Ceramic powder is pressed into a shape and sintered to get a polycrystalline dense solid. By continued heating the grains grow larger, in order to decrease grain boundary energy, which is a natural process. By continued heating, can we change the poly crystalline shape into a single crystal? I am looking for an alternative method to single crystal growth from melts.
From the thermodynamic point of view, yes, perfect single crystal can be obtained by "continued" annealing of the poly crystalline material because the perfect single crystal is the most stable state for the material. However, it is very difficult to achieve that "practically" when there is an equilibrium, at the grain-boundary junctions of the meta-stable poly crystalline state, between the forces that each boundary exerts on the grain-boundary junction. For this reason, very high activation energy and very long annealing time are required for such change in the materials. Hence, this route is NOT recommended practically.
Dear Balakrishna
The answer is no, because of thermoganamic reasons.
The common way of obtaining a single crystal of a metal
is by growing the single crystal of a molten metal at a solid
substrate with a certain crystallographic plane, i.e., (111) &
a certain crystallographic direction[110].
Refer to the video link for more details:(https://www.youtube.com/watch?v=Rl-yPvn7NPo)
Balakrishna... Single crystal preparation is an art and a result of very careful non-disturbed environment. Heating may remove some strains from a material but never activate growing of a single crystal. So read more and start the preparation from the begining; with slow (natural) evaporation of solvent under non-disturbed environment. Good luck
A possible route is abnormal grain growth (AGG).
See references: https://www.nature.com/articles/s41467-017-00383-0 https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1151-2916.2002.tb00257.x
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