The Experts below are selected from a list of 18633 Experts worldwide ranked by ideXlab platform
John P. Dear - One of the best experts on this subject based on the ideXlab platform.
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optimisation of process parameters and weld shape of high power yb fibre laser welded 2024 t3 aluminium alloy
Journal of Manufacturing Processes, 2018Co-Authors: L. Chen, John P. Dear, E He, C M DaviesAbstract:Abstract A novel approach to welding crack sensitive 2024 aluminium alloy was made by using fibre laser. Bead on plate welding of 3 mm thick sheets of 2024-T3 was performed to determine the optimum sets of welding parameters including laser power, welding speed, power density and Focal Position, which meet the quality and specification requirements of aircraft structures. A correlation between these parameters and weld shape, microstructure, and defects was found. The weld quality was assessed in terms weld-seam geometry, root to width ratio, surface appearance, penetration depth, microstructure and defects. Microstructural analysis was performed using optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. The parametric optimisation was conducted to obtain crack and porosity free full penetration welds with ideal sized face and root width or weld shape, and a minimal amount of undercut, underfill and reinforcement. While high-quality welds were produced, in some cases, micro-cracks less than 0.5 mm were observed in the weld metal as optimising the parameters only had a limited effect on completely shifting the crack sensitive comPosition. The addition of filler metal with a different chemistry was found to be also necessary to adjust the comPosition to a less crack sensitive range.
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parametric optimisation and microstructural analysis on high power yb fibre laser welding of ti 6al 4v
Optics and Lasers in Engineering, 2016Co-Authors: L. Chen, C M Davies, John P. DearAbstract:Abstract In this work thin sheets of Ti–6Al–4V were full penetration welded using a 5 kW fibre laser in order to evaluate the effectiveness of high power fibre laser as a welding processing tool for welding Ti–6Al–4V with the requirements of the aircraft industry and to determine the effect of welding parameters including laser power, welding speed and beam Focal Position on the weld microstructure, bead profile and weld quality. It involved establishing an understanding of the influence of welding parameters on microstructural change, welding defects, and the characteristics of heat affected zone (HAZ) and weld metal (WM) of fibre laser welded joints. The optimum range of welding parameters which produced welds without cracking and porosity were identified. The influence of the welding parameters on the weld joint heterogeneity was characterised by conducting detailed microstructural analysis.
L. Chen - One of the best experts on this subject based on the ideXlab platform.
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optimisation of process parameters and weld shape of high power yb fibre laser welded 2024 t3 aluminium alloy
Journal of Manufacturing Processes, 2018Co-Authors: L. Chen, John P. Dear, E He, C M DaviesAbstract:Abstract A novel approach to welding crack sensitive 2024 aluminium alloy was made by using fibre laser. Bead on plate welding of 3 mm thick sheets of 2024-T3 was performed to determine the optimum sets of welding parameters including laser power, welding speed, power density and Focal Position, which meet the quality and specification requirements of aircraft structures. A correlation between these parameters and weld shape, microstructure, and defects was found. The weld quality was assessed in terms weld-seam geometry, root to width ratio, surface appearance, penetration depth, microstructure and defects. Microstructural analysis was performed using optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. The parametric optimisation was conducted to obtain crack and porosity free full penetration welds with ideal sized face and root width or weld shape, and a minimal amount of undercut, underfill and reinforcement. While high-quality welds were produced, in some cases, micro-cracks less than 0.5 mm were observed in the weld metal as optimising the parameters only had a limited effect on completely shifting the crack sensitive comPosition. The addition of filler metal with a different chemistry was found to be also necessary to adjust the comPosition to a less crack sensitive range.
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parametric optimisation and microstructural analysis on high power yb fibre laser welding of ti 6al 4v
Optics and Lasers in Engineering, 2016Co-Authors: L. Chen, C M Davies, John P. DearAbstract:Abstract In this work thin sheets of Ti–6Al–4V were full penetration welded using a 5 kW fibre laser in order to evaluate the effectiveness of high power fibre laser as a welding processing tool for welding Ti–6Al–4V with the requirements of the aircraft industry and to determine the effect of welding parameters including laser power, welding speed and beam Focal Position on the weld microstructure, bead profile and weld quality. It involved establishing an understanding of the influence of welding parameters on microstructural change, welding defects, and the characteristics of heat affected zone (HAZ) and weld metal (WM) of fibre laser welded joints. The optimum range of welding parameters which produced welds without cracking and porosity were identified. The influence of the welding parameters on the weld joint heterogeneity was characterised by conducting detailed microstructural analysis.
C M Davies - One of the best experts on this subject based on the ideXlab platform.
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optimisation of process parameters and weld shape of high power yb fibre laser welded 2024 t3 aluminium alloy
Journal of Manufacturing Processes, 2018Co-Authors: L. Chen, John P. Dear, E He, C M DaviesAbstract:Abstract A novel approach to welding crack sensitive 2024 aluminium alloy was made by using fibre laser. Bead on plate welding of 3 mm thick sheets of 2024-T3 was performed to determine the optimum sets of welding parameters including laser power, welding speed, power density and Focal Position, which meet the quality and specification requirements of aircraft structures. A correlation between these parameters and weld shape, microstructure, and defects was found. The weld quality was assessed in terms weld-seam geometry, root to width ratio, surface appearance, penetration depth, microstructure and defects. Microstructural analysis was performed using optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. The parametric optimisation was conducted to obtain crack and porosity free full penetration welds with ideal sized face and root width or weld shape, and a minimal amount of undercut, underfill and reinforcement. While high-quality welds were produced, in some cases, micro-cracks less than 0.5 mm were observed in the weld metal as optimising the parameters only had a limited effect on completely shifting the crack sensitive comPosition. The addition of filler metal with a different chemistry was found to be also necessary to adjust the comPosition to a less crack sensitive range.
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The effect of Ar and He shielding gas on fibre laser weld shape and microstructure in AA 2024-T3
'Elsevier BV', 2017Co-Authors: Ahn J, He E, Chen L, Jp Dear, C M DaviesAbstract:The effect of using argon and helium shielding gas on weld quality, defect formation and microstructure of laser welded aluminium alloy 2024-T3 was investigated. Full penetration autogenous welds were made at a constant laser power of 4.9 kW using a continuous-wave (CW) fibre laser at travel speeds of 3.0–5.0 m/min and Focal Positions of +4 to −4 mm. To investigate this effect, a comparison was made between Ar and He by examining the weld quality in terms of the face and root weld width, the weld width ratio; and the presence of welding defects including undercut, underfill, reinforcement, porosity and crack. Optical metallography, energy-dispersive X-ray spectroscopy and micro-hardness indentation testing on weld cross-sections were used to identify how the chemical and physical properties of the shielding gases and the characteristics of the fibre laser affect the overall weld geometry. Based on the results, it was believed that relatively small influence of ionisation on fibre laser induced plume enhanced the welding process stability and lowered the threshold power density for keyhole formation. Both Ar and He shielding gases could therefore, be used effectively to produce good quality welds. However, at the lowest speed and also at the maximum Focal Position, higher ionisation potential and thermal conductivity of helium resulted in an excessive weld width when He was used even though, the overall weld quality was better than that with Ar
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parametric optimisation and microstructural analysis on high power yb fibre laser welding of ti 6al 4v
Optics and Lasers in Engineering, 2016Co-Authors: L. Chen, C M Davies, John P. DearAbstract:Abstract In this work thin sheets of Ti–6Al–4V were full penetration welded using a 5 kW fibre laser in order to evaluate the effectiveness of high power fibre laser as a welding processing tool for welding Ti–6Al–4V with the requirements of the aircraft industry and to determine the effect of welding parameters including laser power, welding speed and beam Focal Position on the weld microstructure, bead profile and weld quality. It involved establishing an understanding of the influence of welding parameters on microstructural change, welding defects, and the characteristics of heat affected zone (HAZ) and weld metal (WM) of fibre laser welded joints. The optimum range of welding parameters which produced welds without cracking and porosity were identified. The influence of the welding parameters on the weld joint heterogeneity was characterised by conducting detailed microstructural analysis.
P Sathiya - One of the best experts on this subject based on the ideXlab platform.
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parameter design and analysis in laser welding of nitinol shape memory alloy
Materials Today: Proceedings, 2017Co-Authors: Deepan Bharathi T Kannan, Abhijeet R Shegokar, P Sathiya, T RameshAbstract:Abstract This article presents a study on Ytterbium: Yttrium aluminium garnet (Yb: YAG) laser welding of NiTinol shape memory alloys. NiTinol belongs to a class of smart materials. In recent days, due to its unique properties namely shape memory effect, biocompatibility and superelasticity it is finding wide range of applications in the field of automotive, aerospace, fashion, and biomedical industries. Bead on plate welding was done on NiTinol sheets based on L9 taguchi design with welding speed, laser power, Focal Position and shielding gas blown angle as input parameters. Bead geometry (Bead width, depth of penetration), hardness were measured as performance characteristics. Technique for order of preference by ideal solution (TOPSIS) was employed for multi performance characteristics optimization and metallurgical aspects of the weld with highest relative closeness value are also discussed.
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metallurgical aspects and optimisation of yb yag laser welded nitinol shape memory alloy
Materials Today: Proceedings, 2017Co-Authors: Deepan Bharathi T Kannan, P Sathiya, Pavani T Priya, T RameshAbstract:Abstract This article presents a study on optimization of multi performance characteristics using grey relational analysis (GRA) in laser welding of NiTinol shape memory alloys. Bead on plate welding was done on NiTinol plates of 1 mm thickness using Ytterbium: Yttrium aluminium garnet (Yb: YAG) laser welding process. The experiment was carried out on the basis of Taguchi L9 Design with welding speed, Shielding gas blown distance, Focal Position and power as input parameters. Bead geometry (Depth of penetration, bead width) and microhardness were measured as performance characteristics. Analysis of variance (ANOVA) was utilized for calculating individual parameter percentage contribution on the multi performance characteristics. It was found that welding speed as the most influential parameter on the multi performance characteristics followed by shielding gas blown distance, power and Focal Position. The metallurgical aspects of the optimized weld are also discussed with help of microstructure.
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optimisation of laser welding parameters for welding of p92 material using taguchi based grey relational analysis
Defence Technology, 2016Co-Authors: B Shanmugarajan, P Sathiya, Rishabh Shrivastava, G BuvanashekaranAbstract:Abstract Creep strength enhanced ferritic (CSEF) steels are used in advanced power plant systems for high temperature applications. P92 (Cr–W–Mo–V) steel, classified under CSEF steels, is a candidate material for piping, tubing, etc., in ultra-super critical and advanced ultra-super critical boiler applications. In the present work, laser welding process has been optimised for P92 material by using Taguchi based grey relational analysis (GRA). Bead on plate (BOP) trials were carried out using a 3.5 kW diffusion cooled slab CO2 laser by varying laser power, welding speed and Focal Position. The optimum parameters have been derived by considering the responses such as depth of penetration, weld width and heat affected zone (HAZ) width. Analysis of variance (ANOVA) has been used to analyse the effect of different parameters on the responses. Based on ANOVA, laser power of 3 kW, welding speed of 1 m/min and Focal plane at −4 mm have evolved as optimised set of parameters. The responses of the optimised parameters obtained using the GRA have been verified experimentally and found to closely correlate with the predicted value.
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optimal design for laser beam butt welding process parameter using artificial neural networks and genetic algorithm for super austenitic stainless steel
Optics and Laser Technology, 2012Co-Authors: P Sathiya, K Panneerselvam, R SoundararajanAbstract:Abstract Laser welding input parameters play a very significant role in determining the quality of a weld joint. The joint quality can be defined in terms of properties such as weld bead geometry, mechanical properties and distortion. Therefore, mechanical properties should be controlled to obtain good welded joints. In this study, the weld bead geometry such as depth of penetration (DP), bead width (BW) and tensile strength (TS) of the laser welded butt joints made of AISI 904L super austenitic stainless steel were investigated. Full factorial design was used to carry out the experimental design. Artificial Neural networks (ANN) program was developed in MatLab software to establish the relationships between the laser welding input parameters like beam power, travel speed and Focal Position and the three responses DP, BW and TS in three different shielding gases (Argon, Helium and Nitrogen). The established models were used for optimizing the process parameters using Genetic Algorithm (GA). Optimum solutions for the three different gases and their respective responses were obtained. Confirmation experiment has also been conducted to validate the optimized parameters obtained from GA.
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optimization of laser welding process parameters for super austenitic stainless steel using artificial neural networks and genetic algorithm
Materials & Design, 2012Co-Authors: P Sathiya, K Panneerselvam, M Abdul Y JaleelAbstract:Abstract The laser welding input parameters play a very significant role in determining the quality of a weld joint. The quality of the joint can be defined in terms of properties such as weld bead geometry, mechanical properties and distortion. In particular mechanical properties should be controlled to obtain good welded joints. In this study, the weld bead geometry such as depth of penetration (DP), bead width (BW) and tensile strength (TS) of the laser welded butt joints made of AISI 904L super austenitic stainless steel are investigated. Full factorial design is used to carry out the experimental design. Artificial neural networks (ANNs) program was developed in MatLab software to establish the relationship between the laser welding input parameters like beam power, travel speed and Focal Position and the three responses DP, BW and TS in three different shielding gases (argon, helium and nitrogen). The established models are used for optimizing the process parameters using genetic algorithm (GA). Optimum solutions for the three different gases and their respective responses are obtained. Confirmation experiment has also been conducted to validate the optimized parameters obtained from GA.
M Abdul Y Jaleel - One of the best experts on this subject based on the ideXlab platform.
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optimization of laser welding process parameters for super austenitic stainless steel using artificial neural networks and genetic algorithm
Materials & Design, 2012Co-Authors: P Sathiya, K Panneerselvam, M Abdul Y JaleelAbstract:Abstract The laser welding input parameters play a very significant role in determining the quality of a weld joint. The quality of the joint can be defined in terms of properties such as weld bead geometry, mechanical properties and distortion. In particular mechanical properties should be controlled to obtain good welded joints. In this study, the weld bead geometry such as depth of penetration (DP), bead width (BW) and tensile strength (TS) of the laser welded butt joints made of AISI 904L super austenitic stainless steel are investigated. Full factorial design is used to carry out the experimental design. Artificial neural networks (ANNs) program was developed in MatLab software to establish the relationship between the laser welding input parameters like beam power, travel speed and Focal Position and the three responses DP, BW and TS in three different shielding gases (argon, helium and nitrogen). The established models are used for optimizing the process parameters using genetic algorithm (GA). Optimum solutions for the three different gases and their respective responses are obtained. Confirmation experiment has also been conducted to validate the optimized parameters obtained from GA.
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influence of shielding gas mixtures on bead profile and microstructural characteristics of super austenitic stainless steel weldments by laser welding
The International Journal of Advanced Manufacturing Technology, 2011Co-Authors: P Sathiya, M Abdul Y JaleelAbstract:A planned and orderly analysis of the microstructures and bead profiles of AISI 904 L super austenitic stainless steel bead-on-plate welds was accomplished by coupling up diffusion cooled slab 3.5 kW CO2 laser with two dissimilar shielding gaseous mixture namely 100% nitrogen (N) and 50% argon + 50% nitrogen (A + N). AISI 904 L Super Austenitic Stainless Steel (SASS) incorporates higher levels of Mo, Cr, Ni, N, and Mn under normal conditions. In heating applications, it offers a superior corrosion resistance at moderate and higher temperatures. The microstructure of SASS is exhaustively austenitic in nature, when subjected to a solution-quenched state. The objective of this study is to determine the phenomenon that follows the action of two shielding gas mixtures on microstructural and bead profiles of laser-welded 904 L SASS. The weld bead profile of laser welding depends on various parameters such as beam power; travel speed, and Focal Position of the laser spot, and these factors have to be chosen in an appropriate manner to obtain the desired output. The cross-sectioned area of the bead profiles like bead width and depth of penetration is measured using an optical microscope. Two different shielding gas mixtures were used to examine the microstructural changes in the weld region. Besides, the variation in the hardness of the weld region was analyzed through the Vickers hardness tester.