日本金属学会誌

J. Japan Inst. Metals, Vol. 70, No. 1 (2006),
pp. 73-79

Characterization of Coupled-Zone in Sn-Cu Binary Eutectic Alloys Using Unidirectional Solidification

Junichi Machida, Hisao Esaka, Manabu Tamura and Kei Shinozuka

Department of Materials Science and Engineering, National Defense Academy, Yokosuka 239-8686

Abstract:

The Sn-Cu binary eutectic alloy is one of candidate alloys for lead-free solder. In order to investigate the evolution of solidified structure of Sn-Cu binary eutectic alloy, the unidirectional solidification technique has been applied using a Bridgman type furnace.
Primary β-Sn exhibits dendrite morphology, on the other hand, a primary Cu6Sn5 indicates a faceted crystal, the cross section of which is typically H-shaped and eutectic structure is rod-like. Coupled growth zone of this alloy system is found to be extended to Cu-rich side and to be rather symmetric. This may be due to the difference in undercooling for growth of Cu6Sn5, β-Sn and eutectic phases. Jackson parameter of Cu6Sn5 is deduced to be high comparing with β-Sn.


(Received 2005/5/26)

Keywords:

coupled-zone, lead-free solder, undercooling, unidirectional solidification, eutectic growth


PDF(Free)PDF (Free)     Table of ContentsTable of Contents

Please do not copy without permission.