Accession Number : AD0712809

Title :   TRANSMISSION ELECTRON MICROSCOPY STUDY OF Al-Zn-Mg.

Descriptive Note : Technical rept.,

Corporate Author : RENSSELAER POLYTECHNIC INST TROY N Y MATERIALS DIV

Personal Author(s) : Judd,G. ; Shastry,C. R.

Report Date : 09 OCT 1970

Pagination or Media Count : 28

Abstract : The effect of quench rate on the distribution of precipitates in the matrix and at the grain boundaries with special attention to the formation of grain boundary precipitate free zones in an Al-Zn-Mg alloy aged at two different temperatures was studied by transmission electron microscopy. For relatively fast quenched specimens, definite correlation was found to exist between the width of precipitate free zones and the extent of grain boundary precipitation. The variation of precipitate free zone width with quench rate was also found to depend on the grain boundary type. For relatively slow quenched specimens, a fine matrix precipitate distribution with narrow grain boundary precipitate free zones was observed. The results are discussed in terms of the current-theories of precipitation in aluminum alloys. (Author)

Descriptors :   (*ALUMINUM ALLOYS, GRAIN STRUCTURES(METALLURGY)), ELECTRON MICROSCOPY, MICROSTRUCTURE, ZINC ALLOYS, MAGNESIUM ALLOYS, GRAIN BOUNDARIES

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE