Phase-field Simulation Of Forced Flow Effect On Solidification Microstructure

Undercooled melt forced laminar flow effect on heat transmission, mass transmission and momentum transmission during solidification. A new model (Sola-Phase Field Model, S-PFM) was built, which was combined the phase field model of diffusion and the algorithm sola method, to exhibit solidification microstructure evolvement process and to study theory of forced laminar flow effect on dendritic solidification. The sola algorithm is erected by self-adaptive pressure iteration method.Take high pure succinonitrile (SCN) as example, single grain morphology and thermal field under melt forced laminar flow in non-isothermal condition was studied. Latent heat of crystallization and thermal disturber were conceded. Results show that equiaxed of grain's morphology is brokered for laminar flow. Forced flow rate effect on upstream tip, downstream tip and tip normal to flow growth velocity were anglicized, results show that tip growth velocity and tip radius of upstream dendrite increase compeered with without flow,. What's more, the higher melt inflow rate, the higher growth velocity of upstream tip, and the higher solidification ratio of single grain. Growth velocity of downstream tip is not stable, swirl will emerged when melt inflow rate enough higher or size of dendrite enough bigger.In addition, based on S-PFM, the random grid method which was designed by author was used to simulate forced laminar flow effect on multiple grains growth process. Simulation results shows that the S-PFM combined with the random grid method can describe forced laminar flow effect on multiple grains growth process effectively. Compeered dendrite morphology when melt without flow with it when melt with flow, secondary and higher dendritic arm have a "one-sided" tendency that toward upstream. What's more, solidification ratio is proportional to melt inflow velocity when solidification ratio is lower; however, solidification ratio of melt with flow is equal to solidification ratio of melt without flow when solidification ratio is higher.In the last, results of author were compeered with conclusion of foreign researchers. Results show that simulation results of the S-PFM are agree well with foreign researchers's. The S-PFM can simulate forced laminar flow effect on microstructure of solidification.The study is help to understand solidification process more profoundly in theory; in engineering, it is theory base in developing macro-micro coupled simulation software. So, the study has potential practical value, too.