Solidification orientation relationships between Al3Ti and TiB2

Autor: Christopher M. Gourlay, D.J.M. King, Andrew P. Horsfield, Y. Cui
Přispěvatelé: Engineering & Physical Science Research Council (EPSRC)
Rok vydání: 2020
Předmět:
MECHANISM
Technology
PARTICLE ENGULFMENT
Materials science
Polymers and Plastics
EBSD
Materials Science
0204 Condensed Matter Physics
Nucleation
Materials Science
Multidisciplinary
GRAIN-REFINEMENT
02 engineering and technology
CRITICAL VELOCITY
Rotation
01 natural sciences
Crystallographic orientation
LATTICE-CONSTANTS
Crystal
Lattice constant
HETEROGENEOUS NUCLEATION
0103 physical sciences
Density functional theory (DFT)
Facet
0912 Materials Engineering
Materials
010302 applied physics
INOCULANT PARTICLES
Science & Technology
ALUMINUM-ALLOYS
1ST-PRINCIPLES
Intermetallic compounds (IMCs)
Metals and Alloys
Aluminium alloys
021001 nanoscience & nanotechnology
Surface energy
Electronic
Optical and Magnetic Materials
Chemical physics
Ceramics and Composites
Metallurgy & Metallurgical Engineering
Density functional theory
SOLIDIFYING INTERFACES
0210 nano-technology
0913 Mechanical Engineering
Electron backscatter diffraction
Zdroj: Acta Materialia. 186:149-161
ISSN: 1359-6454
DOI: 10.1016/j.actamat.2019.12.013
Popis: Orientation relationships (ORs) can form during solidification by a variety of mechanisms that are often difficult to distinguish after solidification. Here we study three ORs formed by the nucleation of Al3Ti on TiB2, and by the pushing and engulfment of TiB2 by growing Al3Ti facets in hyperperitectic Al-rich melts. The nucleation OR is identified by growing a relatively large TiB2 crystal, solidifying multiple small Al3Ti crystals on one (0001) facet of TiB2, and measuring the resulting OR by electron backscatter diffraction (EBSD). Pushing and engulfment ORs are investigated by statistical analysis of EBSD measurements, density functional theory (DFT) calculations of interface energies, and imaging of cross-sections of TiB2 particles being pushed and engulfed by Al3Ti facets. It is shown that the lowest energy OR is formed by nucleation as well as by pushing/engulfment. The higher energy ORs, formed by pushing and engulfment, correspond to local interfacial energy minima and can be explained by rotation of TiB2 particles on Al3Ti facets during pushing.
Databáze: OpenAIRE
Externí odkaz: