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Full-Text Articles in Engineering
Influence Of Natural Convection During Dendritic Array Growth Of Metal Alloys (Gradient Freeze Directional Solidification), Suyog N. Mahajan
Influence Of Natural Convection During Dendritic Array Growth Of Metal Alloys (Gradient Freeze Directional Solidification), Suyog N. Mahajan
ETD Archive
Purpose of this study was to examine the microstructural evolution of primary dendrites during Gradient Freeze Directional Solidification process in cylindrical Pb-5.8% Sb alloy samples to generate the ground- based research data to support a future microgravity experiment on the Space Station in a convection free environment. Pb-5.8Sb was selected for this study because of its ease of processing and availability of physical property data which will be required for predicting the dendrite morphology parameters, such as, primary dendrite spacing and dendrite trunk diameter. This alloy is also susceptible to thermosolutal convection caused by density inversion of the met in …
Effect Of Convection Associated With Cross-Section Change During Directional Solidification Of Binary Alloys On Dendritic Array Morphology And Macrosegregation, Masoud Ghods
ETD Archive
This dissertation explores the role of different types of convection on macrosegregation and on dendritic array morphology of two aluminum alloys directionally solidified through cylindrical graphite molds having both cross-section decrease and increase. Al- 19 wt. % Cu and Al-7 wt. % Si alloys were directionally solidified at two growth speed of 10 and 29.1 µm s-1 and examined for longitudinal and radial macrosegregation, and for primary dendrite spacing and dendrite trunk diameter.
Directional solidification of these alloys through constant cross-section showed clustering of primary dendrites and parabolic-shaped radial macrosegregation profile, indicative of “steepling convection” in the mushy-zone. The degree …