Characterization and fatigue behavior of Ti-6Al-4V foams

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2012
Aşık, Emin Erkan
Porous Ti-6Al-4V alloys are widely used in the biomedical applications for hard tissue implantation due to its biocompatibility and elastic modulus being close to that of bone. In this study, porous Ti-6Al-4V alloys were produced with a powder metallurgical process, space holder technique, where magnesium powders were utilized in order to generate porosities in the range of 50 to 70 vol. %. In the productions of Ti-6Al-4V foams, first, the spherical Ti-6Al-4V powders with an average size of 55 μm were mixed with spherical magnesium powders sieved to an average size of 375 μm, and then the mixtures were compacted with a hydraulic press under 500 MPa pressure by using a double-ended steel die and finaly, the green compacts were sintered at 1200˚C for 2 hours under high purity argon gas atmosphere. Scanning electron microscope investigation of produced foams has shown that the foams consist of spherical, interconnected macropores and irregular shaped micropores. Monotonic compression tests conducted on processed foams under quasi-static test conditions exhibited yield strengths varying between 69 to 167 MPa and elastic moduli between 4 to 12 GPa. Processed foams were also dynamically tested under compression - compression fatigue with a stress ratio of 0.1. Foams with different pore contents exhibited similar fatigue response when maximum applied stress was normalized with respect to the average yield strength of the corresponding foam. It was found that foams were fatigue immune with a practical limit of 106 cycles under a maximum applied stress of 0.75*(σmax/σyield).

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Citation Formats
E. E. Aşık, “Characterization and fatigue behavior of Ti-6Al-4V foams,” M.S. - Master of Science, Middle East Technical University, 2012.