Directional Solidification Microstructure Evolvement of Al-4.5Cu Alloy under Different Pulling Velocity Conditions

2012 ◽  
pp. 709-716
Author(s):  
Chunhua Tang ◽  
Cui Liang ◽  
Jinjun Tang ◽  
Meng Xu ◽  
Guangming Zhang
Keyword(s):  
Directional Solidification ◽  
Solidification Microstructure ◽  
Pulling Velocity

Simulation of Bridgman Directional Solidification Microstructure Using Phase Field Method

2013 ◽  
Vol 652-654 ◽  
pp. 2437-2440
Author(s):  
Chunhua Tang ◽  
Jin Jun Tang ◽  
Cui Liang
Keyword(s):  
Grain Boundary ◽  
Directional Solidification ◽  
Phase Field ◽  
Field Method ◽  
Planar Interface ◽  
Solidification Microstructure ◽  
Phase Field Method ◽  
Initial Stage ◽  
Last Stage ◽  
Pulling Velocity

In this paper, the directional solidification microstructure of Bridgman system was simulated using phase-field method, and different calculated results were obtained with four pulling velocities. When the pulling velocity is 0.06 cm/s, the columnar crystals competitively grow in the initial stage, and have a necking phenomenon in the last stage. When the pulling velocity is 0.04 cm/s, the columnar crystals become thinner and competitively grow all the time, and the microsegregation is bigger. When the pulling velocity is 1.00 cm/s, planar interface comes back, and solute trapping takes place. The columnar crystals become much thinner, and microsegregation decreases. When the pulling velocity is 3.00 cm/s, the grain boundary of columnar crystals becomes unconspicuous, and the degree of microsegregation approaches 1.

Formation of Ferrite with Cr Equivalents and Solidification Rates in Mod. (9-12)Cr-1Mo Steels

2007 ◽  
Vol 124-126 ◽  
pp. 1497-1500
Author(s):  
Y.H. Kim ◽  
H.C. Kim ◽  
Yeon Gil Jung ◽  
J.H. Lee ◽  
B.H. Chi ◽  
...  
Keyword(s):  
Directional Solidification ◽  
Volume Fraction ◽  
Solidification Rate ◽  
Liquid Interface ◽  
Solidification Microstructure ◽  
Composition Change ◽  
Heat Treated ◽  
Solid Liquid Interface ◽  
Solid Liquid

The influence of solidification rates and Cr equivalents on the formation of the ferrite was studied by directional solidification in mod. (9-12)Cr-1Mo steels. It was found that the volume fraction of ferrite increased as increasing Cr equivalent and solidification rate. The volume fraction of the ferrite showed much higher at low solidification rates with the planar or cellular interface than that at high solidification rates with the dendritic interface. The volume fraction of ferrite in solidification microstructure showed much higher than that in extruded and heat-treated alloys. It depends on not only solidification rate and Cr equivalent but also the solidification fraction. At low solidification rates, there occurs segregation because the solid/liquid interface was planar or cellular, and it makes composition change with solidification fractions. The formation of ferrite has been discussed with Cr equivalent and solidification rate.

Tilted Dendritic Growth Dynamics and Dendrite to Degenerate Seaweed Transition in Directional Solidification: Insights from Phase-Field Simulations

2018 ◽  
Vol 15 ◽  
pp. 128-153
Author(s):  
Hui Xing ◽  
Xiang Lei Dong ◽  
Jian Yuan Wang ◽  
Ke Xin Jin
Keyword(s):  
Directional Solidification ◽  
Misorientation Angle ◽  
Phase Field ◽  
Dendritic Growth ◽  
Growth Dynamics ◽  
Growth Direction ◽  
Primary Spacing ◽  
Stability Range ◽  
Spacing Selection ◽  
Pulling Velocity

In this paper, we review our results from phase field simulations of tilted dendritic growth dynamics and dendrite to seaweed transition in directional solidification of a dilute alloy. We focus on growth direction selection, stability range and primary spacing selection, and degenerate seaweed-to-tilted dendrite transition in directional solidification of non-axially orientated crystals. For growth direction selection, the DGP law (Phys. Rev. E, 78 (2008) 011605) was modified through take the anisotropic strength and pulling velocity into account. We confirm that the DGP law is only validated in lower pulling velocity. For the stability range and primary spacing selection, we found that the lower limit of primary spacing is irrelative to the misorientation angle but the upper limit is nonlinear with respect to the misorientation angle. Moreover, predicted results confirm that the power law relationship with the orientation correction by Gandin et al. (Metall. Mater. Trans. A. 27A (1996) 2727-2739) should be a universal scaling law for primary spacing selection. For the seaweed-to-dendrite transition, we found that the tip-splitting instability in degenerate seaweed growth dynamics is related to the M-S instability dynamics, and this transition originates from the compromise in competition between two dominant mechanisms, i.e., the macroscopic thermal field and the microscopic interfacial energy anisotropy.

Directional solidification, microstructure and properties of the – eutectic

2005 ◽  
Vol 275 (1-2) ◽  
pp. e153-e158 ◽  
Author(s):  
C.T. Rios ◽  
S. Milenkovic ◽  
P.L. Ferrandini ◽  
R. Caram
Keyword(s):  
Directional Solidification ◽  
Solidification Microstructure ◽  
Microstructure And Properties
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