[8/3] The 44th “AIMR Tea Time Talk”
Speaker
Prof. Hyoung Seop Kim
(Pohang University of Science and Technology (POSTECH), Korea / PI of AIMR)
Title
Additive Manufacturing of High Entropy Alloys
Date
August 3 (Thu.), 2023 16:00–17:00 on Japan Time
Venue
Combination Room on the 5th floor, AIMR main building
Abstract
Metal additive manufacturing (MAM) offers unprecedented advantages in the fabrication of metals and alloys with complex geometry and unique microstructural features with hierarchical heterogeneity. The MAM process also induces a unique cell structure with high dislocation density and solute segregation at cell boundaries. Here, we propose an innovative utilization of a unique dislocation network to achieve superior mechanical properties through metastability engineering of high entropy alloy (HEA) and ferrous-medium entropy alloy (FeMEA). While the high dislocation density at cell boundaries contributes to the improvement of yield strength as additional barriers to dislocation movement, the solute segregation at cell boundaries can beneficially control the phase instability of the matrix in materials produced by MAM. Our results demonstrate that solute segregation at cell boundaries decreases the face-centered cubic phase stability in the matrix and activates the transition of the deformation mechanism from slip to metastable plasticity (i.e., transformation-induced plasticity). Furthermore, the high density of dislocation at cell boundaries also has an effect on not only yield strength enhancement but also on controlling kinetics of metastable plasticity, and it beneficially contributes to obtaining high ductility of the MAM-processed FeMEA. This work presents a new microstructural design strategy for beneficially customizing the material performance of high-quality products based on MAM-driven metastability engineering of an alloy with specific chemical composition.
About Tea Time Talk
AIMR’s Tea Time Talk is a kind of seminar aiming to promote exchange between world’s eminent researchers and young researchers at AIMR, held in a relaxed atmosphere at AIMR’s Friday Tea Time. The following researchers from around the world have given talks at this event so far, and participants have enjoyed discussion over a cup of tea.
| 43rd | July 21, 2023 | Prof. Feral Temelli (University of Alberta, Canada) |
|---|---|---|
| 42nd | June 30, 2023 | Dr. Douglas Brumley (The University of Melbourne, Australia) |
| 41st | Mar. 28, 2023 | Prof. Motomu Tanaka (Physical Chemistry of Biosystems, Institute of Physical Chemistry, Heidelberg University, Germany) |
| 40th | Nov. 10, 2022 | Prof. Masahiro Yoshimura (National Cheng Kung University, Taiwan) |
| 39th | June 17, 2022 | Prof. Rana Mohtadi (Toyota Research Institute of North America) |
| 38th | June 17, 2022 | Prof. Michael Hirscher (Max-Planck-Institute for Intelligent Systems, Germany) |
| 37th | June 3, 2022 | Prof. Reiko Oda (French National Centre for Scientific Research) |
| 36th | May 28, 2021 | Prof. Magda Titirici (Imperial College London, U.K.) |
| 35th | Mar. 26, 2021 | Prof. Yaroslav Blanter (Kavli Institute of Nanoscience, Delft University of Technology) |
| 34th | Oct. 23, 2020 | Dr. Kazuhito Tsukagoshi (PI:WPI-MANA, NIMS & AIMR) |
| 33rd | July 17, 2020 | Prof. Kaoru Tamada (IMCE, Kyushu University & AIMR) |
| 32nd | Jan. 17, 2020 | Prof. Miho Yamauchi (I2CNER / Kyushu University & AIMR) |
| 31st | Jan. 17, 2020 | Prof. Mickaël Lallart (INSA Lyon, Université de Lyon) |
| 30th | Oct. 25, 2019 | Assoc. Prof. Frédéric Gillot (Department of Solid Mechanics, Mechanical Eng. and Civil Eng., École Centrale de Lyon) |
| 29th | July 12, 2019 | Prof. Qian Niu (Department of Physics, The University of Texas at Austin) |
| 28th | May 17, 2019 | Prof. Damien Fabrègue (INSA Lyon, France / ELyT MaX Lab at Tohoku University) |
| 27th | Dec. 14, 2018 | Prof. Yukitoshi Motome (Department of Applied Physics, The University of Tokyo, Japan) |
| 26th | July 13, 2018 | Dr. Shimpei Ono (Central Research Institute of Electric Power Industry, Japan) |
| 25th | May 11, 2018 | Dr. Pierre-Antoine Geslin (Mateis lab, INSA Lyon/CNRS / ELyTMaX Lab at Tohoku University / Institute for Materials Research, Tohoku University) |
| 24th | Apr. 27, 2018 | Prof. Masaru Tsukada (AIMR, Tohoku University) |
| 23rd | Dec. 8, 2017 | Prof. Jean-Yves Cavaillé (INSA Lyon, France / ELyT MaX Lab at Tohoku University) |
| 22nd | July 28, 2017 | Prof. Nicolas Mary (INSA Lyon, France / ELyT MaX Lab at Tohoku University) |
| 21st | July 21, 2017 | Prof. Gael Sebald (INSA Lyon, France / ELyT MaX at Tohoku University) |
| 20th | July 7, 2017 | Prof. Arun Bansil (Northeastern University) |
| 19th | June 30, 2017 | Dr. Takeshi Nakanishi (AIST-Tohoku U Mathematics for Advanced Materials Open Innovation Laboratory (MathAM-OIL)) |
| 18th | June 23, 2017 | Prof. Denis Arčon (Jožef Stefan Institute, Slovenia) |
| 17th | Apr. 28, 2017 | Prof. Ayumi Hirano (AIMR, Tohoku University) |
| 16th | Nov. 29, 2016 | Dr. David Guy Austing (National Research Council Canada, Canada) |
| 15th | Sept. 30, 2016 | Prof. C. Suryanarayana (University of Central Florida, U.S.A.) |
| 14th | June 17, 2016 | Prof. Tomoteru Fukumura (AIMR, Tohoku University) |
| 13th | May 13, 2016 | Prof. Jean-Yves Cavaillé (ELyT MaX (Joint Lab at Tohoku University), University of Lyon, France) |
| 12th | June 26, 2015 | Dr. B. Muralidharan (Indian Institute of Technology Bombay, India) |
| 11th | June 27, 2014 | Prof. Michael B. Santos (The University of Oklahoma, U.S.A.) |
| 10th | Nov. 19, 2013 | Dr. Pawel Hawrylak (National Research Council Canada, Canada) |
| 9th | Oct. 1, 2013 | Dr. Yuan T. Lee (Nobel laureate in Chemistry, Academia Sinica of Taiwan) |
| 8th | June 28, 2013 | Dr. Bjorn Mysen (Geophysical Laboratory, Carnegie Institution for Science, U.S.A.) |
| 7th | Apr. 12, 2013 | Prof. Yiming Li (National Chiao Tung University, Taiwan) |
| 6th | Jan. 18, 2013 | Prof. Tomasz Dietl (Polish Academy of Sciences, Poland) |
| 5th | Aug. 31, 2012 | Prof. John H. Perepezko (University of Wisconsin-Madison, U.S.A.) |
| 4th | Aug. 17,2012 | Prof. Alain Reza Yavari (Grenoble Institute of Technology, France) |
| 3rd | Aug. 10, 2012 | Prof. Alan Lindsay Greer (University of Cambridge, U.K.) |
| 2nd | July 6, 2012 | Prof. Winfried Teizer (Texas A&M University, U.S.A.) |
| 1st | May 25, 2012 | Prof. Thomas P. Russell (The University of Massachusetts Amherst, U.S.A.) |
Contact
International Affairs Center (IAC)
| Address : | 2-1-1, Katahira, Aoba-ku, Sendai, 980-8577 |
|---|---|
| Tel : | +81-22-217-5971 |
| E-mail : | iac@grp.tohoku.ac.jp |