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1

Influence of Cutting Conditions on Temperature Distribution in Face Milling of Inconel 718 Nickel-Chromium Alloy

Grzesik W., Nieslony P., Habrat W., Laskowski P.

Journal of Machine Engineering

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2015

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Vol. 15, No. 2

5--16

EN

This paper presents 3D FEM simulation results obtained for the milling operations on a nickel-chromium alloy (Inconel 718) using the Johnson-Cook material constitutive model and variable cutting conditions. Face milling tests were carried out using silicon-aluminum-oxygen-nitrogen (SiAlON) ceramic cutting tools inserts. The machining conditions were selected based on real production data (cutting speed of vc=750 and 800 m/min, feed of f=0.1, 0.125 and 0.15 mm/t, depth of cut of ap=1, 1.5 and 2 mm). The FEM simulations include the maximum and average values of the cutting temperature. They were compared with experimental data obtained by using the high speed infra-red camera.

2

Experimental and simulation investigations of face milling process of Ti-6Al-4V titanium alloy

Niesłony P., Grzesik W., Habrat W.

Advances in Manufacturing Science and Technology

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2015

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Vol. 39, nr 1

39--52

EN

This paper is focused on the finite element analysis of machining of Ti6Al4V titanium alloy in a nonorthogonal (3D) face milling process. The study was conducted for face milling with the cutting speed of 80 m/min, depth of cut of 1 mm, cutting width of 10 mm and different feed rates. The FEM simulations include the cutting force components and average maximum cutting temperatures. The simulation results were compared with experimental data obtained for similar milling process configuration. It was found that the kind of FEM constitutive model influences the force and temperature values. In this case the cutting force has a better match with experimental data when using the JC model. On the other hand, a good fitting for both feed and passive forces was achieved for the PL model. Additionally, a very good fitting for the cutting temperature using PL FEM model was obtained. It was also found that the feed rate has a significant effect on the average interface temperature and can be modelled by using FEM material models presented in the article.

PL

W pracy prowadzono analizę wyników symulacji procesu frezowania walcowo-czołowego stopu tytanu Ti6Al4V, w układzie nieortogonalnym (3D) z zastosowaniem metody elementów skończonych. W procesie frezowania płaskiego stosowano prędkość skrawania 80 m/min, głębokość skrawania 1 mm, szerokość skrawania 10 mm, dla różnych wartości posuwów. Przy użyciu MES określono wartości składowych sił skrawania oraz maksymalną wartość temperatury skrawania. Walidację wyników symulacyjnych i badań eksperymentalnych prowadzono dla takich samych wartości warunków obróbki. Stwierdzono, że rodzaj konstytutywnego modelu MES ma wpływ na wartości siły i temperatury skrawania. W tym ujęciu dobrą zgodność danych symulacji normalnych i eksperymentalnych, dla przypadku składowej głównej siły skrawania, uzyskano przy zastosowaniu modelu JC. Natomiast lepsze dopasowanie dla składowej posuwowej i odporowej (pasywnej) uzyskano dla modelu PL. Dodatkowo dobre dopasowanie wyniku symulacji i eksperymentu, dla temperatury skrawania, uzyskano także dla modelu MES typu PL. Stwierdzono, że posuw ma znaczny wpływ na wartość średniej temperatury skrawania. Modelowanie tych oddziaływań można realizować, stosując modele materiałowe MES przedstawione w pracy.

3

3D FEM simulations and experimental studies of the turning process of Inconel 718 superalloy

Nieslony P., Grzesik W., Żak K., Laskowski P.

Journal of Machine Engineering

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2014

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Vol. 14, No. 2

16--26

EN

This paper is focused on the finite element analysis of machining of Inconel 718 superalloy in a non-orthogonal (3D) turning process. The cutting experiments were carried out on the cylindrical workpiece of Inconel 718 with the cutting speed of 60-90 m/min, the feed rate of 0.1 mm/rev and different depths of cut. The FEM simulations include the average and maximum interface temperatures, the resultant cutting force and its three components and the chip thickness obtained for the 3D turning process. The simulation results were compared with experimental data obtained in the non-orthogonal process. It was found that the experimental values of the cutting forces are underestimated (about 23-30%) in relation to the FEM simulation data. Additionally, it was noted that the cutting depth has a significant effect on the average interface temperature only when using a non-orthogonal turning process.

4

Distributed electrothermal modeling methodology for MOS gated power devices simulations

Marcault E, Tounsi P., Massol J.-L, Dorkel J.-M

International Journal of Microelectronics and Computer Science

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2013

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Vol. 4, nr 4

148--152

EN

Currently electro-thermal simulations performed with 3D FEM simulators like ANSYS or COMSOL Multiphysics are limited to an imposed current ﬂow through resistive materials. However, in the case of power MOS gated transistors like VDMOS transistors or IGBT, the channel resistance evolves with the gate voltage. This phenomenon is usually neglected in ON-state applications but seems to be determinant in switching application. Furthermore all the MOS cells of the transistors are not at the same temperature. This paper deals with a methodology that could allow taking into account the impact of the gate control and the MOS cells current distribution during 3D FEM electro-thermal simulations.

5

Prediction of mechanical properties of hot rolled steel products

Simecek P., Hajduk D.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

395-398

EN

Purpose: Model for prediction of mechanical properties of rolled steel products after final cooling from exit rolling temperature is one of the basis component of any software for complex computer simulation of rolling technologies. Theoretical background and implementation of such software tool is described. Design/methodology/approach: After calculation of cooling curves by any technology dependent Shell the software tool MECHP can be called to predict CCT Diagram from current chemical composition of steel and initial properties of deformes austenite first than structure shares (percentage of ferrite, pearlite, bainite and martensite) resulting from austenite decomposition process for given cooling curve and finally mechanical properties of final product after cooling (hardness, yield stress, tensile strength) are calculated. Implementation of MECHP tool into the software RollFEM3D Finite Elements Method simulation of rolling processes is presented. Findings: comparison of MECHP calculations with measured process data (water cooling and subsequent air cooling of hot rolled narrow plate and wire) shows correspondence that is satisfactory for using in control of process cooling technology. Practical imlications: Results of verification showed that the software tool MECHP is implementable as a postprocessor into off-line rolling process simulation software or can be used as a mechanical properties predictor in software for on-line control of cooling. Originality/value: Developing of technology independent Library solving the problem of final mechanical properties prediction for various kinds of rolling technologies.