Abstract:
Mechanisms of pore formation in solid during materials processing and manufacturing are studied from experimental observations and quantitative interpretations of behavior of a bubble trapped in solid during solidification in this note. Formation of bubbles is resulted from supersaturation of the dissolved gas in the liquid ahead of the solidification front. The pores in solids are widely encountered in micro-electro-mechanical systems (MEMS), manufacturing, materials and bioscience fields. To facilitate analysis, the development of the bubble or pore in solid can be classified into five regimes: (1) nucleation on the solidification front, (2) spherical growth of the bubble, (3) solidification rate-controlled elongation, (4) disappearance of the bubble in the solid, anad (5) formation of the pores. Owing to quite different and irregular pore shapes, systematical investigations of complicated bubble dynamics in the solid during freezing are becoming important and challenging issues. Some of analyses, models and future topics are presented in this work.

Citation: P.S. Wei, "Pore formation in solid during manufacturing and materials processing," Department of Mechanical & ElectroMechanical Engineering, National Sun Yat-Sen University. MaterialsTechnology@TMS 2008.