The influence of processing parameters on microstructural development of low-weight-percent primary, pro-eutectic, dendritic alloys during directional solidificationAlloy compositions centering about Sn- 5 to 15 wt pct Al and Pb- 4 to 20 wt pct Cu have been directionally solidified as a function of growth rate and orientation with respect to earth's gravity vector. The effect of these processing variables on macrosegregation is presented, and the consequence of a structural transition from primary columnar to equiaxed dendritic growth is examined. Effects detrimental to microstructure and attributed to density variations are shown to be minimized by a novel processing technique. In view of the ground-based results, some considerations follow regarding what might be gained by solidifying these alloys in a microgravity environment.
Document ID
19920043169
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Grugel, R. N. (NASA Headquarters Washington, DC United States)
Kim, Shinwoo (NASA Headquarters Washington, DC United States)
Woodward, Tracey (NASA Headquarters Washington, DC United States)
Wang, T. G. (Vanderbilt University Nashville, TN, United States)