Analysis of fatigue resistance of titanium alloy produced by Electron Beam Powder Bed Fusion
Abstract
Additive manufacturing of titanium alloys by powder bed fusion with electron beam (PBF-EB) offers new possibilities for the production of biomedical implants, hip joint endoprosthetics, fracture fixation plates, elements used in the spine, screws and wires. This alloy was developed in the 1980s with the intention of replacing Ti-6Al-4V in medical applications, reducing the risk of cytotoxicity while maintaining high strength parameters. Ti-6Al-7Nb has been shown to offer comparable mechanical characteristics to Ti-6Al-4V (e.g., tensile strength of 900–1000 MPa) with significantly higher biocompatibility in biological environments [5]. However the fatigue behavior of Ti-6Al-7Nb fabricated by this technique has not been investigated. This study addresses this research gap by evaluating the high cycle fatigue (HCF) performance of Ti-6Al-7Nb samples manufactured using PBF-EB. Fatigue tests were conducted under cyclic loading conditions (R=-1) up to 107 cycles, using specimens designed according to ASTM E466-21 standard. Two build orientations: parallel and perpendicular to the loading direction were considered, and the effect of hot isostatic pressing (HIP) treatment was systematically analyzed.
