Selective laser melting (SLM) technology plays an important role in the preparation of porous titanium (Ti) implants with complex structures and precise sizes. Unfortunately, the processing characteristics of this technology, which include rapid melting and solidification, lead to products with high residual stress. Herein, an in situ method was developed to restrain the residual stress and improve the mechanical strength of porous Ti alloys during laser additive manufacturing. In brief, porous Ti6Al4V was prepared by an SLM three-dimensional (3D) printer equipped with a double laser system that could rescan each layer immediately after solidification of the molten powder, thus reducing the temperature gradient and avoiding rapid melting and cooling. Results indicated that double scanning can provide stronger bonding conditions for the honeycomb structure and improve the yield strength and elastic modulus of the alloy. Rescanning with an energy density of 75% resulted in 33.5%–38.0% reductions in residual stress. The porosities of double-scanned specimens were 2%–4% lower than those of single-scanned specimens, and the differences noted increased with increasing sheet thickness. The rescanning laser power should be reduced during the preparation of porous Ti with thick cell walls to ensure dimensional accuracy.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Tax calculation will be finalised during checkout.
D.K. Pattanayak, A. Fukuda, T. Matsushita, M. Takemoto, S. Fujibayashi, K. Sasaki, N. Nishida, T. Nakamura, and T. Kokubo, Bioactive Ti metal analogous to human cancellous bone: Fabrication by selective laser melting and chemical treatments, Acta Biomater., 7(2011), No. 3, p. 1398.
D. Banerjee and J.C. Williams, Perspectives on titanium science and technology, Acta Mater., 61(2013), No. 3, p. 844.
S. Zherebtsov, M. Murzinova, G. Salishchev, and S.L. Semiatin, Spheroidization of the lamellar microstructure in Ti-6Al-4V alloy during warm deformation and annealing, Acta Mater., 59(2011), No. 10, p. 4138.
P. Song, C. Hu, X. Pei, J.X. Sun, H. Sun, L.N. Wu, Q. Jiang, H.Y. Fan, B.C. Yang, C.C. Zhou, Y.J. Fan, and X.D. Zhang, Dual modulation of crystallinity and macro-/microstructures of 3D printed porous titanium implants to enhance stability and osseointegration, J. Mater. Chem. B, 7(2019), No. 17, p. 2865.
Ö. Bayrak, H.G. Asl, and A. Ak, Protein adsorption, cell viability and corrosion properties of Ti6Al4V alloy treated by plasma oxidation and anodic oxidation, Int. J. Miner. Metall. Mater., 27(2020), No. 9, p. 1269.
X. Pei, B.Q. Zhang, Y.J. Fan, X.D. Zhu, Y. Sun, Q.G. Wang, X.D. Zhang, and C.C. Zhou, Bionic mechanical design of titanium bone tissue implants and 3D printing manufacture, Mater. Lett., 208(2017), p. 133.
L. Zhao, X. Pei, L.H. Jiang, C. Hu, J.X. Sun, F. Xing, C.C. Zhou, Y.J. Fan, and X.D. Zhang, Bionic design and 3D printing of porous titanium alloy scaffolds for bone tissue repair, Composites Part B, 162(2019), p. 154.
B.Q. Zhang, X. Pei, C.C. Zhou, Y.J. Fan, Q. Jiang, A. Ronca, U. D’Amora, Y. Chen, H.Y. Li, Y. Sun, and X.D. Zhang, The biomimetic design and 3D printing of customized mechanical properties porous Ti6Al4V scaffold for load-bearing bone reconstruction, Mater. Des., 152(2018), p. 30.
M.E. Davis, Ordered porous materials for emerging applications, Nature, 417(2002), No. 6891, p. 813.
B. Levine, A new era in porous metals: Applications in orthopaedics, Adv. Eng. Mater., 10(2008), No. 9, p. 788.
D.C. Dunand, Processing of titanium foams, Adv. Eng. Mater., 6(2004), No. 6, p. 369.
V.K. Balla, S. Bodhak, S. Bose, and A. Bandyopadhyay, Porous tantalum structures for bone implants: Fabrication, mechanical and in vitro biological properties, Acta Biomater., 6(2010), No. 8, p. 3349.
J.P. Kruth, G. Levy, F. Klocke, and T.H.C. Childs, Consolidation phenomena in laser and powder-bed based layered manufacturing, CIRP Ann., 56(2007), No. 2, p. 730.
H.Y. Chen, D.D. Gu, Q. Ge, X.Y. Shi, H.M Zhang, R. Wang, H. Zhang, and K. Kosiba, Role of laser scan strategies in defect control, microstructural evolution and mechanical properties of steel matrix composites prepared by laser additive manufacturing, Int. J. Miner. Metall. Mater., (2020). DOI: https://doi.org/10.1007/s12613-020-2133-x
X. Li, C.T. Wang, W.G. Zhang, and Y.C. Li, Fabrication and characterization of porous Ti6Al4V parts for biomedical applications using electron beam melting process, Mater. Lett., 63(2009), No. 3–4, p. 403.
F.A. Shah, A. Snis, A. Matic, P. Thomsen, and A. Palmquist, 3D printed Ti6Al4V implant surface promotes bone maturation and retains a higher density of less aged osteocytes at the bone-implant interface, Acta Biomater., 30(2016), p. 357.
M. Strantza, R.K. Ganeriwala, B. Clausen, T.Q. Phan, L.E. Levine, D. Pagan, W.E. King, N.E. Hodge, and D.W. Brown, Coupled experimental and computational study of residual stresses in additively manufactured Ti-6Al-4V components, Mater. Lett., 231(2018), p. 221.
J.D. Roehling, W.L. Smith, T.T. Roehling, B. Vrancken, G.M. Guss, J.T. McKeown, M.R. Hill, and M.J. Matthews, Reducing residual stress by selective large-area diode surface heating during laser powder bed fusion additive manufacturing, Addit. Manuf., 28(2019), p. 228.
W.H. Yu, S.L. Sing, C.K. Chua, and X.L Tian, Influence of re-melting on surface roughness and porosity of AlSi10Mg parts fabricated by selective laser melting, J. Alloys Compd., 792(2019), p. 574.
J.L. Cabezas-Villa, J. Lemus-Ruiz, D. Bouvard, O. Jiménez, H.J. Vergara-Hernández, and L. Olmos, Sintering study of Ti6Al4V powders with different particle sizes and their mechanical properties, Int. J. Miner. Metall. Mater., 25(2018), No. 12, p. 1389.
R. Singh, P.D. Lee, R.J. Dashwood, and T.C. Lindley, Titanium foams for biomedical applications: A review, Mater. Technol., 25(2010), No. 3–4, p. 127.
B.V. Hooreweder, Y. Apers, K. Lietaert, and J.P. Kruth, Improving the fatigue performance of porous metallic biomaterials produced by Selective Laser Melting, Acta Biomater., 47(2017), p. 193.
W. Long, S. Zhang, Y.L. Liang, and M.G. Ou, Influence of multi-stage heat treatment on the microstructure and mechanical properties of TC21 titanium alloy, Int. J. Miner. Metall. Mater., (2020). DOI: https://doi.org/10.1007/s12613-020-1996-1
R.K. Gupta, V.A. Kumar, C. Mathew, and G.S. Rao, Strain hardening of Titanium alloy Ti6Al4V sheets with prior heat treatment and cold working, Mater. Sci. Eng. A, 662(2016), p. 537.
D. Buchbinder, W. Meiners, N. Pirch, K. Wissenbach, and J. Schrage, Investigation on reducing distortion by preheating during manufacture of aluminum components using selective laser melting, J. Laser Appl., 26(2014), No. 1, p. 12004.
G. Vastola, G. Zhang, Q.X. Pei, and Y.W. Zhang, Active control of microstructure in powder-bed fusion additive manufacturing of Ti6Al4V, Adv. Eng. Mater., 19(2017), No. 12, p. 1700333.
X.C Yan, Q. Li, S. Yin, Z.Y. Chen, R. Jenkins, C.Y. Chen, J. Wang, W.Y. Ma, R. Bolot, R. Lupoi, Z.M. Ren, H.L. Liao, and M. Liu, Mechanical and in vitro study of an isotropic Ti6Al4V lattice structure fabricated using selective laser melting, J. Alloys Compd., 782(2019), p. 209.
V. Weißmann, R. Bader, H. Hansmann, and N. Laufer, Influence of the structural orientation on the mechanical properties of selective laser melted Ti6Al4V open-porous scaffolds, Mater. Des., 95(2016), p. 188.
S. Suresh and A.E. Giannakopoulos, A new method for estimating residual stresses by instrumented sharp indentation, Acta Mater., 46(1998), No. 16, p. 5755.
F.Q. Gao and A.A. Sonin, Precise deposition of molten micro-drops: The physics of digital microfabrication, Proc. R. Soc. London A, 444(1994), No. 1922, p. 533.
X.Q. Ni, D.C. Kong, Y. Wen, L. Zhang, W.H. Wu, B.B. He, L. Lu, and D.X. Zhu, Anisotropy in mechanical properties and corrosion resistance of 316L stainless steel fabricated by selective laser melting, Int. J. Miner. Metall. Mater., 26(2019), No. 3, p. 319.
V. Seyda, N. Kaufmann, and C. Emmelmann, Investigation of aging processes of Ti-6Al-4V powder material in laser melting, Phys. Procedia, 39(2012), p. 425.
O.A. Quintana, J. Alvarez, R. Mcmillan, W.D. Tong, and C. Tomonto, Effects of reusing Ti-6Al-4V powder in a selective laser melting additive system operated in an industrial setting, JOM, 70(2018), No. 9, p. 1863.
K.C. Nune, S.J. Li, and R.D.K. Misra, Advancements in three-dimensional titanium alloy mesh scaffolds fabricated by electron beam melting for biomedical devices: Mechanical and biological aspects, Sci. China Mater., 61(2018), No. 4, p. 455.
G. Bevill and T.M. Keaveny, Trabecular bone strength predictions using finite element analysis of micro-scale images at limited spatial resolution, Bone, 44(2009), No. 4, p. 579.
E.F. Morgan, H.H. Bayraktar, and T.M. Keaveny, Trabecular bone modulus-density relationships depend on anatomic site, J. Biomech., 36(2003), No. 7, p. 897.
X.D. Wang, J.S. Nyman, X.L. Dong, H.J. Leng, and M. Reyes, Fundamental Biomechanics in Bone Tissue Engineering, Morgan & Claypool Publishers, Williston, 2010, p. 79.
M.F. Ashby, A. Evans, N.A. Fleck, L.J. Gibson, J.W. Hutchinson, and H.N.G. Wadley, Metal Foams: A Design Guide, Butterworth-Heinemann, Burlington, 2000, p. 144.
T. Lei, Titanium and Titanium Alloy, Metallurgical Industry Press, Beijing, 2018, p. 238.
M. Hakamada, Y. Asao, T. Kuromura, Y.Q. Chen, H. Kusuda, and M. Mabuchi, Density dependence of the compressive properties of porous copper over a wide density range, Acta Mater., 55(2007), No. 7, p. 2291.
Y. Yamada, C.E. Wen, K. Shimojima, H. Hosokawa, Y. Chino, and M. Mabuchi, Compressive deformation characteristics of open-cell Mg alloys with controlled cell structure, Mater. Trans., 43(2002), No. 6, p. 1298.
F.S.L. Bobbert, K. Lietaert, A.A. Eftekhari, B. Pouran, S.M. Ahmadi, H. Weinans, and A.A. Zadpoor, Additively manufactured metallic porous biomaterials based on minimal surfaces: A unique combination of topological, mechanical, and mass transport properties, Acta Biomater., 53(2017), p. 572.
J.F. Wang, J.T. Yuan, Z.H. Wang, B. Zhang, and J.X. Liu, Deformation and residual stress of TC4 titanium alloy thin-wall parts by selective laser melting, Laser Technol., 43(2019), No. 3, p. 411.
H. Ali, H. Ghadbeigi, and K. Mumtaz, Effect of scanning strategies on residual stress and mechanical properties of selective laser melted Ti6Al4V, Mater. Sci. Eng. A, 712(2018), p. 175.
This work was financially supported by the National Natural Science Foundation of China (Nos. 52004026 and 51725401) and the Fundamental Research Funds for the Central Universities, China (No. FRF-TP-18-003C2). The helpful comments, suggestions, and encouragement from the editors and anonymous reviewers are gratefully acknowledged.
About this article
Cite this article
Luo, Yw., Wang, My., Tu, Jg. et al. Reduction of residual stress in porous Ti6Al4V by in situ double scanning during laser additive manufacturing. Int J Miner Metall Mater (2021). https://doi.org/10.1007/s12613-020-2212-z
- porous titanium
- selective laser melting
- additive manufacturing
- residual stress
- mechanical properties