ABSTRACT
Over the past few years, Ti–Nb–Ta–Zr (TNTZ) titanium alloy is considered a promising candidate as an orthopedic implant, which exhibits comparable modulus and good mechanical and fatigue strengths. While preferring biomedical implants, the “stress shielding effect” is a major issue developed due to the large difference in elastic modulus between bone and the implanted material. This effect eventually leads to premature failure of the implant material. To cope up with these issues, lattice-structured materials would be a good choice. A lattice-structured material is fabricated to obtain reduced modulus close to that of human bone for minimizing the stress shielding effect. To print a layered lattice-structured material, a selective laser melting (SLM) process is preferred which enables the fabrication of complex 3D lattice-structured titanium alloys directly from a model generated via computer-aided design (CAD) software. In the present work, the extended finite element method (XFEM) is utilized to numerically investigate the performance against a ductile fracture from crack nucleation until fracture during tensile loading. Further, elasto-plastic crack growth simulations are accomplished by XFEM through enriching the standard approximation for an SLM-processed TNTZ alloy. The simulated results are found to be in good agreement with the experimentally obtained fracture characteristics of a TNTZ alloy.
