A multilayer model for self-propagating high-temperature synthesis of intermetallic compounds

Area of Science:

• Materials Science
• Chemical Engineering
• Physical Chemistry

Background:

• Self-propagating high-temperature synthesis (SHS) is crucial for intermetallic compound production.
• Understanding reactions in binary systems with selective melting is key for controlling SHS processes.
• Existing models often lack detailed kinetic descriptions for systems with distinct melting behaviors.

Purpose of the Study:

• To develop a general theory for SHS in binary systems where one component melts.
• To derive kinetic equations describing phase interface propagation and melt composition changes.
• To validate the theory using a numerical solution for the Al-Ni system.

Main Methods:

• Development of a theoretical model for reactions in a solid particle within a molten metal bath.
• Utilizing binary system phase diagrams to define reaction pathways.
• Derivation of kinetic equations for one- and two-layer binary compound systems.
• Numerical solution of the derived equations for the Aluminum-Nickel (Al-Ni) system.

Main Results:

• A general theory for SHS in systems with selective melting was established.
• Kinetic equations were derived to describe interface propagation and melt composition dynamics.
• Numerical simulations for Al-Ni demonstrated the theory's practical applicability.
• The model is adaptable to systems with more complex phase diagrams and multiple layers.

Conclusions:

• The presented theory provides a robust framework for understanding SHS in specific binary systems.
• The derived kinetic equations offer predictive capabilities for reaction progression and product formation.
• The methodology is generalizable, offering potential applications for a wider range of intermetallic compound synthesis.