The Experts below are selected from a list of 1221 Experts worldwide ranked by ideXlab platform
T A Dean - One of the best experts on this subject based on the ideXlab platform.
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Three-Dimensional Finite Element Modelling of Forging of a Titanium Alloy Aerofoil Sectioned Blade
Journal of Manufacturing Science and Engineering-transactions of The Asme, 1999Co-Authors: J W Brooks, T A DeanAbstract:Analysis of the Forging of aerofoil blades, particularly those for aeroengines, is a complex operation because of the complicated three-dimensional geometry and the non steadystate contact between the workpiece and the Die surface. In this paper a three-dimensional analysis of the Hot Forging ofa titanium compressor blade, currently being made and used commercially, using the finite element method is presented and validated by the results from Hot-Die Forging tests. The process is modelled assuming isothermal conditions, the main interest being the mechanics of the deformation. Abaqus/Explicit FE software has been used for process simulation in which the complicated Die form, assumed rigid, has been modelled using smoothed Bezier surfaces which enable Die/workpiece contact phenomena to be handled effectively. Predicted strain patterns in sections of Forging, using either 2-D or 3-D analysis are compared. It is shown that the experimental Forging load and the overall flow pattern are predicted by the analysis with good accuracy.
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experimental and theoretical analysis of deformation and microstructural evolution in the Hot Die Forging of titanium alloy aerofoil sections
Journal of Materials Processing Technology, 1999Co-Authors: Z M Hu, T A DeanAbstract:Abstract A study of the Hot Die Forging of titanium alloy aerofoil sections, carried out both numerically and experimentally, is described. A two-dimensional thermal–plastic coupled finite-element model is employed to study the mechanical and thermal interaction between the Forging Dies and the workpiece. Attention has been paid to deformation, temperature, stress and strain inside the blade and these parameters have been used in combination with an internal state variable to determine the evolution of the microstructure of the blade during Hot Forging. A comparison of theoretical with experimental results shows that the developed model may be used to accurately predict microstructural parameters.
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The interfacial heat transfer coefficient in Hot Die Forging of titanium alloy
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 1998Co-Authors: J W Brooks, T A DeanAbstract:AbstractAn investigation of Die temperature changes and the heat transfer coefficient during Hot Forging of titanium alloy has been carried out using experiments and a thermal-plastic coupled finite element analysis. Hot Ti-6A1–4V rings were forged between two heated flat Dies made of Inconel alloy IN718. The bottom Die was instrumented with high-response thermocouples on its surface and subsurface. The recorded temperatures were analysed and used to determine the interface heat transfer coefficient between the Die and the workpiece in conjunction with the thermal-plastic coupled finite element analysis using a reverse algorithm. The coefficients determined were then used in a finite element model for the analysis of the upsetting process and the results produced were in good agreement with the experimental data.
Z M Hu - One of the best experts on this subject based on the ideXlab platform.
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experimental and theoretical analysis of deformation and microstructural evolution in the Hot Die Forging of titanium alloy aerofoil sections
Journal of Materials Processing Technology, 1999Co-Authors: Z M Hu, T A DeanAbstract:Abstract A study of the Hot Die Forging of titanium alloy aerofoil sections, carried out both numerically and experimentally, is described. A two-dimensional thermal–plastic coupled finite-element model is employed to study the mechanical and thermal interaction between the Forging Dies and the workpiece. Attention has been paid to deformation, temperature, stress and strain inside the blade and these parameters have been used in combination with an internal state variable to determine the evolution of the microstructure of the blade during Hot Forging. A comparison of theoretical with experimental results shows that the developed model may be used to accurately predict microstructural parameters.
Mahendramohan Balathandayuthapani - One of the best experts on this subject based on the ideXlab platform.
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temperature changes and loads during Hot Die Forging of a gamma titanium aluminide alloy
Journal of Materials Processing Technology, 2005Co-Authors: R Srinivasan, Mahendramohan BalathandayuthapaniAbstract:Abstract Non-isothermal Forging is a non-steady state deformation process since temperatures of Die, workpiece and environment are different from each other. The workpiece temperature decreases during the process by heat transfer to the Dies and the environment. On the other hand, deformation heating can increase the workpiece temperature. The deformation loads depend not just on the initial temperature of the workpiece and the strain rate, but also on the duration of the deformation. This paper presents the results of a study that involved both physical experiments and finite element simulation of the non-isothermal deformation of a gamma titanium–aluminide.
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Temperature Changes and Loads During Hot-Die Forging of a Gamma Titanium–Aluminide Alloy
Journal of Materials Processing Technology, 2005Co-Authors: R Srinivasan, Mahendramohan Balathandayuthapani, Wenying YanAbstract:Abstract Non-isothermal Forging is a non-steady state deformation process since temperatures of Die, workpiece and environment are different from each other. The workpiece temperature decreases during the process by heat transfer to the Dies and the environment. On the other hand, deformation heating can increase the workpiece temperature. The deformation loads depend not just on the initial temperature of the workpiece and the strain rate, but also on the duration of the deformation. This paper presents the results of a study that involved both physical experiments and finite element simulation of the non-isothermal deformation of a gamma titanium–aluminide.
Dalibor Vojtěch - One of the best experts on this subject based on the ideXlab platform.
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structural and mechanical characteristics of the al 23si 8fe 5mn alloy prepared by combination of centrifugal spraying and Hot Die Forging
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2014Co-Authors: Karel Dám, Filip Průša, Dalibor VojtěchAbstract:Abstract The structure, mechanical properties and thermal stability of the hypereutectic Al–23Si–8Fe–5Mn (wt%) alloy were stuDied. The alloy was prepared by the unique method of combining centrifugal spraying and Hot Die Forging. The rapidly solidified semiproduct was prepared by pouring the melt onto a rapidly rotating graphite disc. This semiproduct was then compacted by Die Forging at the temperature of 550 °C. It was shown that the preparation method led to a compact pore-free material with very good compressive mechanical properties. The results of thermal stability testing revealed that the mechanical properties do not change significantly at high temperature, even after 100 h of annealing at 400 °C. In addition, the Al–23Si–8Fe–5Mn alloy exhibited very good creep resistance. The structure contained a very fine intermetallic phase, which was identified as α-AlFeMnSi. This phase had a significant impact on the hardness and the yield strength of the material, but the primary impact of this phase was on the thermal stability of the material. The Al–23Si–8Fe–5Mn alloy was compared to a commercial casting Al–12Si–1Cu–1Mg–1Ni alloy, which is used in high temperature automotive applications. The room temperature mechanical properties of the two alloys were comparable, but the Al–23Si–8Fe–5Mn alloy exhibited considerably better thermal stability. Therefore, this alloy can be considered a promising alternative to conventional alloys. It was also demonstrated that the combination of centrifugal spraying and Die Forging is a suitable method for processing Al–Si based alloys with high iron contents.
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Structural and mechanical characteristics of the Al–23Si–8Fe–5Mn alloy prepared by combination of centrifugal spraying and Hot Die Forging
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2014Co-Authors: Karel Dám, Filip Průša, Dalibor VojtěchAbstract:Abstract The structure, mechanical properties and thermal stability of the hypereutectic Al–23Si–8Fe–5Mn (wt%) alloy were stuDied. The alloy was prepared by the unique method of combining centrifugal spraying and Hot Die Forging. The rapidly solidified semiproduct was prepared by pouring the melt onto a rapidly rotating graphite disc. This semiproduct was then compacted by Die Forging at the temperature of 550 °C. It was shown that the preparation method led to a compact pore-free material with very good compressive mechanical properties. The results of thermal stability testing revealed that the mechanical properties do not change significantly at high temperature, even after 100 h of annealing at 400 °C. In addition, the Al–23Si–8Fe–5Mn alloy exhibited very good creep resistance. The structure contained a very fine intermetallic phase, which was identified as α-AlFeMnSi. This phase had a significant impact on the hardness and the yield strength of the material, but the primary impact of this phase was on the thermal stability of the material. The Al–23Si–8Fe–5Mn alloy was compared to a commercial casting Al–12Si–1Cu–1Mg–1Ni alloy, which is used in high temperature automotive applications. The room temperature mechanical properties of the two alloys were comparable, but the Al–23Si–8Fe–5Mn alloy exhibited considerably better thermal stability. Therefore, this alloy can be considered a promising alternative to conventional alloys. It was also demonstrated that the combination of centrifugal spraying and Die Forging is a suitable method for processing Al–Si based alloys with high iron contents.
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Highly Thermally Stable Light-Weight Al Based Alloys Prepared by Centrifugal Atomization and Powder Compaction
Materials Science Forum, 2014Co-Authors: Dalibor Vojtěch, Karel Dám, Filip PrůšaAbstract:Combination of centrifugal melt spraying and Hot Die-Forging of a rapidly solidified semi-product was presented as a promising and inexpensive method for processing of aluminium based alloys of unconventional chemical compositions, e.g., those containing high concentrations of thermally stabilizing transition metals. In our study, the use of this processing method is illustrated for the Al–23Si–8Fe–5Mn (wt. %) alloy. Structure was examined by LM, SEM, EDS and XRD. Mechanical properties were determined by hardness and compressive tests. Thermal stability was assessed by measuring the hardness development during long-term annealing, elevated temperature compressive tests and creep tests. The research showed that the investigated alloy exhibits excellent thermal stability as compared with commercial thermally stable aluminium alloys currently used in automotive and aerospace industry.
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Thermally stable Al–Fe–Mn-based alloy prepared by centrifugal spraying and Hot Die Forging
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2014Co-Authors: Karel Dám, Dalibor VojtěchAbstract:Abstract An Al–8Fe–5Mn (wt%) alloy was prepared by a unique method combining centrifugal spraying with Hot Die Forging. The rapidly solidified semi-product was prepared by pouring the melt onto a rapidly rotating graphite disc. The semi-product was then compacted by Die Forging at a temperature of 550 °C. The structure, mechanical properties and thermal stability of the alloy were investigated. The investigated alloy was compared to a commercial casting Al–12Si–1Cu–1Mg–1Ni alloy (EN AC-48000), which is used in high temperature automotive applications. The preparation method produced a compact pore-free material. A very fine intermetallic phase Al 6 (Mn,Fe) was detected in the structure, which was found to primarily impact the thermal stability of the material. Thermal stability tests (400 °C, 100 h) showed that the hardness of the investigated alloy dropped from approximately 90 to 80 HV (11%) and the yield strength from 210 to 195 MPa (7%). The hardness of the commercial alloy dropped from 110 to 55 HV (50%) and the yield strength from 330 to 150 MPa (55%). At high temperatures, the yield strengths of the Al–8Fe–5Mn alloy and the commercial casting alloy were comparable – the yield strength at 400 °C was 75 MPa for the former and 78 MPa for the latter. The combination of centrifugal spraying and Die Forging was also found to be a suitable processing route for aluminium alloys with high iron content.
R Srinivasan - One of the best experts on this subject based on the ideXlab platform.
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temperature changes and loads during Hot Die Forging of a gamma titanium aluminide alloy
Journal of Materials Processing Technology, 2005Co-Authors: R Srinivasan, Mahendramohan BalathandayuthapaniAbstract:Abstract Non-isothermal Forging is a non-steady state deformation process since temperatures of Die, workpiece and environment are different from each other. The workpiece temperature decreases during the process by heat transfer to the Dies and the environment. On the other hand, deformation heating can increase the workpiece temperature. The deformation loads depend not just on the initial temperature of the workpiece and the strain rate, but also on the duration of the deformation. This paper presents the results of a study that involved both physical experiments and finite element simulation of the non-isothermal deformation of a gamma titanium–aluminide.
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Temperature Changes and Loads During Hot-Die Forging of a Gamma Titanium–Aluminide Alloy
Journal of Materials Processing Technology, 2005Co-Authors: R Srinivasan, Mahendramohan Balathandayuthapani, Wenying YanAbstract:Abstract Non-isothermal Forging is a non-steady state deformation process since temperatures of Die, workpiece and environment are different from each other. The workpiece temperature decreases during the process by heat transfer to the Dies and the environment. On the other hand, deformation heating can increase the workpiece temperature. The deformation loads depend not just on the initial temperature of the workpiece and the strain rate, but also on the duration of the deformation. This paper presents the results of a study that involved both physical experiments and finite element simulation of the non-isothermal deformation of a gamma titanium–aluminide.