Effect of growth rates and temperature gradients on the spacing and undercooling in the broken-lamellar eutectic growth (Sn-Zn eutectic system)
Küçük Resim Yok
Tarih
2003
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
ASM INTERNATIONAL
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
The Sn-Zn system has a eutectic structure of a broken lamellar type. Dependence of the broken-lamellar spacing lambda and the undercooling DeltaT on V and G were investigated, and the relationship between them was examined. A Sn-Zn (99.99%) high-purity eutectic alloy was melted in a graphite crucible under vacuum atmosphere. This eutectic alloy was directionally solidified upward with a constant growth rate V (8.30 mum/s) and different temperature gradients G (1.86-6.52 K/mm), and also with a constant temperature gradient (6.52 K/mm) and different growth rates (8.30-165.13 mum/s) in a Bridgman-type directional solidification furnace. The lamellar spacings lambda were measured from both transverse and longitudinal sections of the specimen. The lambda values from the transverse section were used for calculations and comparisons with the previous works. The undercooling values DeltaT were obtained using growth rate and system parameters K-1 and K-2. It was found that the values of lambda decreased while V and G increased. The relationships between lamellar spacing lambda and solidification parameters V and G were obtained by linear regression analysis method. The lambda(2)V, DeltaTlambda, DeltaTV(-0.5), and lambda(3)G values were determined using lambda, DeltaT, V, and G values. The experimentally obtained values for the broken-lamellar growth (Sn-Zn eutectic system) were in good agreement with the theoretical and other experimental values.
Açıklama
Anahtar Kelimeler
broken-lamellar growth, directional solidification, eutectic alloys, lamellar spacings, Sn-Zn eutectic alloys, undercooling, microstructure
Kaynak
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
WoS Q Değeri
Q4
Scopus Q Değeri
Q2
Cilt
12
Sayı
4
