| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Defect and Phase Transformation Pathway Engineering for Desired Microstructures
|
| Presentation Title |
Anisotropic Thermal Lattice Expansion and Crystallographic Structure of Strontium Aluminide within Al-10Sr Alloy as Measured by In-situ Neutron Diffraction |
| Author(s) |
Klaus-Dieter Liss, Stefanus Harjo, Takuro Kawasaki, Kazuya Aizawa, Pingguang Xu |
| On-Site Speaker (Planned) |
Klaus-Dieter Liss |
| Abstract Scope |
Knowledge of thermal evolution of precipitate is essential for microstructural design. The aluminium strontium master alloy Al-10Sr has been investigated by in-situ neutron diffraction upon a heating-cooling cycle, revealing composition, crystallographic structure, lattice evolution and linear thermal expansion coefficients. Expansion of the Al matrix between [23.5 … 26.7]·10‑6 K‑1 fits well to the literature values, extrapolating to higher temperature at 800 K. Thermal expansion is highly anisotropic for tetragonal Al4 Sr by a factor of 1.86 with values of 20.8 and 11.1·10‑6 K‑1 in a and c-axis. The discrepancy to the matrix explains residual intergranular phase stresses and brittleness of such composite material. Upon first heating, recovery is observed until 600 K and 700 K, for Al4 Sr and Al. Rietveld analysis refines the Wyckoff positions of the I 4/m m m crystal structure. Its lattice parameters report to aI = 4.44240(48) Å, cI = 11.0836(15) Å at 300 K. |
| Proceedings Inclusion? |
Planned: |