Abstract
The elongated droplets and grains can break up into smaller ones. This process is driven by the interfacial free energy minimization, which gives rise to a breakup limit. We demonstrated in this work that the breakup limit can be overpassed drastically by using electric current to interfere. Electric current free energy is dependent on the microstructure configuration. The breakup causes the electric current free energy to reduce in some cases. This compensates the increment of interfacial free energy during breaking up and enables the processing to achieve finer microstructure. With engineering practical electric current parameters, our calculation revealed a significant increment of the obtainable number of particles, showing electric current a powerful microstructure refinement technology. The calculation is validated by our experiments on the breakup of Fe3C-plates in Fe matrix. Furthermore, there is a parameter range that electric current can drive spherical particles to split into smaller ones.
Highlights
Fabrication of nanoscale grains[1], droplets[2,3] and bubbles[4] has attracted significant attentions in recent decades
Electric current free energy is different from the chemical free energy in a way being dependent on the microstructure configuration
The breakup causes the change of electric current free energy
Summary
Fabrication of nanoscale grains[1], droplets[2,3] and bubbles[4] has attracted significant attentions in recent decades. Microstructural elements (grains, droplets, bubbles, etc.) are stretched into long thin plates by severe mechanical deformation followed by breakup into smaller pieces and subsequent spheroidization. E.g. surfactant and micelle[10], have negative interfacial tension (σ < 0) In those materials a spherical droplet may turn itself into cylindrical or split into smaller ones in order to increase the total interfacial area and to reduce the total system interfacial energy. The stretched thin plates or thin films are able to break up into more number of finer pieces with each piece has smaller diameter after spheroidization. This pushes the refinement processing toward the fabrication of much finer microstructure. The results are generic for the breakup of any grains, droplets and bubbles submerged in a higher conductive matrix
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
