Page 1 of 1
shield time and shield distance
Posted: Sun Jul 24, 2022 4:21 pm
by Jane
Hi，everyone，
Can you explain the physical meaning of shielding time and shielding distance?
Thank you.
Re: shield time and shield distance
Posted: Mon Jul 25, 2022 3:21 pm
by Bernd
Dear Jane,
When nucleation happens, the latent heat of phase transformation will locally heat up the material, so that for a certain time there will be no further nucleation happen up to a certain distance around this seed.
The use of a shield distance and shield time in the nucleation input is a pragmatic approach which resembles this behavior in simulations which do not explicitly include latent heat release and heat diffusion. Practically, it allows for adjusting nucleation parameter such as to realize a given density of precipitates (which may be known from experiments).
Bernd