Kyushu University · Materials Science
Professor Yongpeng Tang's research lab specializes in advanced processing and microstructure engineering of lightweight aluminum alloys, with a focus on severe plastic deformation techniques such as high-pressure torsion (HPT), high-pressure sliding (HPS), and accumulative roll bonding (ARB). The lab investigates grain refinement, dislocation dynamics, and precipitation hardening to enhance mechanical properties like tensile strength, ductility, and superplasticity. Key research directions include the development of ultrafine-grained and nanocrystalline aluminum alloys with tailored microstructures for high-performance structural applications.
Figures are computed from collected data and may differ slightly.
To investigate the effect of high-density electric current on the delay of fatigue crack initiation, the dislocation structures before and after the application of electric current were investigated by transmission electron microscopy. Dislocation density was quantitatively characterized before and after the application of electric current to further understand the mechanics of the healing effect. Atomic force microscope results showed that the slips disappeared locally and the slip height decre
In this study, A6022-based Al–Mg–Si alloys with three additional Fe contents are processed by high-pressure torsion (HPT) and high-pressure sliding (HPS). Both processes yield a similar tensile strength exceeding 400 MPa. Fe intermetallics were finely and homogeneously fragmented to an average size of ∼2 µm by the HPT process. The high tensile strength is attributed to such a fine and homogeneous fragmentation of Fe intermetallics. It is also demonstrated that the finely fragmented Fe intermetal
The high-pressure sliding (HPS) process was applied for grain refinement of a pipe form of an Al-3wt%Mg-0.2wt%Sc alloy by developing two types of straining techniques (called in this study anvil sliding and mandrel sliding). To achieve a homogeneous microstructure throughout the cross-section of the pipe, the sample is rotated around the longitudinal axis every after sliding operation by introducing multi-pass technique, named multi-pass HPS (MP-HPS) as developed earlier for rods. The MP-HPS-pro
In this study, the multi-pass high-pressure sliding (MP-HPS) process was applied for grain refinement of Al–3Mg–0.2Sc (mass%) rods with an upsized dimension of 16 mm in diameter. To achieve a homogeneous microstructure throughout the cross-section, the rod sample was rotated with 60° around the longitudinal axis (MP-HPS-R) for three times. A microstructure with an average grain size of 280 nm was developed around the center of the cross-section through the MP-HPS-R process. Superplasticity with
Herein, the age‐hardening behavior of the severely deformed and then artificially aged A2099 Al–Li–Cu alloy is investigated by Vickers hardness test, tensile test, and transmission electron microscopy (TEM). The combined processes of accumulative roll bonding (ARB) and aging treatment at 373 K for 2419 ks result in the highest hardness (≈190 HV) for the 5‐cycled ARB sample with an age hardenability of 37 ± 2 HV. For the 2‐cycled ARB sample with aging treatment, the ultimate tensile strength and
This study presents that A1050 commercial-purity aluminum increases the tensile strength and ductility using the processes of accumulative roll bonding (ARB) and high-pressure sliding (HPS). Both processes yield a similar tensile strength exceeding 240 MPa after processing by ARB for 10 cycles and by HPS for the sliding distance of 15 mm, respectively. The stress-strain behavior is evaluated through microstructure observations and measurements of strain hardening rates. Significant grain refinem
In this study, the multi-pass high-pressure sliding (MP-HPS) process was applied for grain refinement of Al–3Mg–0.2Sc (mass%) rods with an upsized dimension of 16 mm in diameter. To achieve a homogeneous microstructure throughout the cross-section, the rod sample was rotated with 60° around the longitudinal axis (MP-HPS-R) for three times. A microstructure with an average grain size of 280 nm was developed around the center of the cross-section through the MP-HPS-R process. Superplasticity with
Open papers in the app to read, cite, and organize with AI.
