TY - JOUR

T1 - The effect of hardening by annealing in ultrafine-grained Al-0.4Zr alloy: influence of Zr microadditives

AU - Latynina, T. A.

AU - Mavlyutov, A. M.

AU - Murashkin, M. Yu

AU - Valiev, R. Z.

AU - Orlova, T.  S.

N1 - Funding Information: This work was supported by the Russian Foundation for Basic Research [project No. 19-08-00474]. Anvils for HPT tool were produced in collaboration with the centre ?Applied aerodynamics? of the Research Park of St.?Petersburg State University. Publisher Copyright: © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.

PY - 2019

Y1 - 2019

N2 - Influence of annealing on the microstructure and mechanical properties has been studied for Al-Zr (0.4 wt.%) alloy with the ultrafine-grained (UFG) structure formed by high-pressure torsion (HPT) at room temperature. A drastic hardening effect by short-term annealing in the temperature range of 90-280 degrees C was observed for the HPT-processed Al-Zr alloy. The effect of hardening by annealing for the HPT-processed Al-Zr alloy is compared with that for the HPT-processed commercial purity (CP) Al. It was shown that addition of 0.4 wt.% Zr in Al does not cause a significant impact on the magnitude of hardening by annealing up to 150 degrees C, however it leads to a shift of its maximum to higher annealing temperatures and expansion of the thermal stability range of strength up to 280 degrees C. The kinetics of hardening by annealing for CP Al and Al-Zr alloys in the UFG state has been studied for the first time. It was shown that in both materials the strength first increases linearly with the duration of annealing and then reaches saturation. The temperature dependence of the rate of hardening by annealing was analysed through an Arrhenius law, and apparent activation energy was extracted for both systems. The addition of Zr results in the reduction of the activation energy of annealing-induced hardening by similar to 2 times. Possible physical mechanisms controlling the kinetics of hardening by annealing are discussed for the ultrafine-grained CP Al and Al-Zr alloy.

AB - Influence of annealing on the microstructure and mechanical properties has been studied for Al-Zr (0.4 wt.%) alloy with the ultrafine-grained (UFG) structure formed by high-pressure torsion (HPT) at room temperature. A drastic hardening effect by short-term annealing in the temperature range of 90-280 degrees C was observed for the HPT-processed Al-Zr alloy. The effect of hardening by annealing for the HPT-processed Al-Zr alloy is compared with that for the HPT-processed commercial purity (CP) Al. It was shown that addition of 0.4 wt.% Zr in Al does not cause a significant impact on the magnitude of hardening by annealing up to 150 degrees C, however it leads to a shift of its maximum to higher annealing temperatures and expansion of the thermal stability range of strength up to 280 degrees C. The kinetics of hardening by annealing for CP Al and Al-Zr alloys in the UFG state has been studied for the first time. It was shown that in both materials the strength first increases linearly with the duration of annealing and then reaches saturation. The temperature dependence of the rate of hardening by annealing was analysed through an Arrhenius law, and apparent activation energy was extracted for both systems. The addition of Zr results in the reduction of the activation energy of annealing-induced hardening by similar to 2 times. Possible physical mechanisms controlling the kinetics of hardening by annealing are discussed for the ultrafine-grained CP Al and Al-Zr alloy.

KW - Aluminium alloys

KW - ultrafine grained structure

KW - hardening by annealing

KW - non-equilibrium grain boundaries

KW - strength

KW - electrical resistivity

KW - ELECTRICAL-CONDUCTIVITY

KW - MECHANICAL-PROPERTIES

KW - HIGH-STRENGTH

KW - AL-ALLOYS

KW - MICROSTRUCTURE

KW - DEFORMATION

KW - DIFFUSION

KW - TEMPERATURE

KW - RESISTIVITY

KW - RELAXATION

UR - http://www.scopus.com/inward/record.url?scp=85067835772&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/effect-hardening-annealing-ultrafinegrained-al04zr-alloy-influence-zr-microadditives

U2 - 10.1080/14786435.2019.1631501

DO - 10.1080/14786435.2019.1631501

M3 - статья

AN - SCOPUS:85067835772

VL - 99

SP - 2424

EP - 2443

JO - Philosophical Magazine

JF - Philosophical Magazine

SN - 1478-6435

IS - 19

ER -