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Development of Large Bandgap Materials Using Reactive Growth in Al-SI Eutectic for Optical and RF ApplicationsCarbon was utilized as reactive element to modify the microstructure using forced mixing during crystallization of the Al-Si alloy by rotation and stirring. We nucleated the material on SiC substrates while the Al-Si melt was rotated with a speed of 30rpm in a graphite crucible. Several experiments were performed and parameters such as time of mixing, soaking temperature, rotation rate of the substrate and rate of cooling during the solidification was changed. We observed dendrite and cell morphologies during the solidification of rotating melt. The microstructure was characterized by optical microscopy and SEM-EDX and compositional spectroscopy. The effect of carbon impurities was studied on the solidifying microstructure. When we used the longer soak time of the melt in presence of carbon impurities we observed the destruction of dendritic morphology and the formation of cellular and colony structures. Similar approach has been used for Ga2O3, a novel large bandgap material also.
Document ID
20180007871
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Singh, N. B. (Maryland Univ. Baltimore, MD, United States)
Su, Ching-Hua (NASA Marshall Space Flight Center Huntsville, AL, United States)
Gill, Puneet
Choa, Fow-Sen
Arnold, Bradley
Cullum, Brian
Cooper, C.
Mandal, K. D.
Date Acquired
November 27, 2018
Publication Date
October 14, 2018
Subject Category
Inorganic, Organic And Physical Chemistry
Report/Patent Number
M18-6926
Meeting Information
Meeting: Materials Science & Technology (MS&T) 2018
Location: Columbus, OH
Country: United States
Start Date: October 14, 2018
End Date: October 18, 2018
Sponsors: Association for Iron and Steel Technology (AIST), American Ceramic Society, ASM International, Minerals, Metals and Materials Society
Distribution Limits
Public
Copyright
Public Use Permitted.

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