate was evaluated in a modified Hank's solution, and found superior to that of pure iron (slow in vivo degradation rate). In conclusion, the mechanical, magnetic and corrosion characteristics of the Fe35Mn alloy are considered suitable for further development ...
282 citations
TL;DR: Among the alloys studied in this work, the Fe-35%Mn alloy shows mechanical properties and degradation behavior closely approaching those required for biodegradable stents application.
Abstract: Designing materials having suitable mechanical properties and targeted degradation behavior is the key for the development of biodegradable materials for medical applications, including stents. A series of Fe-Mn alloys was developed with the objective to obtain mechanical properties similar to those of stainless steel 316L and degradation behavior more suited than pure iron. Four alloys with Mn content ranging between 20 and 35 wt % were compared in this study. Their microstructure, mechanical properties, magnetic properties as well as degradation behavior were carefully investigated. Results show that their microstructure is mainly composed of gamma phase with the appearance of epsilon phase in alloys having a lower Mn content. The yield strength and elongation of alloys was comprised between 234 MPa and 32% for Fe-35%Mn alloy to 421 MPa and 7.5% for the Fe-20%Mn alloy. All alloys show similar magnetic susceptibility ( approximately 1.8 x 10(-7) m(3)/kg) in the quenched condition. This magnetic susceptibility remains constant after plastic deformation for all the tested alloys except for the Fe-20%Mn alloy. The corrosion rate was higher than pure iron. Among the alloys studied in this work, the Fe-35%Mn alloy shows mechanical properties and degradation behavior closely approaching those required for biodegradable stents application.
216 citations
TL;DR: In this paper, a finite element-based model for the electric discharge machining (EDM) process is presented, which uses process parameters such as power input, pulse duration, etc., to predict the transient temperature distribution, liquid-and solid-state material transformation, and residual stresses that are induced in the workpiece as a result of a single-pulse discharge.
216 citations
TL;DR: This well-trained neural network model is shown to be effective in estimating the MRR and is improved using optimized machining parameters.
Abstract: The present work reports on the development of modeling and optimization for micro-electric discharge machining (μ-EDM) process. Artificial neural network (ANN) is used for analyzing the material removal of µ-EDM to establish the parameter optimization model. A feed forward neural network with back propagation algorithm is trained to optimize the number of neurons and number of hidden layers to predict a better material removal rate. A neural network model is developed using MATLAB programming, and the trained neural network is simulated. When experimental and network model results are compared for the performance considered, it is observed that the developed model is within the limits of the agreeable error. Then, genetic algorithms (GAs) have been employed to determine optimum process parameters for any desired output value of machining characteristics. This well-trained neural network model is shown to be effective in estimating the MRR and is improved using optimized machining parameters.
163 citations