Quantitative analysis of solution hardening in selected copper alloys

doi:10.1016/0001-6160(87)90267-7

Acta Metallurgica

Volume 35, Issue 11, November 1987, Pages 2679-2693

Dedicated to Professor P. Haasen on the occasion of his 60th anniversary.

https://doi.org/10.1016/0001-6160(87)90267-7 Get rights and content

Abstract

Systematic investigations of substitutional solution hardening are reported for f.c.c. systems particularly suited for a quantitative analysis with the Fleischer-Friedel theory. The application of a physically founded potential function for the interaction of glide barriers with edge dislocations proves as important. For $Cu$ Ge and $Cu$ Mn, the latter system satisfying best the requirements of theory, thermodynamic parameters for dislocation glide are determined with high reliability by an iterative procedure jointly analysing τ₀(T)- andV(T)-data. Density and distance of the discrete glide barriers are deduced and arguments put forward that mainly doublets ( $Cu$ Mn) and triplets ( $Cu$ Ge) represent the effective glide barriers in these systems. Low temperature anomalies (inertial and quantum effects), an athermal stress component of the crss, the concentration dependence of effective stress at T = 0, the stress dependence of activation volume and the stress equivalence are discussed.

Résumé

Nous présentons les résultats d'études systématiques réalisées sur le durcissement par mise en solution de substitution dans le cas de systèmes cfc particulièrement bien adaptés à une analyse quantitative avec la théorie de Fleischer et de Friedel. L'application d'une fonction de potentiel physiquement fondée pour décrire l'interaction des barrières de glissement avec les dislocations coins s'avère importante. Pour $Cu$ Ge et $Cu$ Mn (le second système satisfaisant mieux les conditions de la théorie), nous déterminons de façon très sûre les paramètres thermodynamiques du glissement des dislocations à l'aide d'une procédure intérative qui analyse à la fois les données τ₀(T) et V(T). Nous en déduisons la densité et l'espacement des barrières individuelles de glissement, et nous montrons que ce sont principalement des doublets ( $Cu$ Mn) et des triplets ( $Cu$ Ge) qui constituent les barrières efficaces dans ces systèmes. Nous discutons les anomalies observées à basse température (effets quantiques et inertiels), une composante athermique de la cission critique réduite, l'influence de la concentration sur la contrainte effective à T = 0, l'influence de la contrainte sur le volume d'activation, et l'équivalence de la contrainte.

Zusammenfassung

Es wird über systematische Untersuchungen der Mischkristallhärtung von k.f.z. Legierungen berichtet, die die Voraussetzung für eine quantitative Analyse mit der Fleischer-Friedel Theorie besonders gut erfüllen. Die Verwendung einer physikalisch begründeten Beziehung für den Gesamtverlauf des Potentials der Gleitbarrieren erweist sich als wichtig. Die thermodynamischen Parameter werden für Legierungen aus $Cu$ Mn, das am besten geeignete System, und aus $Cu$ Ge mit hoher Zuverlässigkeit aus einem iterativen Verfahren ermittelt, bei dem kritische Schubspannung τ₀(T) und Aktivierungsvolumen V(T) gekoppelt ausgewertet werden. Dichte und mittlerer Abstand der Gleitbarrieren werden abgeleitet, und es wird näher begründet, daβ wahrscheinlich Mn-Paare und Ge-Tripel im wesentlichen die effektiven Barrieren darstellen. Ferner wird näher eingegangen auf die athermische Spannungskomponente der kritischen Schubspannung, die Tieftemperaturanomalien (Trägheits- und Quanteneffekte), die Konzentrationsabhängigkeit der effektiven Spannung bei T = 0, die Spannungsabhängigkeit des Aktivierungsvolumens und auf die Regel der Spanungsäquivalenz.

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^‡: Present address: Applikationslabor, Valvo, D-2000 Hamburg, F.R.G.

^§: Present address: Institut für Werkstoffe, Technische Universität, D-3300 Braunschweig, F.R.G.

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Quantitative analysis of solution hardening in selected copper alloys

Abstract

Résumé

Zusammenfassung

Metall. Trans.

Scripta metall.

Sov. J. Low Temp. Phys.

J. Magnetism Magnet. Mater.

Phys. Rev.

Phil. Mag.

Can. J. Phys.

Scripta metall.

Scripta metall.

Z. Metallk.

Z. Metallk.

Czech. J. Phys.

Phil. Mag.

J. appl. Phys.

J. appl. Phys.

Soviet Phys. Usp.

Verhandl. DPG (VI)

Physica status solidi (a)

Physica status solidi

Acta metall.

Acta metall.

Phil. Mag.

Acta metall.

Acta metall.

Acta metall.

Acta metall.

Mater. Sci. Engng

Phys. Rev.

Phys. Rev. Lett.

J. Mater. Sci.

Acta metall.

Acta metall.

Les Dislocations