Structure and properties of 3D printed porous tantalum

Due to the high density of metallic tantalum, when used as a medical implant material, it is usually presented in the form of a porous structure, which not only gives full play to the excellent biocompatibility of metallic tantalum, but at the same time provides a natural channel for tissue growth with the rich pore structure of porous materials. Therefore, another important area of research related to 3D printing porous tantalum is porous tantalum. However, since the development of 3D printed metals to date, relatively little research has been reported on 3D printed porous tantalum materials. The University of Leuven, Belgium, realized the preparation of porous tantalum materials with uniform pore structure by using spherical metallic tantalum powder as raw material in 2015, and comprehensively evaluated their mechanical properties.

The test results of compressive stress-strain show that the yield strength is 12.7 MPa s 0.6 MPa, the plateau stress is 21.8 MPa s 0.9 MPa, the compressive elastic modulus is 1.22 GPa s 0.07 GPa, and the plateau region of the curves is smooth and non-serrated, which indicates that the porous tantalum material prepared by SLM has excellent plasticity, and the modulus is perfectly matched with that of human cancellous bone. In addition, the compressive fatigue limit of porous tantalum is 7.35 MPa (10⁶ times), which shows a high resistance to cyclic loading.
Currently, tantalum and porous tantalum are considered to be the best biocompatible orthopedic implant materials, and China's application of 3D printed porous tantalum is at the forefront of the world.In 2016, under the support of the Key Research and Development Program of the Ministry of Science and Technology, Northwest Nonferrous Metals Research Institute (NWNMRI), together with the Southwest Hospital, accomplished the world's first case of personalized powdered e-beam 3D printed porous tantalum implant body preparation and achieved clinical application. At present, Northwest Nonferrous Metals Research Institute and its subordinate Xi'an Sailon Metal Materials Co. have realized the coverage of the whole industrial chain of powder raw materials, electron beam forming equipment and process of medical porous tantalum implants.