Microstructure, Anisotropic Mechanical Properties and Very High Cycle Fatigue Behavior of Ti6Al4V Produced by Selective Electron Beam Melting

摘要

In this paper, surface roughness, microstructure, mechanical properties, and very high cycle fatigue behavior of Ti6Al4V fabricated by selective electron beam melting were studied. Results show that the mechanical properties in xoz direction (yield strength: 891 +/- 14 MPa, ultimate tensile strength: 987 +/- 8 MPa, elongation: 15.7 +/- 1.9%) are better than that in xoy direction (yield strength: 869 +/- 11 MPa, ultimate tensile strength: 955 +/- 7 MPa, elongation: 9.8 +/- 2.3%) due to the presence of continuous columnar prior-beta grain boundary (alpha layer) and the strong < 0001 & rang; texture along the building direction. The very high cycle fatigue (10(5)-10(9) cycles) experiments show that when the fatigue life exceeds 10(7) cycles, the sample will still undergo fatigue fracture. The S-N curve is a bilinear relation, which is caused by the crack initiation position converted from the surface to the interior. Graphic

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