The average data of the primary, secondary and tertiary dendrite arm spacing as a function of the y From Lo
interface velocity are shown in Fig. 9.
+, Scmub
Keramik
350 +
_ 310.04
5 300 | a —— Primary spacing reine
a 250 ym -&- Secondary spacing er
5 | Ea -o- Tertiary spacing ders z
b) 200 -} — are den
| 450° oo
£ 100 A die
S 103.8 4! and the ins
A NT gg AI nn
0 2763 pe
0.E+00 2.E-04 4E04 6E-04 8E-04 1E-03 wr
Solid/liquid interface velocity, m/s Brn
eri I
Fig. 9: Effect of the interface velocity on the dendrite arm spacings Cone
have very
Conclusions MD = ; )
Steady-state unidirectional solidification experiments were performed using Al-4wt%Cu samples ni
and the developed solidified dendritic microstructure was studied. Hae |
An exact measuring method was worked out for determining the dendritic structure parameters such pe :
as primary, secondary and tertiary dendrite arm spacing, and for measurement of amount of the ~~ =
second phase, too. The ceran
As a result of the examinations it was stated, that: bere:
— Increasing the interface velocity the amount of the second phase was increased, Wr
— Increasing the interface velocity the values of primary, secondary and tertiary dendrite arm N es
spacing were decreased. The dendrite morphology became continually finer. =
i
Anew fi
References medical 1
the mater
(1) H. Jacobi, K. Schwerdtfeger: “Dendrite morphology of steady state unidirectionally solidified “le
steel”, Met. Trans. 7A (1976), 811. Microstru
(2) J. A. Horvath, L. F. Mondolfo: “Dendritic growth”, Acta Met. 10, (1962), 1037. ie
(3) Z. Gacsi, A. Roodsz: “Stereometric characterization of unidirectionally solidified dendritic "=x
structure”, Acta Stereol. 13, no. 2, (1994), 335. os
(4) K.P. Young and D. H. Kirkwood: “The Dendrite Arm Spacings of Aluminum-Copper Alloys ~~
Solidified Under Steady-State Conditions”, Met. Trans. 6A, (1975), 197. The deve
(5) Zs. Csepeli, Z. Gäcsi: “Microstructure of unidirectionally solidified fiber reinforced AO
composites”, Acta Stereol. 18, no. 3., (1999), 341. % In or
+ 1.0
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