Driving Force
The boundary between one grain and its neighbour is a defect in the crystal structure and so it is associated with a certain amount of energy. As a result there is a thermodynamic driving force for the total area of boundary to be reduced. If the grain size increases, accompanied by a reduction in the actual number of grains, then the total area of boundary will be reduced.
In comparison to phase transformations the energy available to drive grain growth is very low and so it tends to occur at much slower rates and is easily slowed by particles or solute atoms.
Read more about this topic: Grain Growth
Famous quotes containing the words driving and/or force:
“I try to make a rough music, a dance of the mind, a calculus of the emotions, a driving beat of praise out of the pain and mystery that surround me and become me. My poems are meant to make your mind get up and shout.”
—Judith Johnson Sherwin (b. 1936)
“The difference between a photograph and even the most realistic painting—say, one of Courbet’s landscapes—is that in the latter there has been selection, emphasis and some discreet distortion. The painter’s deep instinctive feeling for mass and force has rearranged everything.”
—Gerald Branan (1894–1987)