Accession Number : AD0608443

Title :   TOPOTACTICAL REARRANGEMENT IN ALC4B24 AND PREPARATION OF A NEW BORON CARBIDE TYPE STRUCTURE.

Descriptive Note : Technical rept. no. 4,

Corporate Author : CARBORUNDUM CO NIAGARA FALLS N Y

Personal Author(s) : Economy,J. ; Matkovich,V. I. ; Giese,R. F. ,Jr.

Report Date : OCT 1964

Pagination or Media Count : 15

Abstract : Single crystals of AlC4B24 undergo an irreversible rearrangement at high temperatures to a boron carbide type structure. During the reaction the form of the original single crystal is not altered, which enables tracing of the crystallographic axes during the transition. The rearrangement can be expressed in terms of a change in packing from hexagonal closest to cubic losest packing of icosahedral boron groups. The boron carbide phase contains a variable amount of aluminum over the composition range of B12C2Al25 - B12C2Al.75. This range is interpreted to be part of a homogeneity range between a boron carbide B12C2 and a ternary phase B12C2Al. (Author)

Descriptors :   (*BORIDES, CRYSTAL STRUCTURE), (*ALUMINUM COMPOUNDS, BORIDES), (*CRYSTAL STRUCTURE, BORIDES), SINGLE CRYSTALS, PHASE STUDIES, BORON COMPOUNDS, CARBIDES, HIGH TEMPERATURE

Distribution Statement : APPROVED FOR PUBLIC RELEASE