Title

THE EFFECT OF SECOND PHASE PRECIPITATES ON THE WORK- HARDENING BEHAVIOUR OF ECAP-DEFORMED Al ALLOYS

THE EFFECT OF SECOND PHASE PRECIPITATES ON THE WORK- HARDENING BEHAVIOUR OF ECAP-DEFORMED Al ALLOYS

Authorship

Prados, E.F.; Sordi, V.L.; Ferrante, M.

Prados, E.F.

I am this author

Sordi, V.L.

I am this author

Ferrante, M.

I am this author

DOI

10.5151/2594-5327-32547

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Abstract

A characteristic of metallic materials subjected to severe plastic deformation is a sharp decrease of work-hardening capacity. This reflects negatively on the ductility although there is some experimental evidence that ductility enhancing mechanisms can be activated. Among those, it appears that precipitates and dispersoids have some success, and the present study analyzes strength and work hardening behaviour of a ECAP-deformed Al-4%Cu alloy. Deformation was followed by a combination of precipitation/annealing heat treatments designed to produce a range of microstructures containing or formed by: (i) very large Al2Cu precipitates; (ii) small, peak strength precipitates; (iii) solid solution. Tensile test data of the various conditions were analyzed in conjunction with the corresponding microstructure. Results show that Al2Cu precipitates contributed to increase the work-hardening capacity of the Al-Cu system, either by increasing the dislocation density, or by pinning these defects and keeping them inside the grains, or both.

A characteristic of metallic materials subjected to severe plastic deformation is a sharp decrease of work-hardening capacity. This reflects negatively on the ductility although there is some experimental evidence that ductility enhancing mechanisms can be activated. Among those, it appears that precipitates and dispersoids have some success, and the present study analyzes strength and work hardening behaviour of a ECAP-deformed Al-4%Cu alloy. Deformation was followed by a combination of precipitation/annealing heat treatments designed to produce a range of microstructures containing or formed by: (i) very large Al2Cu precipitates; (ii) small, peak strength precipitates; (iii) solid solution. Tensile test data of the various conditions were analyzed in conjunction with the corresponding microstructure. Results show that Al2Cu precipitates contributed to increase the work-hardening capacity of the Al-Cu system, either by increasing the dislocation density, or by pinning these defects and keeping them inside the grains, or both.

Keywords

ECAP; Al-Cu; precipitation; work-hardening.

ECAP; Al-Cu; precipitation; work-hardening.