Synergistic enhancement of strength-ductility and fatigue crack propagation behavior in powder metallurgy Al-Cu-Mg alloy

Xin Li; Weihao Han; Cunguang Chen; Yang Li; Miao Qi; Ren Zhang; Zhining Nie; Huimin Xia; Fang Yang; Yang Ren; Xinhua Liu; Zhimeng Guo

doi:10.1016/j.msea.2025.148909

Synergistic enhancement of strength-ductility and fatigue crack propagation behavior in powder metallurgy Al-Cu-Mg alloy

Xin Li (Co-first Author)
, Weihao Han (Co-first Author)
, Cunguang Chen^*
, Yang Li
, Miao Qi
, Ren Zhang
, Zhining Nie
, Huimin Xia
, Fang Yang^*
, Yang Ren
, Xinhua Liu^*
, Zhimeng Guo

^*Corresponding author for this work

Department of Physics

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

3 Citations (Scopus)

Abstract

Traditional powder metallurgy (PM) Al-Cu-Mg alloys are prone to fatigue failure due to insufficient mechanical properties. In this work, high-performance Al-Cu-Mg alloy plates through powder metallurgy, hot extrusion and T39 heat treatment were successfully developed, and the fatigue crack propagation behavior was also studied. After T39 heat treatment, grain refinement was achieved in both extrusion and transverse directions, with average grain sizes of 3.51 μm and 3.46 μm, respectively. Nanoscale Al₂Cu and Al₂CuMg precipitates (∼5 nm) were observed within and between grains, along with MgAl₂O₄ and Al₂O₃ particles at sub-grain boundaries. The ultimate tensile strengths were 545 MPa (extrusion direction) and 515 MPa (transverse), with yield strengths of 478 MPa and 409 MPa, and elongations of 10.5 % and 15 %, respectively. Under similar R-values and ΔK levels, fatigue crack growth rates were comparable in both directions. Notably, the crack growth rate was higher at R = 0.5 than at R = −1, attributed to the Schmid factor. Grain refinement, precipitation, and dispersion strengthening collectively enhanced mechanical performance and fatigue resistance. These results provide insights into achieving strength–ductility synergy and improved fatigue resistance in advanced PM Al-Cu-Mg alloys. © 2025 Elsevier B.V.

Original language	English
Article number	148909
Number of pages	14
Journal	Materials Science and Engineering: A
Volume	944
Online published	5 Aug 2025
DOIs	https://doi.org/10.1016/j.msea.2025.148909
Publication status	Published - Nov 2025

Funding

This work was supported by the National Natural Science Foundation of China (Grant Nos. 52271020 , 92266301 and U21A200305), the Science and Technology Research and Development Plan Joint Fund Project in Henan Province of China (Grant No. 225200810065), Introducing Urgently Needed Talents Project for Areas Supported Significantly by Shandong Province of China (Grant No. 2024-3), the Shenzhen Science and Technology Innovation Commission (Grant No. JCYJ20220818101016034), and the City University of Hong Kong (Grant No. CityU 9610533). The strengthening mechanism described in this paper was conducted in the JC STEM Lab of Energy and Materials Physics funded by the Hong Kong Jockey Club Charities Trust.

Research Keywords

Al-Cu-Mg aluminum alloy
Fatigue crack propagation rate
Grains refinement
Hot extrusion
Powder metallurgy

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title = "Synergistic enhancement of strength-ductility and fatigue crack propagation behavior in powder metallurgy Al-Cu-Mg alloy",

abstract = "Traditional powder metallurgy (PM) Al-Cu-Mg alloys are prone to fatigue failure due to insufficient mechanical properties. In this work, high-performance Al-Cu-Mg alloy plates through powder metallurgy, hot extrusion and T39 heat treatment were successfully developed, and the fatigue crack propagation behavior was also studied. After T39 heat treatment, grain refinement was achieved in both extrusion and transverse directions, with average grain sizes of 3.51 μm and 3.46 μm, respectively. Nanoscale Al2Cu and Al2CuMg precipitates (∼5 nm) were observed within and between grains, along with MgAl2O4 and Al2O3 particles at sub-grain boundaries. The ultimate tensile strengths were 545 MPa (extrusion direction) and 515 MPa (transverse), with yield strengths of 478 MPa and 409 MPa, and elongations of 10.5 \% and 15 \%, respectively. Under similar R-values and ΔK levels, fatigue crack growth rates were comparable in both directions. Notably, the crack growth rate was higher at R = 0.5 than at R = −1, attributed to the Schmid factor. Grain refinement, precipitation, and dispersion strengthening collectively enhanced mechanical performance and fatigue resistance. These results provide insights into achieving strength–ductility synergy and improved fatigue resistance in advanced PM Al-Cu-Mg alloys. {\textcopyright} 2025 Elsevier B.V.",

keywords = "Al-Cu-Mg aluminum alloy, Fatigue crack propagation rate, Grains refinement, Hot extrusion, Powder metallurgy",

author = "Xin Li and Weihao Han and Cunguang Chen and Yang Li and Miao Qi and Ren Zhang and Zhining Nie and Huimin Xia and Fang Yang and Yang Ren and Xinhua Liu and Zhimeng Guo",

year = "2025",

month = nov,

doi = "10.1016/j.msea.2025.148909",

language = "English",

volume = "944",

journal = "Materials Science and Engineering: A",

issn = "0921-5093",

publisher = "Elsevier Ltd.",

}

Synergistic enhancement of strength-ductility and fatigue crack propagation behavior in powder metallurgy Al-Cu-Mg alloy. / Li, Xin (Co-first Author); Han, Weihao (Co-first Author); Chen, Cunguang et al.
In: Materials Science and Engineering: A, Vol. 944, 148909, 11.2025.

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

TY - JOUR

T1 - Synergistic enhancement of strength-ductility and fatigue crack propagation behavior in powder metallurgy Al-Cu-Mg alloy

AU - Li, Xin

AU - Han, Weihao

AU - Chen, Cunguang

AU - Li, Yang

AU - Qi, Miao

AU - Zhang, Ren

AU - Nie, Zhining

AU - Xia, Huimin

AU - Yang, Fang

AU - Ren, Yang

AU - Liu, Xinhua

AU - Guo, Zhimeng

PY - 2025/11

Y1 - 2025/11

N2 - Traditional powder metallurgy (PM) Al-Cu-Mg alloys are prone to fatigue failure due to insufficient mechanical properties. In this work, high-performance Al-Cu-Mg alloy plates through powder metallurgy, hot extrusion and T39 heat treatment were successfully developed, and the fatigue crack propagation behavior was also studied. After T39 heat treatment, grain refinement was achieved in both extrusion and transverse directions, with average grain sizes of 3.51 μm and 3.46 μm, respectively. Nanoscale Al2Cu and Al2CuMg precipitates (∼5 nm) were observed within and between grains, along with MgAl2O4 and Al2O3 particles at sub-grain boundaries. The ultimate tensile strengths were 545 MPa (extrusion direction) and 515 MPa (transverse), with yield strengths of 478 MPa and 409 MPa, and elongations of 10.5 % and 15 %, respectively. Under similar R-values and ΔK levels, fatigue crack growth rates were comparable in both directions. Notably, the crack growth rate was higher at R = 0.5 than at R = −1, attributed to the Schmid factor. Grain refinement, precipitation, and dispersion strengthening collectively enhanced mechanical performance and fatigue resistance. These results provide insights into achieving strength–ductility synergy and improved fatigue resistance in advanced PM Al-Cu-Mg alloys. © 2025 Elsevier B.V.

AB - Traditional powder metallurgy (PM) Al-Cu-Mg alloys are prone to fatigue failure due to insufficient mechanical properties. In this work, high-performance Al-Cu-Mg alloy plates through powder metallurgy, hot extrusion and T39 heat treatment were successfully developed, and the fatigue crack propagation behavior was also studied. After T39 heat treatment, grain refinement was achieved in both extrusion and transverse directions, with average grain sizes of 3.51 μm and 3.46 μm, respectively. Nanoscale Al2Cu and Al2CuMg precipitates (∼5 nm) were observed within and between grains, along with MgAl2O4 and Al2O3 particles at sub-grain boundaries. The ultimate tensile strengths were 545 MPa (extrusion direction) and 515 MPa (transverse), with yield strengths of 478 MPa and 409 MPa, and elongations of 10.5 % and 15 %, respectively. Under similar R-values and ΔK levels, fatigue crack growth rates were comparable in both directions. Notably, the crack growth rate was higher at R = 0.5 than at R = −1, attributed to the Schmid factor. Grain refinement, precipitation, and dispersion strengthening collectively enhanced mechanical performance and fatigue resistance. These results provide insights into achieving strength–ductility synergy and improved fatigue resistance in advanced PM Al-Cu-Mg alloys. © 2025 Elsevier B.V.

KW - Al-Cu-Mg aluminum alloy

KW - Fatigue crack propagation rate

KW - Grains refinement

KW - Hot extrusion

KW - Powder metallurgy

UR - https://www.scopus.com/pages/publications/105012433089

UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-105012433089&origin=recordpage

U2 - 10.1016/j.msea.2025.148909

DO - 10.1016/j.msea.2025.148909

M3 - RGC 21 - Publication in refereed journal

SN - 0921-5093

VL - 944

JO - Materials Science and Engineering: A

JF - Materials Science and Engineering: A

M1 - 148909

ER -

Synergistic enhancement of strength-ductility and fatigue crack propagation behavior in powder metallurgy Al-Cu-Mg alloy

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