FAYÇAL Hadj Larbi University of Sciences and Technology Houari Boumediene

Spoluautoři ABIB K., KHEREDDINE Y., ALILI B., KAWASAKI M., BRADAI D. & LANGDONC T.G.

Severe Plastic Deformation (SPD) methods are extensively used in order to achieve enhanced grain refinement. The Equal-Channel Angular Pressing (ECAP) process is a recently developed method for the homogeneous deformation processing of bulk materials. This promising and attractive technique is increasingly used because recent improvements make it easy adaptable to large-scale industrial processes. Dislocations (with high densities) and vacancies (with high concentrations) are known as the major defects observed in metallic materials processed by SPD techniques such as ECAP and therefore these ultrafine-grained microstructures are often thermally unstable. Post-SPD processing, recovery, recrystallization and grain growth can be documented by accurately monitoring the thermal analysis using Differential Scanning Calorimetry (DSC). In this framework, the present paper describes the use of the DSC technique. The goal of the investigation was to use the DSC technique in order to reveal the deformation phenomena after warm ECAP processing for up to 12 passes using route A where the sample is not rotated between passes. The experiments were conducted using an industrial CuNiSi alloy (SICLANIC S) and the stored energy and the activation energy were estimated. The results show that the stored energy increases upon straining up to 4 passes and then saturates at a value close to ~0.91 J/g. The activation energy after 12 passes was ~120 kJ/mol.

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