Regression based computer vision analysis of volume-fraction effect on Pb–Sn solid–liquid coarsening in microgravity

Outcomes of coarsening experiments performed in solid–liquid mixture of various Pb–Sn systems, under microgravity, are investigated to explicate the influence of volume fraction on coarsening kinetics. A computer vision technique capable of efficiently ascertaining the number of Sn-rich solid precipitate is developed. After sufficient training and validation, this object detection model is employed to micrographs of Pb–Sn systems captured at different stages of coarsening. The change in the number density of the precipitate with time is monitored for different Pb–Sn systems of varying phase fractions, ranging from 5 to 80% precipitates, and the corresponding kinetics coefficient is determined using regression. Examining the kinetic coefficients in relation to phase fractions unravels that the volume of Sn-rich solid has negligible effect on the steady-state coarsening rate of the Pb–Sn solid–liquid mixture under microgravity. The indefinite and marginal effect of precipitate volume-fraction on kinetic coefficient apparently substantiates the trans-interface diffusion governed coarsening in Pb–Sn system, as opposed to generally held dominance of matrix diffusion.