Drag effects on grain growth dynamics

• Published in: Computational materials science Vol. 68; pp. 95 - 106
• Main Authors: Toda-Caraballo, I., Capdevila, C., Pimentel, G., De Andrés, C.G.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.2013; Elsevier
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Dispersion hardening metals; Exact sciences and technology; Grain growth; Grain size distribution; Materials science; Metals. Metallurgy; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Powder metallurgy. Composite materials; Production techniques; Solute drag pressure; Vertex simulation; Zener drag pressure; Vertex simulation; Grain growth; Solute drag pressure; Grain size distribution; Zener drag pressure; Grain size; Vertex; Statistical analysis; Oxides; Chromium alloys; Dispersion strengthened metal; Composite materials; Analytical method; Weibull distribution; Microstructure; Iron base alloys; Transition element alloys
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2012.10.012

► We analyse grain growth with drag forces by analytical and simulation point of view. ► The solution of grain growth differential equations has been solved analytically. ► A deep statistical study of grain size distributions has been carried out. ► Zener pressure has been related by a single statistical distribution parameter. ► Usual n-exponent fitting of grain growth has been related with drag forces. An analytical study of grain growth dynamics complemented with Vertex simulations is presented in this work. This has been done by including the effect of the two main drag forces in grain growth dynamics: those described by the Zener pressure (pinning particles) and Chan theory (solute drag force). The grain growth dynamics is usually addressed through fitting of the experimental measurements to a parabolic growth law, which is the solution of the mean grain size of a system free of drag forces, and the corresponding n-exponent derived. In our analysis, by contrast, analytical solutions of the grain growth dynamical equations explain and characterise the exponent variation with respect to the parameters that defines both drag forces. The Vertex simulation method completes the description of the grain size distribution, not only its mean, and allows us to characterise the evolution of the microstructure. In order to understand the results of the simulation, an analysis on the most commonly used statistical distributions describing the grain size has been carried out. It has been possible to conclude that the Weibull distribution, among all the others distributions, describes the nature of the simulated grain growth and its size distribution. As a consequence, the shape parameter k of Weibull distribution has been related with the pinning forces, being it itself a quantitative indicator of such forces. The results have been compared with experimental results with remarkable agreement, where the analytical solution and statistical relationship observed by simulation have been very useful describing and characterising the microstructure evolution.