Primary dendrite spacing of directionally solidified lead rich Pb--Sn binary alloys

Technical Report · Tue May 01 00:00:00 EDT 1979

DOI:https://doi.org/10.2172/6066690· OSTI ID:6066690

Klaren, C. M.

The primary dendrite spacing (d) of lead rich Pb--Sn alloys resulting from steady state directional solidification was measured as a function of temperature gradient (G), alloy composition (C), and growth velocity (V). The relationship d..cap alpha..G/sup -1/3/ was observed with three different alloy compositions and thermal gradients ranging from 11 to 358/sup 0/C/cm. The effect of increasing solute content in the alloys was inconclusive, although dendrite spacing generally increased. Growth velocities were varied from 1 to 409 ..mu..m/sec in the gradient range from 300 to 400/sup 0/C/cm. At growth velocities less than 45 ..mu..m/sec the dendrite spacings displayed no apparent dependence on the growth rates. This was attributed to the effects of convection and of the concept of a limiting maximum cell spacing as V approaches 0. At growth rates in excess of 45 ..mu..m/sec, a d..cap alpha..V/sup -1/2/ relationship was exhibited. Experimental data were analyzed in terms of several theoretical treatments of dendrite growth. The results indicated that perhaps a more detailed analysis of the problem is necessary in order to encompass the range of growth conditions encountered in this study.

• Research Organization: Ames Lab., Ames, IA (United States)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6066690
• Report Number(s): IS-T-857
• Resource Relation: Other Information: Thesis
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
LEAD BASE ALLOYS
CRYSTAL STRUCTURE
SOLIDIFICATION
TIN ALLOYS
DENDRITES
DENSITY
DESIGN
DIAGRAMS
HIGH TEMPERATURE
INTERFACES
LABORATORY EQUIPMENT
MEDIUM TEMPERATURE
MICROSTRUCTURE
MORPHOLOGY
TEMPERATURE GRADIENTS
ALLOYS
CRYSTALS
LEAD ALLOYS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
360102* - Metals & Alloys- Structure & Phase Studies
360101 - Metals & Alloys- Preparation & Fabrication