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Producing hip implants of titanium alloys by additive manufacturing

(A) (B)

(C) (D)
Figure 6. Microstructures of the Ti-6Al-4V alloy produced by SLM before (A, B) and after annealing at 800°С (C, D): α-phase (gray
lamellae), β-phase (black lines).

relieving. After annealing (Figures 6C and D), a par- Powder Bed Fusion) and ISO 5832-3 (Implants for
tial decomposition of the α′-phase into the α- and β-ph- surgery – Metallic materials – Part 3: Wrought titanium
ases occurred with enlargement of the acicular α′- 6-aluminium 4-vanadium alloy).
phase and formation of the β-phase on grain bounda-
ries and needles of the martensitic phase. Heat treat- 4. Conclusion
ment of the produced material leads to increased elon- The capabilities of additive manufacturing technolo-
gation at break with a slight decrease in tensile stre- gies were shown to successfully produce a custom-
ngth. Different annealing parameters used in this work made component of a hip implant endoprosthesis from
did not noticeably affect the mechanical properties of Ti-6Al-4V alloy.
the material. Compared to the properties of the Ti- Since the configuration of the implant matches the
6Al-4V alloy obtained by EBM, SLM materials shows anatomical features of the patient, the risk of early
higher tensile strength, but significantly lower elonga- instability development is decreased, the surgery time
tion at break. This might be due to higher cooling rates is reduced together with blood loss and risk of infectious
during the SLM process which result in finer micro- complication development. The possibility of creating
structures and higher residual stresses of the SLM- a texturized surface of the implant by SLM technology
material. The overall mechanical properties (Table 1) allows to potentially improve the osseointegration
of the produced material meet the requirements of process by creating areas with high specific surface.
ASTM F2924–14 (Standard Specification for Additive Microstructures of the produced material after an-
Manufacturing Titanium-6 Aluminum-4 Vanadium with nealing consist of partially decomposed martensitic

82 International Journal of Bioprinting (2016)–Volume 2, Issue 2