Formation and growth mechanism of ZrC hexagonal platelets synthesized by self-propagating reaction

• Published in: Journal of crystal growth Vol. 310; no. 18; pp. 4290 - 4294
• Main Authors: Song, M.S., Huang, B., Zhang, M.X., Li, J.G.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-08-2008; Elsevier
• Subjects: A1. Crystal morphology; A1. Nucleation; A1. X-ray diffraction; B1. Zirconium carbide; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Growth from solid phases (including multiphase diffusion and recrystallization); Inorganic compounds; Materials science; Materials synthesis; materials processing; Methods of crystal growth; physics of crystal growth; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; 81.05.Je; 68.37.Hk; B1. Zirconium carbide; 81.20.Ka; A1. Nucleation; A1. X-ray diffraction; A1. Crystal morphology; 81.10.−h; Scanning electron microscopy; Crystallographic direction; Nucleation; Field emission; Self propagating high temperature synthesis; XRD; 81.10.-h; Grain coarsening; Hexagonal lattices; Lamellar structure; Blood platelets; Monolayers; Growth mechanism; Solid state crystal growth; Crystal morphology; Formation mechanism
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2008.07.016

ZrC hexagonal platelets were fabricated via self-propagating high-temperature synthesis (SHS) reaction from 20
mass% Al–Zr–C powder mixtures and a typical layered structure of the as-products was observed. The field emission scanning electron microscopy (FESEM) reveals that the thick ZrC hexagonal platelets (⩽1
μm) grew through the layer-by-layer growth mechanism of thin hexagonal monolayers along [1
1
1] direction, while the thin monolayer (⩽40
nm) was formed via two-dimensional (2D) nucleation mode along (1
1
1) plane. The formation and growth mechanism of the ZrC platelets have been discussed in detail. Al additive in the compact played an important role in determining the formation and growth of ZrC platelets, serving not only as a diluent to inhibit the ZrC grains from coarsening, but as an intermediate reactant to participate in the reaction process.