The demand for advanced materials has driven innovation in titanium alloy design, particularly in the aerospace, automotive, and biomedical sectors. Additive manufacturing (AM) enables the construction of multi-material structures, offering potential improvements in mechanical properties such as wear resistance and high-temperature capabilities, thus extending the service life of components such as Ti6Al4V. Directed energy deposition (DED)-based metal AM was used to manufacture radial multi-material structures with a Ti6Al4V (Ti64) core and a Ti6Al4V-5 wt.% B4C composite outer layer. X-ray diffraction analysis and microstructural observation suggest that distinct B4C particles are strongly attached to the Ti6Al4V matrix. The addition of B4C increased the average hardness from 313 HV for Ti6Al4V to 538 HV for the composites. The addition of 5 wt.% B4C in Ti6Al4V increased the average compressive yield strength (YS) to 1440 MPa from 972 MPa for the control Ti6Al4V, i.e., >48% increase without any significant change in the elastic modulus. The radial multi-material structures did not exhibit any changes in the compressive modulus compared to Ti6Al4V but displayed an increase in the average compressive YS to 1422 MPa, i.e., >45% higher compared to Ti6Al4V. Microstructural characterization revealed a smooth transition from the pure Ti6Al4V at the core to the Ti64-B4C composite outer layer. No interfacial failure was observed during compressive deformation, indicating a strong metallurgical bonding during multi-material radial composite processing. Our results demonstrated that a significant improvement in mechanical properties can be achieved in one AM build operation through designing innovative multi-material structures using DED-based AM.
In this study, we measured the tensile, compression, and fatigue behavior of additively manufactured Ti3Al2V as a function of build orientation. Ti3Al2V alloy was prepared by mixing commercially pure titanium and Ti6Al4V in 1:1 wt. ratio. Laser powder bed fusion-based additive manufacturing technique was used to fabricate the samples. Tensile tests resulted in an ultimate strength of 989 ± 8 MPa for Ti3Al2V. Ti6Al4V 90° orientation samples showed a compressive yield strength of 1178 ± 33 MPa and that for Ti3Al2V 90° orientation samples were 968 ± 24 MPa. By varying the build orientation to account for anisotropy, Ti32 45° and Ti32 0° samples displayed almost similar compressive yield strength values of 1071 ± 16 and 1051 ± 18 MPa, respectively, which were higher than that of Ti32 90° sample. Fatigue loading revealed an endurance limit (10 million cycles) of 250 MPa for Ti6Al4V and of 219 MPa for Ti3Al2V built at 90° orientation. The effect of the build orientation was significant under fatigue loading; Ti3Al2V built at 45° and 0° orientations displayed endurance limits of 387.5 MPa and 512 MPa, respectively; more than two-fold increment in endurance limit was observed. In conclusion, the superior attributes of Ti3Al2V alloy over Ti6Al4V alloy, as demonstrated in this study, justify its potential in load-bearing applications, particularly for use in orthopedic devices.
more » « less- Award ID(s):
- 1934230
- NSF-PAR ID:
- 10536680
- Publisher / Repository:
- ACCScience Publishing
- Date Published:
- Journal Name:
- Materials Science in Additive Manufacturing
- Volume:
- 2
- Issue:
- 3
- ISSN:
- 2810-9635
- Page Range / eLocation ID:
- 1705
- Subject(s) / Keyword(s):
- Additive manufacturing Titanium alloys Alloy design Load-beating implants Fatigue behavior.
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.36922/msam.1705
