The transition from columnar to equiaxed dendritic growth in proeutectic,low-volume fraction copper,Pb?Cu alloys |
| |
Authors: | Shinwoo Kim R N Grugel |
| |
Affiliation: | (1) Center for Microgravity Research and Applications, Department of Materials Science and Engineering, Vanderbilt University, 37235 Nashville, TN |
| |
Abstract: | Lead, 17.1, 11.2, and 5 volume fraction copper (14, 9, and 4 wt pct Cu) alloys have been directionally solidified at constant
growth velocities ranging from 1 to 100 μm s−1. Serially increasing the growth velocity within this range results in a graded microstructural transition from fully columnar,
albeit segregated, copper dendrites in a lead matrix to one consisting only of equiaxed grains. The imposed velocity necessary
to effect fully equiaxed growth is found to drop rapidly as the volume fraction of copper is decreased. Factors which complicate
the controlled, directional solidification of these alloys are discussed and the experimental results are interpreted in view
of, and seen to be in qualitative agreement with, Hunt’s theory on the transition from columnar to equiaxed growth of dendrites. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|