TY - JOUR

T1 - Enhancement in strength and thermal stability of selective laser melted Al–12Si by introducing titanium nanoparticles

AU - Qi, Junfang

AU - Liu, C. Y.

AU - Chen, Z. W.

AU - Liu, Z. Y.

AU - Tian, J. S.

AU - Feng, Jicai

AU - Okulov, I. V.

AU - Eckert, Jürgen

AU - Wang, Pei

N1 - Publisher Copyright: © 2022 Elsevier B.V.

PY - 2022/10/10

Y1 - 2022/10/10

N2 - Due to the rapidly degradative mechanical performance of selective laser melted (SLM) Al–12Si at elevated temperatures, an Al–12Si–Ti alloy was synthesized by SLM processing with a powder mixture consisting of Al–12Si and 1 wt% of Ti nanoparticles to improve its thermal stability at mid-temperatures (573 K). The results demonstrate that the addition of Ti nanoparticles (i) enlarges the parameter window of SLM processing (power inputs of 200–350 W and scanning speeds of 600–1600 mm/s), (ii) stimulates a columnar to equiaxed transition and refinement of grains (average grain size decreases from 9.0 μm to 1.5 μm), (iii) forms Al3Ti phase improving the thermal stability of Al–Si eutectic cell structure, and (iv) partially suppresses the precipitation of Si phase and coarsening of cell structure at elevated temperatures. These features lead to an improved yield strength of SLM Al–12Si–Ti compared with SLM Al–12Si. Specifically, SLM Al–12Si–Ti annealed at 573 K possesses a higher yield strength (297 ± 10 MPa) than SLM Al–12Si (207 ± 9 MPa) annealed at the same conditions. This study will pave the way for the design and synthesis of SLM Al alloys with improved structural and mechanical stability by minor alloying via nanoparticle addition.

AB - Due to the rapidly degradative mechanical performance of selective laser melted (SLM) Al–12Si at elevated temperatures, an Al–12Si–Ti alloy was synthesized by SLM processing with a powder mixture consisting of Al–12Si and 1 wt% of Ti nanoparticles to improve its thermal stability at mid-temperatures (573 K). The results demonstrate that the addition of Ti nanoparticles (i) enlarges the parameter window of SLM processing (power inputs of 200–350 W and scanning speeds of 600–1600 mm/s), (ii) stimulates a columnar to equiaxed transition and refinement of grains (average grain size decreases from 9.0 μm to 1.5 μm), (iii) forms Al3Ti phase improving the thermal stability of Al–Si eutectic cell structure, and (iv) partially suppresses the precipitation of Si phase and coarsening of cell structure at elevated temperatures. These features lead to an improved yield strength of SLM Al–12Si–Ti compared with SLM Al–12Si. Specifically, SLM Al–12Si–Ti annealed at 573 K possesses a higher yield strength (297 ± 10 MPa) than SLM Al–12Si (207 ± 9 MPa) annealed at the same conditions. This study will pave the way for the design and synthesis of SLM Al alloys with improved structural and mechanical stability by minor alloying via nanoparticle addition.

KW - Additive manufacturing

KW - Al alloys

KW - Heat treatment

KW - Mechanical properties

KW - Microstructure

UR - http://www.scopus.com/inward/record.url?scp=85137268726&partnerID=8YFLogxK

U2 - 10.1016/j.msea.2022.143833

DO - 10.1016/j.msea.2022.143833

M3 - Article

AN - SCOPUS:85137268726

VL - 855.2022

JO - Materials Science and Engineering A

JF - Materials Science and Engineering A

SN - 0921-5093

IS - 10 October

M1 - 143833

ER -