Researcher of the Year 2018 - Professor T. Venkatesan. The advanced materials community would like to take this opportunity to pay rich tributes to Professor T. Venkatesan for his pioneering research and notable contributions to nanoscience and nanotechnology. Advanced Materials Letters have been selected his photo for the cover of this special year-end issue.
Effect of Al on the columnar-to-equiaxed transition for Ti-6%Al and Ti-45%Al by cellular automaton
Min Zhang*, Yulan Zhou, Qin Xue, Jihong Li, Erlong, Mu
Department of Material Shaping and Control, School of Materials Science and Engineering, Xi’an University of Technology, NO.5 South Jinhua Road, Xi’an 710048, China
Adv. Mater. Lett., 2018, 9 (12), pp 889-894
Publication Date (Web): Sep 14, 2018
Copyright © 2018 VBRI Press
A dendritic growth model is established by combining the physical properties of dendritic growth with the characteristics of the cellular automaton (CA) method. The heat process and the molten pool model of the arc-shaped in the process of welding solidification are coupled by using the interpolation method. On the basis of that, the growth of dendrites in the molten pool for Ti-6%Al and Ti-45%Al alloys is simulated and the influence of aluminium content on the morphology of dendrites in the welding solidification process is analysed. And also the microstructural evolution of the molten pool during the solidification process is implemented under the condition of the non-uniform temperature field. The results indicate that the temperature presents the gradual distribution in the non-uniform temperature field and the microstructure grows competitively at the center of the molten pool. During the progress of solidification, the solute atoms are enriched in between dendrite arms with the segregation of solute. Simultaneously, with the change of temperature field, the morphology of dendrites has asymmetry. In addition, the columnar crystals are largely converted to equiaxed crystals for Ti-6%Al alloy while the result is the opposite for Ti-45%Al alloy resulting from the change of the aluminium content. The simulated results are in good agreement with the experimental ones.
Cellular automaton, dendritic distribution, solute concentration, welding heat process.