The Experts below are selected from a list of 72 Experts worldwide ranked by ideXlab platform
Xiaochun Li - One of the best experts on this subject based on the ideXlab platform.
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nanoparticle enabled phase control for arc welding of unweldable aluminum alloy 7075
Nature Communications, 2019Co-Authors: Maximilian Sokoluk, Xiaochun LiAbstract:Lightweight materials are of paramount importance to reduce energy consumption and emissions in today’s society. For materials to qualify for widespread use in lightweight structural assembly, they must be weldable or joinable, which has been a long-standing issue for high strength aluminum alloys, such as 7075 (AA7075) due to their hot crack susceptibility during fusion welding. Here, we show that AA7075 can be safely arc welded without hot cracks by intRoducing nanoparticle-enabled phase control during welding. Joints welded with an AA7075 Filler Rod containing TiC nanoparticles not only exhibit fine globular grains and a modified secondary phase, both which intrinsically eliminate the materials hot crack susceptibility, but moreover show exceptional tensile strength in both as-welded and post-weld heat-treated conditions. This rather simple twist to the Filler material of a fusion weld could be generally applied to a wide range of hot crack susceptible materials. In contrast to steels, fusion welding high strength aluminum alloys such as AA7075 is notoriously difficult. Here, the authors add nanoparticles to a weld Filler Rod to successfully weld AA7075 without hot cracks or loss of strength at the weld.
Maximilian Sokoluk - One of the best experts on this subject based on the ideXlab platform.
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nanoparticle enabled phase control for arc welding of unweldable aluminum alloy 7075
Nature Communications, 2019Co-Authors: Maximilian Sokoluk, Xiaochun LiAbstract:Lightweight materials are of paramount importance to reduce energy consumption and emissions in today’s society. For materials to qualify for widespread use in lightweight structural assembly, they must be weldable or joinable, which has been a long-standing issue for high strength aluminum alloys, such as 7075 (AA7075) due to their hot crack susceptibility during fusion welding. Here, we show that AA7075 can be safely arc welded without hot cracks by intRoducing nanoparticle-enabled phase control during welding. Joints welded with an AA7075 Filler Rod containing TiC nanoparticles not only exhibit fine globular grains and a modified secondary phase, both which intrinsically eliminate the materials hot crack susceptibility, but moreover show exceptional tensile strength in both as-welded and post-weld heat-treated conditions. This rather simple twist to the Filler material of a fusion weld could be generally applied to a wide range of hot crack susceptible materials. In contrast to steels, fusion welding high strength aluminum alloys such as AA7075 is notoriously difficult. Here, the authors add nanoparticles to a weld Filler Rod to successfully weld AA7075 without hot cracks or loss of strength at the weld.
Intan Fadhlina Mohamed - One of the best experts on this subject based on the ideXlab platform.
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study and selection of most appropriate Filler Rod for gtaw of s32750 super duplex steel joints a comprehensive study on microstructural mechanical and corrosion properties
Materials Chemistry and Physics, 2021Co-Authors: Esmaeil Amiri, Farhad Ostovan, Meysam Toozandehjani, Ehsan Shafiei, Intan Fadhlina MohamedAbstract:Abstract In the present study, the effect of using different Filler metals on the microstructure, mechanical and corrosion properties of gas tungsten arc welding (GTAW) of S32750 super duplex steel joints has been investigated. Three different Filler Rods of 316 L, S32202, and S32750 containing different concentrations of ferrite and austenite stabilizer elements were used to fabricate GTAW S32750 joints. From the microstructural studies, it was found that elongated structure of austenitic-ferritic transforms into a dendritic γ-austenite structure within an α-ferrite matrix, when S32202 and S32750 were used. While, the microstructure of sample welded by 316 L was consisted of dendritic δ-ferrite phase in the austenite grain boundaries. Owning the higher percentage of α-ferrite phase, the sample welded by S32202 Filler Rod showed the highest microhardness and tensile strength. The best combination of tensile strength (826 MPa), ductility (27%) and absorbed energy prior to fracture (51 J) was observed in the sample welded by S32750 Filler Rod due to the higher percentage of γ-austenite phase or a decrease in the percentage of the α and δ-ferrite phase in the weld microstructure. The Tafel polarization test showed that the highest and lowest corrosion resistance belonged to the samples welded by S32750 and 316 L, respectively. The presence of higher percentage of γ-austenite phase caused an increase in the corrosion resistance of the weld metal, while the presence of higher percentage of α and δ-ferrite caused a significant decrease in the corrosion resistance.
A H Kokabi - One of the best experts on this subject based on the ideXlab platform.
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study on microstructure and mechanical characteristics of low carbon steel and ferritic stainless steel joints
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2014Co-Authors: Mahmoud Sarkari Khorrami, M A Mostafaei, Hesam Pouraliakbar, A H KokabiAbstract:Abstract In this work, examinations on the microstructure and mechanical properties of plain carbon steel and AISI 430 ferritic stainless steel dissimilar welds are carried out. Welding is conducted in both autogenous and using ER309L austenitic Filler Rod conditions through gas tungsten arc welding process. The results indicate that fully-ferritic and duplex ferritic–martensitic microstructures are formed for autogenous and Filler-added welds, respectively. Carbide precipitation and formation of martensite at ferrite grain boundaries (intergranular martensite) as well as grain growth occur in the heat affected zone (HAZ) of AISI 430 steel. It is found that weld heat input can strongly affect grain growth phenomenon along with the amount and the composition of carbides and intergranular martensite. Acquired mechanical characteristics of weld in the case of using Filler metal are significantly higher than those of autogenous one. Accordingly, ultimate tensile strength (UTS), hardness, and absorbed energy during tensile test of weld metal are increased from 662 MPa to 910 MPa, 140 Hv to 385 Hv, and 53.6 J m −3 to 79 J m −3 , respectively by Filler metal addition. From fracture surfaces, predominantly ductile fracture is observed in the specimen welded with Filler metal while mainly cleavage fracture occurs in the autogenous weld metal.
Esmaeil Amiri - One of the best experts on this subject based on the ideXlab platform.
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study and selection of most appropriate Filler Rod for gtaw of s32750 super duplex steel joints a comprehensive study on microstructural mechanical and corrosion properties
Materials Chemistry and Physics, 2021Co-Authors: Esmaeil Amiri, Farhad Ostovan, Meysam Toozandehjani, Ehsan Shafiei, Intan Fadhlina MohamedAbstract:Abstract In the present study, the effect of using different Filler metals on the microstructure, mechanical and corrosion properties of gas tungsten arc welding (GTAW) of S32750 super duplex steel joints has been investigated. Three different Filler Rods of 316 L, S32202, and S32750 containing different concentrations of ferrite and austenite stabilizer elements were used to fabricate GTAW S32750 joints. From the microstructural studies, it was found that elongated structure of austenitic-ferritic transforms into a dendritic γ-austenite structure within an α-ferrite matrix, when S32202 and S32750 were used. While, the microstructure of sample welded by 316 L was consisted of dendritic δ-ferrite phase in the austenite grain boundaries. Owning the higher percentage of α-ferrite phase, the sample welded by S32202 Filler Rod showed the highest microhardness and tensile strength. The best combination of tensile strength (826 MPa), ductility (27%) and absorbed energy prior to fracture (51 J) was observed in the sample welded by S32750 Filler Rod due to the higher percentage of γ-austenite phase or a decrease in the percentage of the α and δ-ferrite phase in the weld microstructure. The Tafel polarization test showed that the highest and lowest corrosion resistance belonged to the samples welded by S32750 and 316 L, respectively. The presence of higher percentage of γ-austenite phase caused an increase in the corrosion resistance of the weld metal, while the presence of higher percentage of α and δ-ferrite caused a significant decrease in the corrosion resistance.