The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Joel Andersson - One of the best experts on this subject based on the ideXlab platform.
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weldability of ni based superalloys Waspaloy and haynes 282 a study performed with varestraint testing
Research & Reviews: Journal of Material Sciences, 2016Co-Authors: Jonny Jacobsson, Joel Andersson, Anssi Brederholm, Hannu HänninenAbstract:There is a need for materials with high strength, oxidation resistance, thermal stability and adequate weldability in order to facilitate the production of large structural jet engine components. Therefore, the weldability of Waspaloy® and Haynes® 282® have been evaluated using the Varestraint weldability test. The experiments reveal that Waspaloy® has a higher susceptibility to hot cracking compared to Haynes® 282®. This conclusion is supported by increased total crack length (10 mm or more) and larger brittle temperature range (approx. 65°C) for Waspaloy® when compared to Haynes® 282® in Varestraint and Gleeble hot ductility tests, respectively. The cracking in Haynes® 282® seems to be connected with a secondary phase which presumably can be associated with Ti-Mo based MC-type carbide observed in the fusion zone. Also, a surrounding segregated area is present near this secondary phase as well as along the grain boundaries. Furthermore, micro-Vickers hardness results revealed more or less the same weld metal hardness (260- 280 HV) but a difference in the base metal hardness. The weld metal hardness of Waspaloy® was lower than that of the base metal hardness, while Haynes® 282® had a higher hardness in comparison.
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Weldability Study of Superalloys Waspaloy® and Haynes® 282®
2016Co-Authors: Jonny Jacobsson, Joel Andersson, Anssi Brederholm, Hannu HänninenAbstract:The weldability of Waspaloy® and Haynes® 282® have been evaluated using the Varestraint weldability test. The experiments reveal that Waspaloy® has a higher susceptibility to hot cracking compared ...
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Weldability of Ni-Based Superalloys Waspaloy® and Haynes® 282® - A Study Performed with Varestraint Testing
Research & Reviews: Journal of Material Sciences, 2016Co-Authors: Jonny Jacobsson, Joel Andersson, Anssi Brederholm, Hannu HänninenAbstract:There is a need for materials with high strength, oxidation resistance, thermal stability and adequate weldability in order to facilitate the production of large structural jet engine components. Therefore, the weldability of Waspaloy® and Haynes® 282® have been evaluated using the Varestraint weldability test. The experiments reveal that Waspaloy® has a higher susceptibility to hot cracking compared to Haynes® 282®. This conclusion is supported by increased total crack length (10 mm or more) and larger brittle temperature range (approx. 65°C) for Waspaloy® when compared to Haynes® 282® in Varestraint and Gleeble hot ductility tests, respectively. The cracking in Haynes® 282® seems to be connected with a secondary phase which presumably can be associated with Ti-Mo based MC-type carbide observed in the fusion zone. Also, a surrounding segregated area is present near this secondary phase as well as along the grain boundaries. Furthermore, micro-Vickers hardness results revealed more or less the same weld metal hardness (260- 280 HV) but a difference in the base metal hardness. The weld metal hardness of Waspaloy® was lower than that of the base metal hardness, while Haynes® 282® had a higher hardness in comparison.
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8th International Symposium on Superalloy 718 and Derivatives - Solidification of Alloy 718, ATI 718Plus and Waspaloy
2014Co-Authors: Joel Andersson, Shahzad Raza, Anders Eliasson, Kumar Babu SurreddiAbstract:Alloy 718, ATI 718Plus® and Waspaloy have been investigated in terms of what their respective solidification process reveals. Differential thermal analysis was used to approach the task together with secondary electron and back scattered electron detectors equipped with an energy dispersive X-ray spectroscopy detector. These experimental methods were used to construct pseudo binary phase diagrams that could aid in explaining solidification as well as liquation mechanisms in processes such as welding and casting. Furthermore, it was seen that Waspaloy has the smallest solidification range, followed by Alloy 718, and finally ATI 718Plus® possessing the largest solidification interval in comparison.
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solidification of alloy 718 ati 718plus and Waspaloy
8th International Symposium on Superalloy 718 and Derivatives 2014; Pittsburgh; United States; 28 September 2014 through 1 October 2014, 2014Co-Authors: Joel Andersson, Shahzad Raza, Anders Eliasson, Kumar Babu SurreddiAbstract:Alloy 718, ATI 718Plus® and Waspaloy have been investigated in terms of what their respective solidification process reveals. Differential thermal analysis was used to approach the task together with secondary electron and back scattered electron detectors equipped with an energy dispersive X-ray spectroscopy detector. These experimental methods were used to construct pseudo binary phase diagrams that could aid in explaining solidification as well as liquation mechanisms in processes such as welding and casting. Furthermore, it was seen that Waspaloy has the smallest solidification range, followed by Alloy 718, and finally ATI 718Plus® possessing the largest solidification interval in comparison.
X. Wei - One of the best experts on this subject based on the ideXlab platform.
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Experimental study on the machining of a shaped hole in Ni-based super-heat-resistant alloy
Journal of Materials Processing Technology, 2002Co-Authors: X. WeiAbstract:Abstract This paper presents an experimental study on the machining methods for a shaped hole in Ni-based super-heat-resistant alloys Inconel 718 and Waspaloy. The feasibility of using milling or/and grinding as an alternative for the current EDM process to machine shaped holes is assessed by observing the wear and breakage of the cutting tools and grinder and analyzing the hole surface integrity and geometrical accuracy. The results show that the milling process of Inconel 718 and Waspaloy can produce shaped holes with an acceptable surface roughness and geometrical accuracy efficiently, after optimizing the cutting conditions.
Stephen Yue - One of the best experts on this subject based on the ideXlab platform.
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Evolution of flow stress and microstructure during isothermal compression of Waspaloy
Materials Science and Engineering: A, 2014Co-Authors: A. Chamanfar, Mohammad Jahazi, Javad Gholipour, Priti Wanjara, Stephen YueAbstract:Abstract The evolution of the flow stress and microstructure for Waspaloy was studied in the 950–1140 °C temperature range under constant true strain rate conditions of 0.001–1 s −1 up to a true strain of 0.83 using isothermal hot compression testing. The impact of friction at the sample/anvil interface and adiabatic heating during deformation on the flow stress evolution was also examined. Mathematical models relating the flow stress to the deformation temperature and strain rate were derived using a power–law relationship. The strain rate sensitivity and the activation energy for hot deformation of Waspaloy were found to be considerably different for deformation in the subsolvus and supersolvus temperature ranges. According to the microstructural investigations, at 950 °C dynamic recovery (DRV) was the main softening mechanism. By contrast, dynamic recrystallization (DRX), partial or complete, occurred at temperatures above 950 °C and resulted in flow softening.
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Modeling Grain Size and Strain Rate in Linear Friction Welded Waspaloy
Metallurgical and Materials Transactions A, 2013Co-Authors: A. Chamanfar, Mohammad Jahazi, Javad Gholipour, Priti Wanjara, Stephen YueAbstract:The high-temperature deformation behavior of the Ni-base superalloy, Waspaloy, using uniaxial isothermal compression testing was investigated at temperatures above the γ′ solvus, 1333 K, 1373 K, and 1413 K (1060 °C, 1100 °C, and 1140 °C) for constant true strain rates of 0.001, 0.01, 0.1, and 1 s−1 and up to a true strain of 0.83. Flow softening and microstructural investigation indicated that dynamic recrystallization took place during deformation. For the investigated conditions, the strain rate sensitivity factor and the activation energy of hot deformation were 0.199 and 462 kJ/mol, respectively. Constitutive equations relating the dynamic recrystallized grain size to the deformation temperature and strain rate were developed and used to predict the grain size and strain rate in linear friction-welded (LFWed) Waspaloy. The predictions were validated against experimental findings and data reported in the literature. It was found that the equations can reliably predict the grain size of LFWed Waspaloy. Furthermore, the estimated strain rate was in agreement with finite element modeling data reported in the literature.
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Maximizing the integrity of linear friction welded Waspaloy
Materials Science and Engineering: A, 2012Co-Authors: A. Chamanfar, Mohammad Jahazi, Javad Gholipour, Priti Wanjara, Stephen YueAbstract:Abstract The Ni-base superalloy, Waspaloy, was linear friction welded (LFWed) under various processing parameters and then subjected to a post weld heat treatment (PWHT). Tensile testing integrated with the optical image correlation Aramis® system indicated that there is a critical axial shortening value (2 mm) below which LFWed and post weld heat treated (PWHTed) Waspaloy exhibited weak integrity. At and above this critical shortening, the yield strength and ultimate tensile stress (UTS) values were more or less the same as for the parent material. However, total elongation continued to increase with axial shortening even above the critical value due to decrease in width of thermo-mechanically affected zone (TMAZ). The sample with the highest axial shortening (4.9 mm) exhibited an elongation 91% of the parent material elongation. According to Aramis® data, the mixture rule can be used reliably to determine the contribution of TMAZ to the tensile elongation of PWHTed Waspaloy. Microstructure characterization across the weld in the as-LFWed and PWHTed conditions was carried out to correlate the process parameters and microstructural changes that affect the tensile properties. Weak integrity at axial shortening below 2 mm was mainly due to lack of bonding and/or presence of oxides at the weld interface. In the as-welded condition, a loss in hardness was observed, and related to the extensive dissolution of strengthening phase (γ′) in the weld area. The applied PWHT restored the hardness in the weld region.
John A. Gunaraj - One of the best experts on this subject based on the ideXlab platform.
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Erosion behavior of uncoated Waspaloy and Waspaloy coated with titanium carbide
Surface and Coatings Technology, 1997Co-Authors: Vesselin Shanov, Widen Tabakoff, John A. GunarajAbstract:Abstract Turbines and engines operating in a particulate flow environment experience erosion and performance deterioration. The industrial approach for decreasing the erosion of machine components is to apply wear resistance coatings. This paper describes an experimental investigation performed to compare the behavior of uncoated and coated Waspaloy eroded in a media composed of chromite particles. The specimens were coated with titanium carbide (TiC) by a chemical vapor deposition (CVD) technique. The experimental program covered a temperature range from ambient temperature to 538 °C, the particle velocities ranging from 180 m s −1 to 305 m s −1 , and impingement angles varying from 20 ° to 90 °. The facility used for this work was a custom-made, high temperature erosion wind tunnel. The eroded surface morphology was examined by scanning electron microscopy (SEM). The results obtained depict the influence of the temperature, velocity and the impingement angle on the erosion rate. In addition to this, further data show the variation of the coating erosion rate with the quantity of chromite powder used. The erosion rate behavior of the TiC coating with respect to the impingement angles reveals a brittle characteristic trend. The uncoated superalloy behaves as a ductile material because the maximum erosion is between 30 ° and 45 °. It is found that the sample temperature has a significant effect on the material erosion rate. The erosion resistance of the CVD coating increases at elevated temperatures, whereas that of uncoated Waspaloy decreases. The results indicate that the erosion rate for both uncoated and coated samples is proportional to the particle impact velocity to the power n . This investigation showed that the tested CVD titanium carbide coating provides very good erosion protection for Waspaloy in a particulate flow environment at elevated temperatures.
A. Chamanfar - One of the best experts on this subject based on the ideXlab platform.
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Evolution of flow stress and microstructure during isothermal compression of Waspaloy
Materials Science and Engineering: A, 2014Co-Authors: A. Chamanfar, Mohammad Jahazi, Javad Gholipour, Priti Wanjara, Stephen YueAbstract:Abstract The evolution of the flow stress and microstructure for Waspaloy was studied in the 950–1140 °C temperature range under constant true strain rate conditions of 0.001–1 s −1 up to a true strain of 0.83 using isothermal hot compression testing. The impact of friction at the sample/anvil interface and adiabatic heating during deformation on the flow stress evolution was also examined. Mathematical models relating the flow stress to the deformation temperature and strain rate were derived using a power–law relationship. The strain rate sensitivity and the activation energy for hot deformation of Waspaloy were found to be considerably different for deformation in the subsolvus and supersolvus temperature ranges. According to the microstructural investigations, at 950 °C dynamic recovery (DRV) was the main softening mechanism. By contrast, dynamic recrystallization (DRX), partial or complete, occurred at temperatures above 950 °C and resulted in flow softening.
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Modeling Grain Size and Strain Rate in Linear Friction Welded Waspaloy
Metallurgical and Materials Transactions A, 2013Co-Authors: A. Chamanfar, Mohammad Jahazi, Javad Gholipour, Priti Wanjara, Stephen YueAbstract:The high-temperature deformation behavior of the Ni-base superalloy, Waspaloy, using uniaxial isothermal compression testing was investigated at temperatures above the γ′ solvus, 1333 K, 1373 K, and 1413 K (1060 °C, 1100 °C, and 1140 °C) for constant true strain rates of 0.001, 0.01, 0.1, and 1 s−1 and up to a true strain of 0.83. Flow softening and microstructural investigation indicated that dynamic recrystallization took place during deformation. For the investigated conditions, the strain rate sensitivity factor and the activation energy of hot deformation were 0.199 and 462 kJ/mol, respectively. Constitutive equations relating the dynamic recrystallized grain size to the deformation temperature and strain rate were developed and used to predict the grain size and strain rate in linear friction-welded (LFWed) Waspaloy. The predictions were validated against experimental findings and data reported in the literature. It was found that the equations can reliably predict the grain size of LFWed Waspaloy. Furthermore, the estimated strain rate was in agreement with finite element modeling data reported in the literature.
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Maximizing the integrity of linear friction welded Waspaloy
Materials Science and Engineering: A, 2012Co-Authors: A. Chamanfar, Mohammad Jahazi, Javad Gholipour, Priti Wanjara, Stephen YueAbstract:Abstract The Ni-base superalloy, Waspaloy, was linear friction welded (LFWed) under various processing parameters and then subjected to a post weld heat treatment (PWHT). Tensile testing integrated with the optical image correlation Aramis® system indicated that there is a critical axial shortening value (2 mm) below which LFWed and post weld heat treated (PWHTed) Waspaloy exhibited weak integrity. At and above this critical shortening, the yield strength and ultimate tensile stress (UTS) values were more or less the same as for the parent material. However, total elongation continued to increase with axial shortening even above the critical value due to decrease in width of thermo-mechanically affected zone (TMAZ). The sample with the highest axial shortening (4.9 mm) exhibited an elongation 91% of the parent material elongation. According to Aramis® data, the mixture rule can be used reliably to determine the contribution of TMAZ to the tensile elongation of PWHTed Waspaloy. Microstructure characterization across the weld in the as-LFWed and PWHTed conditions was carried out to correlate the process parameters and microstructural changes that affect the tensile properties. Weak integrity at axial shortening below 2 mm was mainly due to lack of bonding and/or presence of oxides at the weld interface. In the as-welded condition, a loss in hardness was observed, and related to the extensive dissolution of strengthening phase (γ′) in the weld area. The applied PWHT restored the hardness in the weld region.
