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On the recrystallization of metals in the emission electron microscope
Author(s) -
Soa E.A.
Publication year - 1971
Publication title -
kristall und technik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0023-4753
DOI - 10.1002/crat.19710060609
Subject(s) - recrystallization (geology) , tungsten , grain boundary , molybdenum , materials science , electron , electron microscope , crystallography , crystallite , metallurgy , chemistry , microstructure , optics , paleontology , biology , physics , quantum mechanics
By the emission electron microscope a high‐contrast picture of grain structure is obtained with thermal or photoelectric release of electrons. The „memory effect” (M ORLIN , T REMMEL ) marks the individual steps of the grain boundary movement through volume expansion or thermal etching when releasing electrons by electrons or ions. The existence of an oxide layer on the surface of e.g. molybdenum and tungsten is starting the recrystallization and influencing the recrystallization temperature. Oxide layers are formed in selected areas corresponding to the distribution of surface seeds and the oxygen bombardment. Carbon atoms accumulate preferably at the grain boundaries as carbides, so decorating the crystallites in forming mixed crystals. – It may be assumed that the carbon solved in tungsten and molybdenum fixes the dislocations at the grain boundaries. In contradiction to all theories of secondary recrystallization „ring crystals” are formed.