Year: 1977
Type: article
Abstract: Electron microscopy shows that some of the alloys have a dendritic cored structure and a metastable phase TiAl3 (Ll2 type ordered structure) with a prefered growth direction <100>. Tangled dislocations are concentrated around the cored structures. The decomposition of the metastable phases during annealing at 400 to 500°C proceeds subdividing and coarsening themselves. After the completion of this process spherically grown particles begin to transform into the equilibrium phase TiAl3 having tetragonal structure. The orientation relationships between the equilibrium phase and the matrix are [001]TiAl3//[001]Al, (010)TiAl3//(110)Al. Precipitation in the supersaturated solid solution of Al-Ti alloys anneaed at 400 to 500°C can be metallographically classified: i) precipitation within matrix grains accompanying coherent strain, ii) prefered precipitation on the dislocations, and iii) precipitation caused by a grain boundary reaction.
DOI: 10.2464/jilm.27.105
Authors: Teruo OHASHI, Riei ICHIKAWA
Institution: Nagoya Institute of Technology
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4253027331