Effect of designed pore size on electrochemical, wear, and tribocorrosion behavior of additively manufactured Ti-6Al-4V lattice structures

Abstract

The advent of additive manufacturing has been a disruptive technology in various fields, including medicine. One of the main causes of orthopedic implant failure is the mismatch between the implant material and the bone, causing bone resorption and aseptic loosening. In this regard, the use of additively manufactured lattice structures as orthopedic implant material has several advantages, such as producing a material with an adequate stiffness match with bone. Nevertheless, its behavior in service is not fully understood: the human body is a complex environment, and an orthopedic implant material is subjected to corrosion, wear, and tribocorrosion. In this work, Ti-6Al-4V solid and lattice structured samples were designed with pore sizes of 500, 700, and 900 µm and produced by PBF-EB. Microstructural and geometrical characterization was made on produced samples. The effect of pore sizes was analyzed under corrosion, wear, and tribocorrosion conditions, and compared with solid bulk samples. During corrosion tests, porous samples presented pitting attacks at high potentials, as the solid samples did not. The porous and solid samples presented similar behaviors under wear and tribocorrosion, with abrasive and adhesive wear as the predominant mechanism, and no statistical difference in the specific wear rates was found.