|Table of Contents|

 Simulation of Grain Structure Formation of Ti-46at. %Al Alloy
During Directional Solidification with CAFE Model
(PDF)

《哈尔滨理工大学学报》[ISSN:1007-2683/CN:23-1404/N]

Issue:
2017年06期
Page:
102-108
Research Field:
材料科学与工程
Publishing date:

Info

Title:
 Simulation of Grain Structure Formation of Ti-46at. %Al Alloy
During Directional Solidification with CAFE Model
Author(s):
 LIU Dong-rongLU Hai-yangGUO Er-jun
School of Material Science and Engineering,Harbin University of Science and Technology,Harbin 150080,China)
Keywords:
 TiAl alloy cellular automation-finite element simulation grain structure segregation
natural convection
PACS:
TG244
DOI:
10. 15938 /j. jhust. 2017. 06. 019
Abstract:
 In order to deeply understand the mechanisms responsible for the grain structure evolution during
directional solidification of Ti-46at. % alloy,characteristics of grain structure were simulated using CAFE model
( Cellular Automaton-Finite Element) . CAFE model was validated by comparisons with microgravity experiments
from a reference. Influences of nucleation undercooling and natural convection intensity on columnar-to-equiaxed
transition ( CET) ,grain size,grain elongation and segregation were numerically investigated. Simulated results
show that a fully equiaxed grain structure is obtained by lowering the nucleation undercooling. Increasing flow
intensity aggravates intergranular segregation,but barely has effects on variations of grain structure morphology and
distributions of grain size and elongation. With a high nucleation undercooling,CET occurs. By strengthening fluid
flow,the occurrence of CET is retarded,a mixed structure of elongated and equiaxed grains is formed,both grain
sizes and elongations are increased and segregation is enhanced. CAFE model can be used to predict grain structure
evolution during solidification of Ti-46at. %Al and to analyze the controlling mechanisms.

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Last Update: 2018-03-10