Fracture behaviour assessment of the additively manufactured and HPT-processed Al-Si-Cu alloy

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F26316919%3A_____%2F24%3AN0000009" target="_blank" >RIV/26316919:_____/24:N0000009 - isvavai.cz</a>

Result on the web

<a href="https://journals.sagepub.com/doi/10.1177/02670836241262477" target="_blank" >https://journals.sagepub.com/doi/10.1177/02670836241262477</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1177/02670836241262477" target="_blank" >10.1177/02670836241262477</a>

Result language

angličtina

Original language name

Fracture behaviour assessment of the additively manufactured and HPT-processed Al-Si-Cu alloy

Original language description

Ultrafine-grained Al-9%Si-3%Cu alloy was achieved by a combination of laser powder bed fusion (LPBF) additive manufacturing and high-pressure torsion (HPT) processing in this investigation. The alloy was initially deposited layer-by-layer using a bi-directional scan strategy in LPBF with a scan rate of 1000 mms-1, a layer thickness of 40 mu m and a hatch spacing of 200 mu m, leading to a melt pool morphology with an average width of 150 mu m and differing lengths. This led to a grain size of 722 nm and a dislocation density of 1.1 x 1014 m-2. This as-deposited alloy was then processed using HPT at room temperature using an applied pressure of 6.0 GPa and at a speed of one revolution per minute for different numbers of turns: half, one, five and ten turns. The alloy after HPT processing showed ultrafine grains with a grain size of 66 nm, well-dispersed nanosized intermetallic particles with sizes of 50-90 nm, the disappearance of the pool morphology and a notable dislocation density of about 6.2 x 1014 m-2 for the ten turns HPT-processed alloy. The as-deposited and subsequently HPT-processed samples were tensile tested at 298 and 573 K at different strain rates between 10-4 and 10-1 s-1. The elongation-to-failure and tensile strength were recorded and the fracture surfaces were also inspected using scanning electron microscopy and then correlated with the manufacturing, processing and tensile testing conditions. The alloy performance in tensile testing has been evaluated at ambient and elevated temperatures in terms of structural evolution and fractography for the first time. Ultrafine alpha-aluminium grains and nanosized eutectic silicon particles obtained by room temperature HPT-processing of the alloy have significantly improved the mechanical properties and microstructural stability at ambient and elevated testing temperatures for the HPT-processed additively manufactured alloy compared to the as-deposited additively manufactured and counterpart conventional alloys. The HPT-processed tensile samples showed a significant tensile strength of 700 MPa at 298 K and elongation-to-failure of 220% at 573 K, which is higher than that seen in the as-deposited tensile samples where 400 MPa and 106% are observed under the same testing conditions. Fractographic observations demonstrated that mixed brittle and shear ductile fractures dominated in the as-deposited tensile samples at 298 K, and tension ductile fracture dominated at 573 K. However, the HPT-processed tensile samples exhibited tension ductile and shear ductile fractures at 298 K, and tension ductile fracture at 573 K. The ultrafine-grained microstructure produced by the HPT application in the LBPF-manufactured alloy controls effectively the fracture mechanisms, dimple morphology and thus strength and elongation in comparison with the as-deposited additively manufactured microstructure.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

20501 - Materials engineering

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

MATERIALS SCIENCE AND TECHNOLOGY

ISSN

0267-0836

e-ISSN

1743-2847

Volume of the periodical

neuveden

Issue of the periodical within the volume

JUN 2024

Country of publishing house

US - UNITED STATES

Number of pages

22

Pages from-to

nestránkováno

UT code for WoS article

001249114200001

EID of the result in the Scopus database

2-s2.0-85196379356