TY - JOUR
T1 - Fine-grained aluminium crossover alloy for high-temperature sheet forming
AU - Samberger, Sebastian
AU - Weißensteiner, Irmgard
AU - Stemper, Lukas
AU - Kainz, Christina
AU - Uggowitzer, Peter
AU - Pogatscher, Stefan
N1 - Publisher Copyright:
© 2023 The Author(s)
PY - 2023/4/19
Y1 - 2023/4/19
N2 - This study presents age-hardenable, fine-grained AlMgZnCu crossover alloys intended for superplastic and quick plastic forming processes. The study utilizes T-phase (Mg32(Al,Zn)49) for both grain refinement and age-hardening. It deploys a uniform distribution of µm-sized T-phase particles, which can be dissolved upon final solution annealing, and which is utilized for heavy particle stimulated nucleation (PSN) during industrial processing of sheets, in order to reach an equiaxed grain size as low as 4 µm. This fine grain size is advantageous for high-temperature forming of aluminium alloys. Elongations above 200% and 400% are achieved when deformed at strain rates of 10−2 s−1 or 5*10−5 s−1 at 470 °C, and interestingly, the fine grain structure is highly stable even when held at that temperature for one day. Moreover, the material reached yield strength values of more than 380 MPa after a paint-bake heat treatment for quenching in water or compressed air. The study demonstrates the importance of PSN using electron microscopic and texture measurements and describes it by simple modelling of T-phase particle grain refinement. It explores the high stability of the fine grain assembly in terms of the random grain boundary misorientation distribution in combination with high solute content observed, provided via the dissolved T-phase, and Smith-Zener pinning. The simple, commercially available grain refinement strategy demonstrated using the dissolvable T-phase, and the resulting unique property profile, make the crossover alloy in question a promising candidate for high-temperature sheet forming processes.
AB - This study presents age-hardenable, fine-grained AlMgZnCu crossover alloys intended for superplastic and quick plastic forming processes. The study utilizes T-phase (Mg32(Al,Zn)49) for both grain refinement and age-hardening. It deploys a uniform distribution of µm-sized T-phase particles, which can be dissolved upon final solution annealing, and which is utilized for heavy particle stimulated nucleation (PSN) during industrial processing of sheets, in order to reach an equiaxed grain size as low as 4 µm. This fine grain size is advantageous for high-temperature forming of aluminium alloys. Elongations above 200% and 400% are achieved when deformed at strain rates of 10−2 s−1 or 5*10−5 s−1 at 470 °C, and interestingly, the fine grain structure is highly stable even when held at that temperature for one day. Moreover, the material reached yield strength values of more than 380 MPa after a paint-bake heat treatment for quenching in water or compressed air. The study demonstrates the importance of PSN using electron microscopic and texture measurements and describes it by simple modelling of T-phase particle grain refinement. It explores the high stability of the fine grain assembly in terms of the random grain boundary misorientation distribution in combination with high solute content observed, provided via the dissolved T-phase, and Smith-Zener pinning. The simple, commercially available grain refinement strategy demonstrated using the dissolvable T-phase, and the resulting unique property profile, make the crossover alloy in question a promising candidate for high-temperature sheet forming processes.
UR - http://www.scopus.com/inward/record.url?scp=85153535508&partnerID=8YFLogxK
U2 - 10.1016/j.actamat.2023.118952
DO - 10.1016/j.actamat.2023.118952
M3 - Article
SN - 1359-6454
VL - 253.2023
JO - Acta materialia
JF - Acta materialia
IS - 1 July
M1 - 118952
ER -