Milling Dynamics and Propagation of Mechanically Activated Self-Sustaining Reactions
- Resource Type
- Authors
- Giorgio Pia; Francesco Delogu; Alberto Cincotti; Gabriele Traversari
- Source
- Advances in Materials Science and Engineering, Vol 2020 (2020)
- Subject
- 010302 applied physics
Materials science
Article Subject
General Engineering
Equations of motion
02 engineering and technology
Mechanics
021001 nanoscience & nanotechnology
Kinetic energy
01 natural sciences
Discrete element method
Reaction rate
0103 physical sciences
Chemical conversion
TA401-492
Strong coupling
Ball (bearing)
General Materials Science
0210 nano-technology
Materials of engineering and construction. Mechanics of materials
Ball mill
- Language
- ISSN
- 1687-8442
1687-8434
This work focuses on the propagation of mechanically activated self-sustaining reactions during the mechanical processing of powder in ball mills. We use a numerical model to reconstruct the dynamics of a single ball and powder particles inside the reactor of a SPEX Mixer/Mill 8000 under operational conditions. Taking advantage of the analytical description of the reactor swing, the equations of motion of ball and powder particles are solved numerically. The discrete element method is used to describe contacts. Reaction is ignited in an individual particle randomly selected among those compressed during an impact between ball and reactor. A simple kinetic law and a set of rules involving degree of chemical conversion and distance between particles are used to obtain a phenomenological description of the reaction propagation. We show that the propagation is significantly affected by reaction rate in individual particles, with other factors being less influential. We observe a strong coupling between the dynamics of powder particles and the reaction propagation.