TiNi Alloy Lattice Structures with Negative Poisson’s Ratio: Computer Simulation and Experimental Results

Abstract

One of the issues that modern implants face is their high stiffness, coupled with a positive Poisson’s ratio along the implant. This creates certain problems with bone inflammation and implant detachment. A possible solution to these problems is TiNi alloy lattice structure implants with low stiffness and negative Poisson’s ratio. This paper presents the results of simulation, fabrication by the SLM technique, and study of lattice structures with negative Poisson’s ratio, which can help to solve said problems. The studies involve the determination of mechanical characteristics, Poisson’s ratio, transformation temperatures, and the potential for a superelasticity effect of the lattice structure. The characteristics obtained at initial simulation were partially confirmed in the course of the works. Moreover, the possibility of fabricating TiNi alloy lattice structures with negative Poisson’s ratio (about −0.00323) and low Young’s modulus values (0.818 GPa) was confirmed by the SLM technique.

Keywords

• lattice structure
• negative poisson’s ratio
• nitinol
• shape memory alloy
• superelasticity