Study On The Preparation Processing Of Ti6Al4V Three-dimensional Lattice Structure And Its Mechanical Behavior

There is little research on three dimensional lattice sandwich structures prepared by the novel Super Plastic Forming/Diffusion Bonding (SPF/DB). In this thesis, the effect of different geometric parameters on deformation resistance of as-prepared Ti6A14V lattice structure was studied. Exploring structural failure mechanisms and providing support to strengthen the structure through failure analysis.Compression tests and shear tests were conducted for several lattice structures with different types, layers and cell size. The failure mechanism was analyzed by analytical method and finite element analysis.The results showed that for small cell monolayer lattice structures, the pyramid type has optimum compressive modulus and the tetrahedral owns the highest compressive strength, which is about70.83%higher than that of the pyramid. Moreover, cell size is30mm monolayer lattice structures, the pyramid shows the best shear modulus, while the tetrahedral with equivalent relative density owns the highest shear strength, about8.21%higher than that of the pyramid. As to the absorbed energy in compressive tests, the X-type ranks the first when the true strain was about0.4.In compression tests, the changes of as-produced lattice structure include several stages:elastic deformation, buckling, structural strengthens, the second softening and densification. Similarly, there are resist deformation, winding and complete destroy exist in the shear test. In this thesis, the structural failure mainly resulted from ribs buckling, accompanied with broken ribs and nodes destruction.