Original scientific paper
Effect of pre-annealing and pre-cold working on isothermal annealing of (Al + 0.25 wt pct Fe)
M. R. Soliman
; Metal Physics Laboratory, National Research Centre, Cairo
T. H. Youssef
; Metal Physics Laboratory, National Research Centre, Cairo
H. A. Ahmed
; Metal Physics Laboratory, National Research Centre, Cairo
Abstract
Pre-annealing and pre-coldworking were found to have considerable effects on the isothermal characteristics of the deformed (AI + 0.25 Fe). The activation energy of relaxation ranges between 0.38 and 0.72 eV., depending on the thermal and mechanical history of the alloy. The activation energy per unit recovery ∂Q/ ∂R was found to decrease linearly with shear strain γ according to the relation ∂Q/∂R = - α γ¯+ β . This might be due to excess stored energy given by pre-coldworking. The activation energy per unit recovery per unit shear ∂2Q/∂R ∂γ¯ was found to increase with pre-annealing temperature with a relatively slower rate beyond 350 °C. This might be attributed probably to the AI3Fe and Al6Fe phases that form at temperatures beyond 350 °C.
Keywords
pre-annealing; pre-cold working
Hrčak ID:
321433
URI
Publication date:
1.11.1970.
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