| Masatoshi Aramaki | Last modified date：2024.04.18 |
Assistant Professor /
Material Science and Engineering /
Department of Materials Science and Engineering /
Faculty of Engineering
Presentations
| 1. | Analysis of anisotropy fracture during Bulge forming in Inconel Alloy. |
| 2. | Yukiko Ozaki, Isshin Ando, Yasutaka Mugita, Kyosuke Hirayama, Masatoshi Aramaki, Fei Jiang, Takeshi Tsuji, Akihisa Takeuchi, Masayuki Uesugie, Kosuke Ashizuka, Understanding crack initiation and growing process in sintered iron by applying the 0th persistent homology on the snapshots of 3D CT pore images during tensile tests, The Advanced Technology in Experimental Mechanics and International DIC Society Joint Conference 2023 (ATEM-iDICs '23), 2023.10, [URL], To improve the mechanical properties sintered parts, it is necessary to clarify the effect of the large number of pores on crack initiation. To solve this problem, accurate understanding of the 3D pore configuration by X-ray computed tomography (CT) is useful. In this study, we traced the change of pore configurations during tensile testing with 3D CT observations and furthermore tried to distinguish the roles of open and closed pores using Persistent Homology (PH) in the process of ductile crack initiation.. |
| 3. | Quantitative analysis of three-dimensional pore arrangement in L-PBF material using X-ray CT. |
| 4. | Takeshi Higaki, Yuji Shigeta, Ryotaro Kusunoki, Naoyuki Nomura, Masatoshi Aramaki, Yukiko Ozaki, Evaluation of periodicity in 3D defect distribution in additive manufactured Ti using Persistent Homology, International Conference on Powder and Powder Metallurgy, 2023.10, [URL], The structural defects in L-PBF metals, such as residual-unmelted pores or spherical bubbles have been reported as the structural factors resulting in an anisotropy or variation in mechanical strength. For the practical application of the L PBF metals, it is an essential matter to improve the reliability of mechanical strength by clarifying the mutual relationships among process parameters, structural configuration of the defects and their mechanical properties. From this view point, we attempted to clarify the specific configurations of the defects by applying the persistent holography (PH) on high brilliance X ray CT images of L-PBF Ti .. |
| 5. | Effect of defects on plastic deformation of LPBF CP-Ti. |
| 6. | Periodic analysis of internal pores in pure Ti L-PBF material in the building direction. |
| 7. | Identification of 3D defect arrangement related to ductile crack initiation in Ti-AM material by persistent homology. |
| 8. | Effect of Precipitation Particles on Strengthening Amount of Martensitic Precipitation Hardening Stainless Steels. |
| 9. | Characteristic Fracture in Bulge Forming of Inconel Alloy. |
| 10. | In-situ observation of three-dimensional structural changes associated with ductile fracture of titanium additive manufacturing materials. |
| 11. | Numerical Analysis of Laminate Structure of Ti AM Materials by Persistent Homology. |
| 12. | Wear resistance of Fe-Cr sintered and vacuum carburized materials. |
| 13. | Yuji Shigeta, Masatoshi Aramaki, Kentaro Kudo, Kazunari Shinagawa, Naoyuki Nomura, Katsuyoshi Kondoh, Masato Hoshino, Kentaro Uesugi, Yukiko Ozaki, Understanding the effect of process parameters on three-dimensional pore configurations and mechanical properties of laser additive manufactured Ti using synchrotron X-ray computed tomography and homology, World PM2022 Congress, 2022.10, [URL], Three-dimensional (3D) pore configurations were visualized using synchrotron X-ray computed tomography (CT), and persistent homology (PH) in addition to imaging analysis about additive-manufactured titanium (AM-Ti) specimens, prepared by different laser power and scanning speeds. The highest density was obtained at the middle of the laser energy density as a function of process parameters, such as the laser power and scanning speed. In the lower energy density, large irregular pores were observed along to the scanning directions. On the other hand, smaller round shaped pores due to balling phenomena generated in the higher energy density. These morphological parameters and the 3D configurations of pores will be quantitatively discussed in relation to process parameters and tensile strength. sintered pure iron, Acetylene (C2H2) gas carburizing, wear resistance, nano-indentation hardness The wear resistance without lubrication of sintered pure iron treated by vacuum carburizing process was investigated. The sliding test results revealed that the wear volume of the specimen treated by the C2H2 gas carburizing decreased about 75% in comparison with the one without the heat treatment. The wear profile observation by Laser microscope of friction surface for the specimen treated by the C2H2 gas carburizing was seemed to be a relatively shallow. In contrast, in specimen without the heat treatment, the relatively deep valley was observed. In addition, a micro-ploughing track and relatively deep scar parallel to the sliding direction which is the characteristic of abrasive wear were observed in the specimen without the heat treatment. Nano-indentation hardness at near the surface of the specimen treated the C2H2 gas carburizing increased from value of HIT amounted to 1751 N/mm2 before heat treatment to 7699 N/mm2 after the heat treatment. The EBSD analysis results showed that the carburized layer consisted of a tempered martensitic phase and a small amount of a retained austenite phase. From these results, it can be concluded that the enhanced wear resistance of the C2H2 gas carburizing specimen is attributed to the increase in the hardness due to the presence of the martensitic phase layer at the surface. This layer is considered to inhibit the surface degradation due to micro-ploughing or exfoliation resulting in a high wear rate.. |
| 14. | Change of 3D pore configurations in Ti additive-manufactured material at tensile test. |
| 15. | Effect of 3D Structural Defects on Tensile Strength in Additive Manufactured Ti. |
| 16. | Effect of laser process parameters on three-dimensional structural defects formation of laser additive-manufactured titanium. |
| 17. | Effect of carburized atmosphere on mechanical strengths of Fe-Cr sintered material. |
| 18. | Effect of Cu addition on improving deep drawing formability of γ stainless steels. |
| 19. | Effect of carburizing atmosphere on fatigue strength of Fe-Cr-based sintered / carburized material. |
| 20. | Effect of carburizing atmosphere on wear resistance of Fe-Cr-based sintered / carburized material. |
| 21. | Effect of cooling rate on Mechanical Properties of Fe-3%Cu-0.7%C Sintered Steels using Cu HybridAlloyed Steel Powder. |
| 22. | Effect of networked Cu-rich ferrite phase on mechanical properties of sintered bodies of Fe-3%Cu-0.7%C. |
| 23. | Controlling factor for deep drawability of Cu added stainless steel. |
| 24. | Wear resistance mechanism of sintered pure iron with carburized or Nitrogen quenching. |
| 25. | Ductile Fracture Behavior of High-density sintered pure Fe obtained by Hot Isostatic Pressing. |
| 26. | Effect of Pore Configurations on Crack Initiation during Tensile Deformation of High-Density Sintered Pure Iron. |
| 27. | Influence of Cu localization on mechanical properties of Fe-3%Cu-0.7%C sintered compact . |
| 28. | Effect of welding heat on void formation-growth of S-doped γ stainless steel. |
| 29. | Elucidation of rotary bending fatigue characteristics of acetylene-added gas carburized SCM 415. |
| 30. | Ozaki, Y; Mugita, Y; Aramaki, M; Furukimi, O (Kyushu University,Japan); Ashizuka, K (JFE Steel Corporation, Japan); Takeuchi, A; Uesugi, M (Japan Synchrotron Radiation Research Institute (JASRI), Japan), Four-dimensional (4D) Observation Of Ductile Fracture In Sintered Iron Using Synchrotron X-ray, European Powder Metallurgy Association (EURO PM 2018), 2018.10, [URL], Synchrotron X-ray laminography was used to reveal the time evolution of the three-dimensional (3D) morphology of micropores in sintered iron during a tensile test. 3D snapshots showed networked open pores growing wider than 20 μm along the tensile direction, resulting in internal necking of the specimen. Finally, these pores initiated cracks perpendicular to the tensile direction by coalescing with surrounding preexisting microvoids or secondary-generated voids immediately before fracture. Topological analysis of the barycentric positions of these microvoids showed that they formed two-dimensional networks within a ~20 μm-radius area. This indicates that microvoid coalescence could occur on shear planes formed close to the enlarged open pores or between closed pores by strain accumulation and play an important role in crack initiation.. |
| 31. | Effect of S content on Heat Affected Zone in austenitic stainless steels.. |
| 32. | Wear resistant mechanism of pure sintered iron treated with carburizing/nitriding and quenching process. |
| 33. | Three-dimensional (3D) Observation of pores in sintered iron under tensile stress using Synchrotron X-ray Laminography. |
| 34. | Kiattisaksri Chatcharit, Masaki Tanaka, Masatoshi Aramaki, Osamu Furukimi, Satoshi Oue, Shinji Munetoh, Yuji Takeda, Void nucleation behavior of single-crystal high-purity iron specimens subjected to tensile deformation, Advances in Engineering, 2018.02, [URL], The researchers initiated their experiment by selecting two micrometer-size single crystals having a different type of slip extracted from electro-deposited pure iron for use to investigate the fracture mechanics during tensile deformation. The team then applied high voltage electron microscopy imagery and scanning electron microscopy technique to verify the existence of only one single slip system in the smaller specimen while still checking out for voids. A similar procedure was then carried out for the larger specimen. The research team was able to observe that the smaller specimen exhibited straight slip patterns while for the larger specimens, a number of shear bands and wavy slip patterns were observed. The researchers also noticed the nucleation behavior of voids in single-crystal iron specimens. It was observed that voids with diameters of 50–100 nm were present along the slip band in the larger specimen.. |
| 35. | Three-dimensional (3D) Observation of pores in sintered iron under tensile stress using Synchrotron X-ray Laminography. |
| 36. | Muhammad Kozin, Naoya Yamada, Masatoshi Aramaki, Ozaki Yukiko, Osamu Furukimi, Wear Resistance of Sintered Pure Iron Treated by Acetylene Gas Carburizing Process, JSPM International Conference on Powder and Powder Metallurgy, 2017.11, [7A-A2] Sintering and Post Processing Oral presentation Tue. Nov 7, 2017 5:30 PM - 6:30 PM Room A (1F, Centennial Hall) Chairperson: Hideaki MATSUBARA (Tohoku University, Japan), Chairperson: Katsuyoshi KONDOH (Osaka University, Japan) [7A-A2-03]Wear Resistance of Sintered Pure Iron Treated by Acetylene Gas Carburizing Process 6:10 PM - 6:30 PM *Muhammad Kozin1,2, Naoya Yamada3, Masatoshi Aramaki1, Yukiko Ozaki1, Osamu Furukimi1 （1. Department of Materials Science and Engineering, Kyushu University(Japan), 2. Agency for the Assessment and Application of Technology(Indonesia), 3. Nihon Techno Corporation Limited(Japan)） sintered pure iron, Acetylene (C2H2) gas carburizing, wear resistance, nano-indentation hardness The wear resistance without lubrication of sintered pure iron treated by vacuum carburizing process was investigated. The sliding test results revealed that the wear volume of the specimen treated by the C2H2 gas carburizing decreased about 75% in comparison with the one without the heat treatment. The wear profile observation by Laser microscope of friction surface for the specimen treated by the C2H2 gas carburizing was seemed to be a relatively shallow. In contrast, in specimen without the heat treatment, the relatively deep valley was observed. In addition, a micro-ploughing track and relatively deep scar parallel to the sliding direction which is the characteristic of abrasive wear were observed in the specimen without the heat treatment. Nano-indentation hardness at near the surface of the specimen treated the C2H2 gas carburizing increased from value of HIT amounted to 1751 N/mm2 before heat treatment to 7699 N/mm2 after the heat treatment. The EBSD analysis results showed that the carburized layer consisted of a tempered martensitic phase and a small amount of a retained austenite phase. From these results, it can be concluded that the enhanced wear resistance of the C2H2 gas carburizing specimen is attributed to the increase in the hardness due to the presence of the martensitic phase layer at the surface. This layer is considered to inhibit the surface degradation due to micro-ploughing or exfoliation resulting in a high wear rate. . |
| 37. | Keisuke Watanabe, Hirofumi Ide, Morihiko Nakasaki, Akihisa Takeuchi, Masatoshi Aramaki, Osamu Furukimi, The study of porosity closure during hot compression of steels by applying synchrotron X-ray laminography and FEM analysis, EMRS (European Materials Research Society), 2017.09, Center porosities due to solidification contraction during continuous or ingot casting could remain, ever after bar rolling and forging. To eliminate these defective porosities, it is effective to minimize the porosity generation during casting and to close them by optimizing the plastic forming conditions such as rolling and forging. Numerical analysis and experimental verification are used for optimizing plastic forming conditions. To evaluate the closure of porosities, hydrostatic pressure integral, which is the integral value of stress triaxiality, is commonly used. Although some experiments have been conducted on an artificial porosity of a millimeter size, there are no studies comparing experiment results and FEM analysis with the closure behaviors of a micron size porosity in a steel ingot. In this study, the shape change of center porosities during hot compression on Fe-0.25wt%C carbon steel, and stainless steel, Type316L, were sequentially, nondestructively and three-dimensionally observed by synchrotron X-ray laminography. Consequently, it was found that porosities of Type316 L were easier to be closed than those of Fe-0.25wt%C, while FEM results had the same tendency that the hydrostatic integration of Type316L had a larger value than that of Fe-0.25wt%C.This is because Type316L has a smaller work hardening coefficient in the tested temperature range than Fe-0.25wt%C.. |
| 38. | Yasutaka Mugita, Masatoshi Aramaki, Kazuhiko Yamazaki, Yoshimasa Funakawa, Osamu Furukimi, Examination of voids nucleation, growth and coalescence on ductile fracture in high tensile strength steels, EMRS (European Materials Research Society), 2017.09, Local elongation (El loc.) obtained by tensile test that relates to hole expansion ratio (?) depends on voids nucleation, growth and coalescence during tensile deformation. In this study, two kinds of 780MPa tensile strength-class steels. One was fine precipitation strengthened ferritic steel with 100% of ?, 8% of El loc. and the other was bainitic steel with 75% of ?, 5% of El loc. Voids nucleation, growth and coalescence during tensile test were examined by using Synchrotron X-ray. The test specimens were prepared by sequentially unloading of tensile force at six steps after maximum load and were observed 3-dimensionally voids by Laminography method. Number of voids nucleated in the fine precipitation strengthened ferritic steel that had higher El loc. was larger as compared to the bainite steel. The analysis results of carbon by Nano SIMS (Secondary Ion Mass Spectrometer) showed that carbon atoms segregated in grain boundaries of the bainite steel. Nano-indentation hardness increased largely on the grain boundaries of the bainite steel. From these results, it was concluded that the fine precipitates hardened ferrite steel has high El loc. and ?, because of suppressing carbon segregation which resulted in strain concentration at the grain boundaries.. |
| 39. | Effect of C grain boundary segregation on voids nucleation growth and coalescence during tensile test for high tensile strength steels. |
| 40. | Application of Shot-peening teatment for Die used for high Strength Steels. |
| 41. | Examination of Voids Nucleation and Growth Behavior for High Tensile Strength Steels in Tensile Test by Synchrotron Radiation X-Ray Laminography. |
| 42. | Analysis of closure behavior of internal void in steel during hot compressive deformation by Syncrotron Radiation X-Ray Laminography. |
| 43. | Chatcharit Kiattisaksri, Yuji Takeda, Masatoshi Aramaki, Masaki Tanaka, Osamu Furukimi, Ductile Fracture Behavior of Single Crystal Pure Iron During Tensile Test, 日本鉄鋼協会第172回秋季講演大会(2016.9), 2016.09, In most metals failure, there are two fracture modes, which are ductile and brittle fracture. This depends on the property of material to undergo large scale yielding before the fracture. At the ductile fracture during a tensile test, voids nucleate and grow after necking. Our previous study revealed that in the case of 16% Cr ferritic steel and industrial pure iron, voids nucleated mainly along Cr precipitates(1) and grain boundary(2), respectively. In this presentation, electrodeposited pure iron and whisker iron were subjected to tensile tests in order to investigate the fracture mechanics.. |
| 44. | Examination of voids nucleation and growth behavior in tensile test by Synchrotron Radiation X-Ray Laminography. |
| 45. | Yoshimine Kato, Hirotsugu Tsuchida, Kent Dobara, Masatoshi Aramaki, Osamu Furukimi, Hydrogen Trap in Seashells, PRiME 2016 (Pacific Rim Meeting on Electrochemical and Solid-state Science), 2016.10. |
| 46. | M. Yamamoto, M. Onishi, O. Furukimi, M. Aramaki, T. Yamamoto, A Method for Estimating Vickers Hardness Values Based on Nanoindentation Hardness Values, PRCM 9 (The 9th Pacific Rim International Conference on Advanced Materials and Processing), 2016.08. |
| 47. | Y. Takeda, C. Kiattisaksri, M. Aramaki, S. Munetoh, O. Furukimi, M. Yamamoto, Thickness Dependence on Void Nucleation Behavior during Tensile Test of Industrial Pure Iron and Its Effect on Deformation Energy, PRCM 9 (The 9th Pacific Rim International Conference on Advanced Materials and Processing), 2016.08. |
| 48. | Voids Nucleation Behavior of Single Crystal Iron in Tensile Deformation. |
| 49. | Chatcharit Kiattisaksri, Yuji Takeda, Masatoshi Aramaki, Masaki Tanaka, Osamu Furukimi, Voids Nucleation Behavior of Single Crystal Iron in Tensile Deformation , 日本熱処理技術協会 第81回春季講演大会、(2016)、p.1-2, 2016.05, Ductile fracture consists of voids nucleation, growth and coalescence after necking (local deformation). In this presentation, we focused on these fracture process based on the intragranular deformation, excluding grain boundary and precipitated particles. |
| 50. | Estimation of Vickers hardness by the Martens hardness instrumentation. |
| 51. | Effect of specimen thickness on deformation energy in tensile test for industrial pure iron. |
| 52. | Chatcharit Kiattisaksri, Yuji Takeda, Satoshi Oue, Masatoshi Aramaki, Osamu Furukimi, Void nucleation sites in pure iron during tensile tests, The 17th International Synmposium on Materials Science and Engineering between Chonbuk National University and Kyushu University, 2015.11, During the tensile test, after the necking takes place, voids start to be nucleated and coarsened with the increase in stress triaxility. In this report, tensile test of pure iron, containing no precipitate particles, was performed in order to investigate. |
| 53. | Yuji Takeda, Masatoshi Aramaki, Osamu Furukimi, Rintaro Ueji, Takashi Mizuguchi, Effects of strain rate and grain diameter on local deformation energy of industrial pure iron, UK-Japan Symposium on Materials Under Extreme Conditions: Effects of Temperature, High Strain Rate and Irradiation, p52, 2015.09. |
| 54. | Influence of Specimen Dimension on Stress-Strain curve. |
| 55. | Chatcharit Kiattisaksri, 竹田 祐二, Satoshi Oue, Masatoshi Aramaki, Osamu Furukimi, Void Nucleation and Growth Behavior of Pure Iron during Tensile Tests, 日本鉄鋼協会第170回秋季講演大会(2015.9), 2015.09, During the tensile test, after the necking takes place, voids start to be nucleated and coarsened with the increase in stress triaxility. In our previous study, it was found that voids nucleated mainly along precipitate particles after the necking stage of 16% Cr ferritic steel. In this report, tensile test of pure iron, containing no precipitate particles, was performed in order to investigate the voids nucleation sites.. |
| 56. | Muhammad Kozin, 吉田 幸樹, Masatoshi Aramaki, Osamu Furukimi, 山田 直矢, 山本 正之, Microstructure of Pure Iron Treated by Nitriding-Accelerated Cooling Process Followed by Aging Treatment, 日本鉄鋼協会第170回秋季講演大会(2015.9), 2015.09, Many kinds of surface hardening treatments have been developed in order to improve a wear resistance of steels. However, the processes such as carburizing and carbonitriding have a problem with dimensional changes since the process must be carried out at high temperature and long holding time. To avoid this problem, a new surface hardening process known as nitriding accelerated cooling process has been developed. In this study, microstructure of industrial pure iron treated by various conditions of nitriding treatment was examined.. |
| 57. | Improvement Anti-wear Property of Pure Iron by Nitriding-Accelerated Cooling Process Followed by Aging Treatment. |
| 58. | FEM analysis of spring back in hydrostatic bulge forming. |
| 59. | Influence of specimen thickness on deformation energy in tensile test for industrial pure iron. |
| 60. | Development of interatomic potential used for molecular dynamics calculation of Fe-N binary system material. |
| 61. | Effect on Energies for Tensile Test in duplex α-γ Stainless Steels.. |
| 62. | Effect of Material Strength on Spring Back Behavior for Bulge Forming. |
| 63. | Effect of grain diameter and strain rate on local deformation energy for pure iron (Ductile fracture mechanism of steel -5). |
| 64. | Ryosuke Ochi, Keisuke Murata, Kyono Yasuda, Masatoshi Aramaki, Masatomo Kawa, Akihiko Takahashi, Masayuki Yamamoto, Osamu Furukimi, Effect of Martensite Transformation from Austenite in Duplex Stainless Steel on Ductile Fracture Property , The 15th IUMRS-ICA (International Union of Materials Research Societies, International Conference in Asia), 2014.08, Void generation behavior and local deformation energy of two types of duplex stainless steels were studied by using uniaxial tensile tests. The chemical compositions of these samples are shown in Table1. No martensitic transformation of the austenite phase in steel A (γ:stable) can be observed, however the austenite phase in steel B (γ:unstable) transforms to the martensite by deforming.. |
| 65. | Nucleation ａｎｄ ｇｒｏｗｔｈ of porous layer in N-quench treatment.. |
| 66. | Effect of addition of shell-power lubricant on sliding behavior.. |
| 67. | Construction of 3D-image of voids in compound layer after nitriding-accelerated cooling Process. |
| 68. | Improvement of tribological effect by addition of shell powder lubricant. |
| 69. | Takuya Hirashima, Masatoshi Aramaki, Shinji Munetoh, Osamu Furukimi, Effect of Number of Grain on Ductile Fracture Behavior of Iron by Molecular Dynamics Simulation, European Conference on Heat Treatment 2014 and 21st IFHTSE Congress, p477-479, 2014.05, The ductile fracture process of iron with the various grain diameters under the tensile strain was examined at the atomic scale by means of molecular dynamics (MD) simulation. The results of the MD simulation quantitatively revealed that the energy for fracture decreased and the strain increased with the increase of the grain diameter. Additionally, the generation of dislocation was observed before the fracture in all of the crystal with the various grain diameters. Furthermore, the void was generated from the grain boundary and the fracture occurred along the grain boundary.. |
| 70. | Hiroki Katafuchi, Masatoshi Aramaki, Naoya Yamada, Nakorn Chayapiwut, Hitoshi Kabasawa, Osamu Furukimi, Improvement of Anti-wear Property by Nitriding-accelerated cooling Process, European Conference on Heat Treatment 2014 and 21st IFHTSE Congress, 511-514, 2014.05, Anti-wear property of industrial pure iron and High Strength Low Alloyed (HSLA) steel after nitriding followed by accelerated cooling was examined. The nitriding treatments were performed at 913K for 90 min. and were followed by oil-quenching. The hardness values beneath the surface in both the pure iron and HSLA steel were about 800 HV. The thickness of nitrided layer of the pure iron was smaller than that of HSLA steel. However, the wear depth per unit sliding distance in the pure iron was smaller than that in HSLA steel. It was inferred that the voids in the HSLA steel which were formed in ε phase resulted in worsening the anti-wearproperty. These findings revealed that the pure iron after nitriding and accelerated cooling has excellent anti-wear propertycomparing with the HSLA steel.. |
| 71. | Takuya Nishimura, Masatoshi Aramaki, Shinji Munetoh, Rintaro Ueji, Osamu Furukimi, Effect of tensile strain rate on ductile fracture energy for industrial pure iron, European Conference on Heat Treatment 2014 and 21st IFHTSE Congress, p467-470, 2014.05, The effect of tensile strain rate on the formation of voids by using the industrial pure iron (0.0028%C,－0.16%Mn,－0.001%Si) with few precipitates was studied. The tensile tests were performed under the initial strain rate of 10-3,101 and 103 s-1. The void distribution, the void spacing and the deformation energy in each strain rate were examined. From these experiments, it was revealed that the energy required for the coalescence of voids was increased with the increase in void spacing and the suppression of void generation by increasing the strain rate improved the local deformation energy.. |
| 72. | Strain stability of γ-phase and ductile fracture properties for duplex stainless steels. |
| 73. | FEM analysis of spring back in hydrostatic bulging for high tensile strength steel sheet. |
| 74. | Effect of grain boundary on ductile fracture property (Ductile fracture mechanism of steel -3). |
| 75. | Improvement of Tribology characteristics by Nitrogen-quenching Treatment for Steels. |
| 76. | Warm Press with the use of Shell Powder Lubricant. |
| 77. | Shinji Munetoh, Masatoshi Aramaki, Osamu Furukimi, Voids and 30,000 atoms ~Molecular dynamics (MD) simulations of the ductile fracture~, Adventures in the Physical Metallurgy of Steels (APMS), 2013.07, Molecular dynamics (MD) simulations of the ductile fracture behaviour on the austenite and ferrite phases in steel were performed by using the MD cells including the voids due to the precipitates. The number of Fe atoms were around 30,000. Atomic movements were determined by solving Langevin equations with Finnis-Sinclair interatomic force. The tensile test was simulated by expanding the MD cell in one direction at?room temperature. In the case of the perfect crystalline MD cell, the shear fracture was observed in the austenite phase, and the ferrite phase caused the cup and cone fracture. In the case of the MD cell including the voids, the cup and cone fracture?were observed on both austenite and ferrite phases. The ductile fracture energy of austenite phase was the same level to that of?ferrite phase in the perfect crystalline MD cells. However, the decrease in ductile fracture energy in austenite phase by introducing the void is higher than that in ferrite phase. These results can be applied to develop the new high ductile duplex stainless steel.. |
| 78. | Effect of N-quench Treatment on Sliding Properties in Steel Materials.. |
| 79. | Hardness and Sliding Behavior after N-quenching in pure Iron and High Tensile Steels. |
| 80. | Kosuke Abe, Hiroyuki Fukaura, Masatoshi ARAMAKI, Osamu Furukimi, FEM Analysis of Friction for Pressing Dies Controlled by Shot and Heat Treatment, European Heat Treatment Conference 2013, 2013.04. |
| 81. | Molecular Dynamics Simulation of Fracture Mechanism in Iron. |
| 82. | Effects of Interparticle spacing on ductile fracture properties. |
| 83. | Application of Shell Powder Lubricant for Warm Pressing of Mg alloy. |
| 84. | Effect of MnS amount on Local Plastic Fracture in Steels. |
| 85. | Effect of surface treatment on friction coefficient between tool and pressing material. |
| 86. | Development of lubricant containing shell powder for high-temperature press forming. |
| 87. | Effects of MnS content on ductile fracture properties evaluated by instrumented Charpy and tensile tests. |
| 88. | Surface Treatment and Sliding Property. |
| 89. | Connection Behavior of 2nd Voids on Tensile Process in a Sintered Material. |
| 90. | FEM Analysis of Improvement in Sliding Property by Surface Controlling. |
| 91. | Effect of Inclusion and Hard Phase on Ductile Fracture in Dual Phase Steels.. |
| 92. | Springback Factors of High Strength Stainless Steel.. |
| 93. | Deformation and Void Nucleation in Ferrite/Austenite Dual Phase Steel.. |
| 94. | Improvement of galling property by addition of shell powder in lubricant. |
| 95. | Hardness tests of Dual-Phase steels by nanoindentation method. |
| 96. | Influence of surface roughness before DLC deposition on sliding. |
| 97. | Difference of voids nucleation and growth processes between notchless and notched specimens in tensile test. |
| 98. | Analysis of Plastic Fracture Behavior using a EBSD for Steels. |
| 99. | Improvement of sliding Properties of Press Die with Surface Texture Control and Shell Powder Lubricant . |
| 100. | Effect of Surface Roughness before DLC Coating on Sliding Behavior. |
| 101. | Changes of Local Deformation Energy between Notchless and Notched Specimens in Tensile Test. |
| 102. | Examination of Plastic Deformation Behavior for Dual-Phase Steels by Nanoindentation Tests. |
| 103. | Study on ductile fracture behavior of Al-bearing duplex stainless steel. |
| 104. | Examination of ductile fracture mechanism for 0.2%C steels by void observation. |
| 105. | Ductile Fracture Morphology and Void Formation in Local Deformation for Ferritic Steel. |
| 106. | Difference of Voids Nucleation and Growth Process between Notchless and Notched Specimens in Tensile Test. |
| 107. | Effect of microstructure on formation ductile fracture surface in steel plate. |
| 108. | Effect of Distribution of Precipitates on Local Deformation in 16%Cr Steels. |
| 109. | Improvement of Tribological Properties of Press Die with Surface Texture Control and Shell Powder Lubricant. |
| 110. | Effect of Surface Roughness on the Friction coefficient in DLC-coated Steel Plates. |
| 111. | Effect of Surface Texture on Galling Property of Low-temperature Nitrided Die. |
| 112. | Improvement of lubricant property of cold/warm die by addition of shell powder. |
| 113. | Observation of voids nucleation and growth in steels using AsB detector. |
| 114. | Improvement of die life with surface texture control and solid lubricant. |
| 115. | Improvement of die life with surface texture control and solid lubricant. |
| 116. | Influence of microstructure on ductile fracture surface of structural plank steels. |
| 117. | Fatigue Strength in High Strength Steel Sheet with a Punched Hole. |
| 118. | Nano-indentated Hardness of Bainite Phase in 0.8%C Dual Phase Steels. |
| 119. | Influence of microstructure on ductile fracture surface of structural plank steels. |
| 120. | Fourier Analysis of Ductile Fracture Surface made by Shot Treatment. |
| 121. | Development of High Modulus Wire by using Convergence Drawing Method. |
| 122. | Lubricant Manufacture with Shell Powder for Hot Pressing. |
| 123. | The effect of Si on the precipitates for Nb bearing high-purity stainless steel. |
| 124. | Young's Modulus and Ductility Property of Fe-TiB2 Composite Wire.. |
| 125. | Development of Long-Life Die by using Low Temperature Nitriding after Shot Treatment and it's Evaluation Method. |
| 126. | Tempering Property of 0.2％C Steel in the view of Deformation Energy Theory. |
| 127. | Effect of Microstructure on Ductile Fracture Properties of Dual Phase Steels. |
| 128. | Effect of Si addition on Laves precipitation behavior in Nb doped pure ferrite steels. |
| 129. | Effect of Shared Edge on Fatigue Strength of Ultra High Strength Steel Sheets. |
| 130. | Strengthening Mechanism of Sintered Material by controlling pore morphology . |
| 131. | Effect of Graphite Diameter on Tensile Strength of Ferrous Sintered Materials. |
| 132. | The Stability of Austenite in Tensile Deformation and Its Relation to a Nitriding Treatment in Precipitation Hardened Stainless Steel. |
| 133. | The stability of austenite in tensile deformation and its relation to a nitriding treatment in precipitation hardened stainless steel. |
| 134. | The Effects of Al Content and Microstructures on the Ductile Fracture Behaviour in Duplex Stainless Steels. |
| 135. | Effects of Cr Precipitates Diameter on Local Elongation of High-Cr Steel. |
| 136. | Effect of Cu and AlN precipitates on Charpy ductile fracture propagation energy of steels. |
| 137. | Effectof Cr Precipitates Diameter on Elongatin of high Cr steel. |
| 138. | Fracture Mechanism in Cu-bearing steels obtained by 3D-image. |
| 139. | Fracture Characteristics and Improvement in Cu-containing Steels. |
| 140. | Fracture Characteristics and Improvement in precipitation hardened Fe-Cu Alloys.. |
| 141. | Development of heat resisting bearing of cobalt base alloy.. |
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