Design and Manufacture of Bionic Porous Titanium Alloy Spinal Implant Based on Selective Laser Melting (SLM)

In order to meet the clinical requirements of spine surgery, this paper proposed the exploratory research of computer-aided design and selective laser melting (SLM) fabrication of a bionic porous titanium spine implant. The structural design of the spinal implant is based on CT scanning data to ensure correct matching, and the mechanical properties of the implant are verified by simulation analysis and laser selective melting experiment. The surface roughness of the spinal implant manufactured by SLM without post-processing is Ra 15 mu m, and the implant is precisely jointed with the photosensitive resin model of the upper and lower spine. The surface micro-hardness of the implant is HV 373, tensile strength sigma(b) = 1238.7 MPa, yield strength sigma(0)(.2) = 1043.9 MPa, the elongation is 6.43%, and the compressive strength of porous structure under 84.60% porosity is 184.09 MPa, which can meet the requirements of the reconstruction of stable spines. Compared with the traditional implant and intervertebral fusion cage, the bionic porous spinal implant has the advantages of accurate fit, porous bionic structure and recovery of patients, and the ion release experiment proved that implants manufactured by SLM are more suitable for clinical application after certain treatments. The elastic modulus of the sample is improved after heat treatment, mainly because the microstructure of the sample changes from alpha' phase to alpha + beta dual-phase after heat treatment. In addition, the design of high-quality bionic porous spinal implants still needs to be optimized for the actual needs of doctors.