29 research outputs found
Effect of SLM parameters on the structure and properties of CP-Ti
Selective laser melting (SLM) is an additive manufacturing technique, which allows varying the relative porosity at the micro and macro levels. In this study, the microstructure, including the porous structure, of cp-Ti Grade 1 ELI produced by SLM and the effect of the scanning parameters on mechanical properties are studied. The mechanical properties are analyzed in terms of ISO 5832-2 for metal implants for surgery. The cp-Ti samples processed by SLM are characterized by increased strength due to the low porosity condition and the acicular martensitic structure. The ductility data scattering is explained by the stratified distribution of porosity in the metal after SLM. © 2018 Author(s)
On Traces of d-stresses in the Skeletons of Lower Dimensions of Piecewise-linear d-manifolds
We show how a d-stress on a piecewise-linear realization of an oriented (non-simplicial, in general) d-manifold in R d naturally induces stresses of lower dimensions on this manifold, and discuss implications of this construction to the analysis of self-stresses in spatial frameworks. The mappings we construct are not linear, but polynomial. In the 1860–70s J. C. Maxwell described an interesting relationship between self-stresses in planar frameworks and vertical projections of polyhedral 2-surfaces. We offer a spatial analog of Maxwell’s correspondence based on our polynomial mappings. By applying our main result we derive a class of three-dimensional spider webs similar to the two-dimensional spider webs described by Maxwell. We also conjecture an important property of our mappings that is Author: based on the lower bound theorem (g2(d +1) = dim Stress2 ≥ 0) for d-pseudomanifolds generically realized in R d+1 [12]