Load shuffling during creep deformation of an additively manufactured AlCuMnZr alloy

Richard A. Michi; Sumit Bahl; Christopher M. Fancher; Kevin Sisco; Lawrence F. Allard; Ke An; Dunji Yu; Ryan R. Dehoff; Alex Plotkowski; Amit Shyam

doi:10.1016/j.actamat.2022.118557

Load shuffling during creep deformation of an additively manufactured AlCuMnZr alloy

Research output: Contribution to journal › Article › peer-review

39 Scopus citations

Abstract

The high-temperature deformation behavior of an additively manufactured Al-Cu-Mn-Zr alloy is evaluated in the as-fabricated and heat-treated states using traditional ex-situ and in-situ neutron diffraction creep experiments performed at 300 °C. The dominant reinforcement phase in the alloy, θ-Al₂Cu, despite its high volume fraction of ∼10%, does not provide load transfer strengthening during creep deformation. Instead, the lattice strain evolution suggests a new mechanism we term “load shuffling” wherein the initial load is transferred away from precipitate-free zones along the grain boundaries where most of the θ-Al₂Cu particles are located to precipitate-strengthened grain interiors. Notwithstanding the lack of load transfer strengthening, the as-fabricated AM Al-Cu-Mn-Zr alloy still possesses improved creep resistance at 300 °C relative to a cast alloy with similar composition. The proposed load shuffling mechanism explains the lack of observed L1₂-Al₃Zr strengthening at 300 °C and helps identify several strategies for improvement of elevated-temperature mechanical response of AM Al alloys.

Original language	English
Article number	118557
Journal	Acta Materialia
Volume	244
DOIs	https://doi.org/10.1016/j.actamat.2022.118557
State	Published - Jan 1 2023

Funding

Research was co-sponsored the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office and Vehicle Technologies Office's Powertrain Materials Core Program. APT was conducted at ORNL's Center for Nanophase Materials Sciences (CNMS), which is a U.S. DOE Office of Science User Facility. Authors acknowledge David Dunand and Jovid Rakhmonov (both of Northwestern University) for discussions and Alice Perrin and Yukinori Yamamoto (both of ORNL) for reviewing the manuscript. The authors would like to thank Christina Austin, Kelsey Hedrick, and Shane Hawkins for assistance with mechanical testing, Dana McClurg for performing the heat treatments, and Travis Dixon for electropolishing STEM samples.

Keywords

Additive manufacturing
Aluminum alloys
Creep
Load transfer
Neutron diffraction

Access to Document

10.1016/j.actamat.2022.118557

Cite this

@article{fa234e16611c4257ab67b2c577778f70,

title = "Load shuffling during creep deformation of an additively manufactured AlCuMnZr alloy",

abstract = "The high-temperature deformation behavior of an additively manufactured Al-Cu-Mn-Zr alloy is evaluated in the as-fabricated and heat-treated states using traditional ex-situ and in-situ neutron diffraction creep experiments performed at 300 °C. The dominant reinforcement phase in the alloy, θ-Al2Cu, despite its high volume fraction of ∼10\%, does not provide load transfer strengthening during creep deformation. Instead, the lattice strain evolution suggests a new mechanism we term {\textquotedblleft}load shuffling{\textquotedblright} wherein the initial load is transferred away from precipitate-free zones along the grain boundaries where most of the θ-Al2Cu particles are located to precipitate-strengthened grain interiors. Notwithstanding the lack of load transfer strengthening, the as-fabricated AM Al-Cu-Mn-Zr alloy still possesses improved creep resistance at 300 °C relative to a cast alloy with similar composition. The proposed load shuffling mechanism explains the lack of observed L12-Al3Zr strengthening at 300 °C and helps identify several strategies for improvement of elevated-temperature mechanical response of AM Al alloys.",

keywords = "Additive manufacturing, Aluminum alloys, Creep, Load transfer, Neutron diffraction",

author = "Michi, \{Richard A.\} and Sumit Bahl and Fancher, \{Christopher M.\} and Kevin Sisco and Allard, \{Lawrence F.\} and Ke An and Dunji Yu and Dehoff, \{Ryan R.\} and Alex Plotkowski and Amit Shyam",

note = "Publisher Copyright: {\textcopyright} 2022 Acta Materialia Inc.",

year = "2023",

month = jan,

day = "1",

doi = "10.1016/j.actamat.2022.118557",

language = "English",

volume = "244",

journal = "Acta Materialia",

issn = "1359-6454",

publisher = "Elsevier",

}

TY - JOUR

T1 - Load shuffling during creep deformation of an additively manufactured AlCuMnZr alloy

AU - Michi, Richard A.

AU - Bahl, Sumit

AU - Fancher, Christopher M.

AU - Sisco, Kevin

AU - Allard, Lawrence F.

AU - An, Ke

AU - Yu, Dunji

AU - Dehoff, Ryan R.

AU - Plotkowski, Alex

AU - Shyam, Amit

PY - 2023/1/1

Y1 - 2023/1/1

N2 - The high-temperature deformation behavior of an additively manufactured Al-Cu-Mn-Zr alloy is evaluated in the as-fabricated and heat-treated states using traditional ex-situ and in-situ neutron diffraction creep experiments performed at 300 °C. The dominant reinforcement phase in the alloy, θ-Al2Cu, despite its high volume fraction of ∼10%, does not provide load transfer strengthening during creep deformation. Instead, the lattice strain evolution suggests a new mechanism we term “load shuffling” wherein the initial load is transferred away from precipitate-free zones along the grain boundaries where most of the θ-Al2Cu particles are located to precipitate-strengthened grain interiors. Notwithstanding the lack of load transfer strengthening, the as-fabricated AM Al-Cu-Mn-Zr alloy still possesses improved creep resistance at 300 °C relative to a cast alloy with similar composition. The proposed load shuffling mechanism explains the lack of observed L12-Al3Zr strengthening at 300 °C and helps identify several strategies for improvement of elevated-temperature mechanical response of AM Al alloys.

AB - The high-temperature deformation behavior of an additively manufactured Al-Cu-Mn-Zr alloy is evaluated in the as-fabricated and heat-treated states using traditional ex-situ and in-situ neutron diffraction creep experiments performed at 300 °C. The dominant reinforcement phase in the alloy, θ-Al2Cu, despite its high volume fraction of ∼10%, does not provide load transfer strengthening during creep deformation. Instead, the lattice strain evolution suggests a new mechanism we term “load shuffling” wherein the initial load is transferred away from precipitate-free zones along the grain boundaries where most of the θ-Al2Cu particles are located to precipitate-strengthened grain interiors. Notwithstanding the lack of load transfer strengthening, the as-fabricated AM Al-Cu-Mn-Zr alloy still possesses improved creep resistance at 300 °C relative to a cast alloy with similar composition. The proposed load shuffling mechanism explains the lack of observed L12-Al3Zr strengthening at 300 °C and helps identify several strategies for improvement of elevated-temperature mechanical response of AM Al alloys.

KW - Additive manufacturing

KW - Aluminum alloys

KW - Creep

KW - Load transfer

KW - Neutron diffraction

UR - https://www.scopus.com/pages/publications/85143128005

U2 - 10.1016/j.actamat.2022.118557

DO - 10.1016/j.actamat.2022.118557

M3 - Article

AN - SCOPUS:85143128005

SN - 1359-6454

VL - 244

JO - Acta Materialia

JF - Acta Materialia

M1 - 118557

ER -

Load shuffling during creep deformation of an additively manufactured AlCuMnZr alloy

Abstract

Funding

Keywords

Access to Document

Other files and links

Fingerprint

Cite this