Internal Stress Evaluation by Attenuation Measurements during Room Temperature Creep in 5N Aluminium
It is generally well established that the resolved shear stress, due to an applied tensile stress which is large enough in order to induce long-range dislocation movements, can be divided in two components: the first one, τeff., originates from short-range stress obstacles which can be overcome with the help of thermal energy and the second one is due to long-range stress obstacles for which thermal activation is not effective; this latter component leads to the so called “internal stress” (τi). In the past, from relaxation /1/ or creep /2/ tests, various methods have been proposed in order to determine this internal stress. More recently, some evaluations of τi have been carried out by measuring the dislocation loop radius of curvature during T.E.M. observations /3/.
KeywordsPoint Defect Internal Stress Dislocation Loop Ultrasonic Attenuation Applied Tensile Stress
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- /14/.G. GREMAUD, Complex interaction mechanisms between dislocations and point defects involving simultaneously depinning-repinning and dragging processes, J. de Physique C9, 12, 44, 607 (1983).Google Scholar
- /15/.J. CHICOIS, A. HAMEL, R. FOUGERES, C. ESNOUF, G. FANTOZZI and J. PEREZ, Internal Stress measurement in aluminium by Dip Test method and correlation with the Bordoni relaxation evolution, J. de Physique, C5, 10, 42, 169 (1981).Google Scholar
- /17/.C. CRUSSARD, Etude rhéologique du fluage et de l’hystérésis mécanique des matériaux, Métaux, Corrosion, Industrie, 299 (1963–1964).Google Scholar
- /18/.H. OIKAWA AND T; LANGDON, The creep characteristics of pure metals and metallic solid solution alloys, in: “Creep behaviour of crystalline solids”, B. WILSHIRE and R.W. EVANS ed., Pineridge Press, Swansea (1985).Google Scholar