著者

高橋 恒夫 神尾 彰彦 チェン グエンアン

出版者

一般社団法人 軽金属学会

雑誌

軽金属 (ISSN:04515994)

巻号頁・発行日

vol.25, no.4, pp.134-140, 1975-04-30 (Released:2008-07-23)

参考文献数

12

被引用文献数

2 2

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The morphological transition from planar to cellular interface in Al-Ti alloys occurs at a constant value of C0•R/G and the cell-dendrite transition occurs at a constant value of C0•R1/2/G, where C0 is the initial solute concentration, R growth rate and G temperature gradient. As the planar interface breaks down to form depressions, a rod-like cored substructure is formed in each cell when the interfacial morphology changes successively from depressions to irregular cells, elongated cells and hexagonal cells. The rod-like substructure is transformed into the dendrite as the cellular interface changes into dendritic. The length of rods and dendrites becomes shorter with an increase in C0•R/G. The cored region is enriched with Ti, and its content is about 2.5-4.0 times of the initial solute concentration. The matrix of cellular and dendritu interface is extremely depleted in the solute, and its concentration is about 1/3-1/5 of C0.The diffusion coefficient for the solute Ti in the liquid Al at the liquidus temperature is calculated to be 0.87×10-5cm2/sec.