| Title |
Unidirectional Solidification of Al - Cu off - Eutectic |
| Authors |
박노광(No Kwang Park); 김종희(Chong Hee Kim) |
| Abstract |
The Production of materials with composite structure from off-eutectic alloys was investigated. In this work, commercially pure aluminum-copper alloys with compositions on the aluminum-rich side of the eutectic point were solidified vertically under the conditions of controlled crystal growth rate (R) and temperature gradient (G). The value of G/R ratio was between 10²∼10⁴℃/㎠/sec. In the range of the composition from 33 to 33.5 wt. percent copper, `coupled growth` was fully achieved even when the value of G/R approached to zero. The relationship between the interlamellar spacing (λ) within the colony structure and the crystal growth rate was represented by λ²R=1.8x10^(-10)㎤/sec. And the off-eutectic alloys which exhibit eutectic or colony structure behaved as reinforcing composite materials, with the increasing fracture strength and fracture strain as the interlamellar spacing decreases. |