Macrokinetics of Mechanosynthesis in Solid-Gas Systems. II. Experimental Studies. Analysis of Results

Abstract

Results from experimental studies of the nonisothermal mechanochemical reaction in the titanium-nitrogen system. Experimental data are compared with simulation results. The effective kinetic parameters of mechanical activation of the reactant and the chemical reaction are determined from analytical relations. It is shown that the developed mathematical model is suitable for the analysis of the macrokinetics of nonisothermal chemical reactions in solid reactant-reactive gas systems.

Role of Mixing and Milling in Mechanochemical Synthesis (Review)

“…The macroscopic theory was used to design, numerically and analytically study mathematical models of mechanochemical synthesis for the system comprised of a solid reactant and a reactive gas and for a heterogeneous system of solid reactants in the wave and volumetric (thermal explosion) modes of the chemical reaction [264][265][266] (Fig. 6).…”

Discrete One-Stage Mechanochemical Synthesis of Titanium-Nitride in a High-Energy Mill

“…To solve this problem, the following initial data were used [29,37]: c Ti = 528 J/(kgK), c s = c m = 462 J/(kgK), ρ Ti = 4500 kg/m 3 , ρ s = ρ m = 7900 kg/m 3 , Q = 5.8 × 10 5 , E = 141,510 J/mol, k 0 = 2.8 × 10 4 s −1 , M g = 28 × 10 −3 kg/mol, µ = 0.23, b = −0.17, ω/∑(v i c i ρ i ) = 70 K/min, V = 6 × 10 −2 m 3 , S = 0.72 m 2 . It was assumed that for the running mill the coefficient χ = 10 J/(s K m 2 ), and for the stop of the mill under forced cooling conditions χ = 1000 J/(s K m 2 ).…”

“…Temperature factor, caused by heating of milling bodies, chamber walls, and a grinding substance (dissipative heat release), as well as by heat release from the relaxation of structural defects and chemical reactions. In [28,29], the authors determined the efficient kinetic parameters using experimental and theoretical methods and analyzed the nonisothermal chemical transformations of twostage mechanochemical synthesis of titanium nitride. The developed mathematical model was found to be suitable for the analysis of the macrokinetics of chemical transformations in the solid reagent-active gas systems.…”

Effect of phase transformation on nonisothermal synthesis in mechanically activated heterogeneous systems

“…The changes in the excess energies of the reagents and the product are determined by the equations [1][2][3][4][5] …”

“…The macrokinetics of such processes was considered in [3][4][5]. In the course of heating and chemical conversion of the reacting mixture, excess energy relaxation is assumed to follow two paths [6]: "normalization" of the structure and chemical reaction.…”