PURIFICATION AND CRYSTALLIZATION OF AMORPHOUS BORON POWDER BY ZONE REFINING PRE- PURIFICATION OF BORON BEFORE ZONING Technical Report: January 21, to July 20, 1965

摘要

This report covers experimental work in conversion of A. E. C. enriched boron, which has been produced in electrolytic cells, to crystalline boron of higher purity.nAmorphous boron-10 powder has been prepared for processing by several methods;isostatic compaction appears to be the most desirable method.nSintering of isostatic compacts at 17000C to 1800°C improves the purity and gives good crystallinity. Multiple float zone passes further improves the purity. Horizontal zoning, employing a water-cooled boat shows considerable promise but requires additional study to evaluate its potential. Simple melting, Czochralski zoning and gradient freezings do not appear to offer as much promise.