Formation of recrystallization textures in rolled aluminum single crystals

Scripta M E T A L L U R G I C A

Vol. 9, pp. xlv-xlvi, 1975 Printed in the United States

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ACTA M E T A L L U R G I C A "Acta Met. (to be published)" should be cited in references to material quoted from this section prior to the publication of the relevant article.

I.

Received December 23, 1974

FORMATION OF RECRYSTALLIZATION TEXTURES IN ROLLED ALUMINUM SINGLE CRYSTALS K. LUCKE', R. RIXEN * & M. SENNA~* ' Institut f. Allgemeine Metallkunde und Metallphysik der Technischen Hochschule Aachen, Germany. • now at VAW Leichtmetall GmbH, Grevenbroich, Germany. ~* As a guest from Keio University, Faculty of Engineering, Hiyoshi, Japan. Received September 13, 1974 Revised May 14, 1975

The use of differential scanning calorimetry with a rapid cool to isothermal hold temperature program provides a convenient, rapid, and accurate method for monitoring emulsion droplet nucleation. This type of isothermal nucleation rate measurement corresponds to the classical isothermal dilatomotric method. Differential scanning calorimetry can also be used to monitor constant cooling heat release from emulsion droplet crystallization to provide in a single experiment a method for calculating the temperature dependence of the nucleation rate. This second use of DSC corresponds to the constant cooling microscopic methods for measuring the temperature dependence of the nucleation rate. The nucleation kinetics for the liquid to solid transformation have been monitored by both differential scanning calorimetric methods for emulsions of a droplet of an alloy (90% tin10% bismuth). The results are consistent with a homogeneous nucleation mechanism for generating the nuclei.

Rolling and recrystallization textures of M-single crystals have been measured with great accuracy. In all cases a' clear 40°<111> orientation relationship was found. An analysis of these results and also of those of the literature led to the conclusion (i) that this relationship is definitely a result of oriented growth, (ii) that the nuclei effective in the present experiments were part of the deformed matrix with orientations near the edge of the spread of the deformation textures, and (iii) that the selection of the observed + 40° 3. orientations out of the eight possible ones is determined by the availability of nuclei. Strong arguments were found that, in contrast to recent opinion, also in polycrystalline al~ninum oriented growth is largely responsible for the observed recrystallization textures.

ORIENTATIONDEPENDENCE OF GRAIN-BOONDARY ENERGY IN METALS IN THE VIEW OF A PSEUDOHETEROPHASE DISLOCATIONCORE MODEL W. MISSOL Institute of Nonferrous Metals, 44-101 Gliwice, Poland. Received February 15, 1975 Revised June 16, 1975

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DSC: A RAPID METHOD FOR ISOTHERMAL NUCLEATION RATE MEASUREMENT D. H. RASMUSSFJN & C. R. LOPER JR. Cryobiology Research Institute, Madison, Wis., and the Materials Science Program, Dept, of Metals and Minerals Eng., University of Wiscong~n, Madison, Wis.

A new dislocation model for symnetric tilt g r a i n boundaries was developed as a b a s i s for d e r i v i n g the q u a n t i t a t i v e dependence of g r a i n boundary energy upon m i s o r i e n t a t i o n angle i n the form of an expression s i m i l a r to t h a t given by Read and Shockley. The range of a p p l i c a b i l : i t y of t h i s equation was extended to over 20 deg. A comparison of theory and experiment f o r Bi, Ag, Cu, FeSi 3% i n the 'teen-degrees range of m i s o r i e n t a t i o n angles and for Au, a-Fe, )4o,

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