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  • Tailoring compositionally graded interface of 316L stainless steel to Al12Si aluminum alloy bimetallic structures via Additive Manufacturing
Title: Tailoring compositionally graded interface of 316L stainless steel to Al12Si aluminum alloy bimetallic structures via Additive Manufacturing
316L stainless steel (SS) to Al12Si aluminum alloy structures were processed, tailoring the compositionally graded interface on a SS 316 substrate using a directed energy deposition (DED)-based additive manufacturing (AM) process. Applying such a compositionally graded transition on bimetallic materials, especially joining two dissimilar metals, could avoid the mechanical property mismatch. This study's objective was to understand the processing parameters that influence the properties of AM processed SS 316L to Al12Si bimetallic structures. Two different approaches fabricated these bimetallic structures. The results showed no visible defects on the as-fabricated samples using 4 layers of Al-rich mixed composition as the transition section. The microstructural characterization showed a unique morphology in each section. Both cooling rate and compositional variations caused microstructural variation. FeAl, Fe2Al5, and FeAl3 intermetallic phases were formed at the compositionally graded transition section. After stress relief heat-treatment of SS 316L/Al12Si bimetallic samples, diffused intermetallic phases were seen at the compositionally graded transition. At the interface, as processed, bimetallic structures had a microhardness value of 834.2 ± 107.1 HV0.1, which is a result of the FeAl3 phase at the compositionally graded transition area. After heat-treatment, the microhardness value reduced to 578.7 ± 154.1 HV0.1 due to more Fe dominated FexAly phase formation. The compression test results showed that the non-HT and HT SS 316L/Al12Si bimetallic structures had a similar maximum compressive strength of 299.4 ± 22.1 MPa and 270.1 ± 27.1 MPa, respectively.  more » « less
Award ID(s):
1934230
PAR ID:
10282685
Author(s) / Creator(s):
;
Date Published:
Journal Name:
ACS applied materials interfaces
Volume:
13
Issue:
7
ISSN:
1944-8252
Page Range / eLocation ID:
9174–9185
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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