Page 54 - ESAM-1-2

Engineering Science in
Additive Manufacturing Multi-material additive manufacturing of metals

exhibited good metallurgical bonding, though dendritic such as P21/SS316L and 17-4PH/SS316L, both of
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cracks were observed, attributed to CTE mismatch. The which employ ferrous alloys as base materials, distinct
more significant reduction in flexural strength observed by deformation behaviors were observed under compression
Chen et al. compared to Chen et al. can be attributed to loading. Post-failure analysis revealed that SS316L
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a wider transition zone, which compromises mechanical specimens exhibited axisymmetric plastic deformation,
homogeneity across the interface. Finally, in AlSi10Mg/ indicative of uniform plastic flow. In contrast, P21/SS316L
C18400 MMAM structures, the orientation of the base deformed laterally due to differences in the compressive
material significantly influenced flexural performance. YS between the constituent materials. These experimental
When Al served as the substrate, both flexural strength findings were validated by an FEA study, which accurately
and strain were higher compared to configurations where predicted the observed deformation patterns. Further
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Cu was the base material. This outcome is linked to the details regarding the FEA methodology and results are
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higher porosity and lower mechanical integrity of the discussed in Section 5. The observed deformation behavior
Cu-rich region, emphasizing that most of the load-bearing can be further explained by considering the underlying
capacity is retained by the Al side. In both cases, porosity plastic deformation mechanisms. Both 17-4PH and P21
formation at the interface, attributed to mismatch thermal possess a body-centered cubic (BCC) structure, which
properties, resulted in reduced flexural strength. impedes dislocation motion, while SS316L has a face-
centered cubic (FCC) structure that facilitates dislocation
4.4. Compression strength slip. This mismatch in crystal structure contributes to
Among the available MMAM empirical studies, the axisymmetric barreling plastic deformation observed
compression testing remains relatively underexplored, (Figure 13B and C). Furthermore, residual thermal stresses
with only a limited number of investigations focusing on arising from mismatched CTE between the materials may
this mechanical property. Notably, in MMAM structures also contribute to strain-hardening effects. 147

A

B

Figure 12. Flexural stress–strain response of bimetallic structures fabricated through mixed-material laser powder bed fusion. (A) C300MS/AISI304 and
C300MS/AISI1045 carbon steel; and (B) MS1/T2. The graphs illustrate the flexural strength at the interface of the bimetallic structures and the role of
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metallurgical bonding under flexural loading.
Volume 1 Issue 2 (2025) 22 doi: 10.36922/ESAM025180010