Compression Behavior of Diamond Lattice Structure and Its Hall–Petch Relationship

As the additive manufacturing (AM) technology improves, in particular the selective laser melting (SLM) advance, lattice structures made of Ti6Al4V become a new material and are applied in aerospace and medical field increasingly. It is essential to investigate the compression behavior and size effect in diamond lattice structure. Herein, a new analytical model based on elastic strain energy is presented for predicting the compressive properties of diamond lattice structure. The effective diameter D_e is put forward to improve the accuracy of prediction. In addition, the effects of unit cell size on the mechanical properties and energy absorption are investigated. The results show that first peak stress and elastic modulus can be predicted well by the analytical models. Through quantitative analysis, the relationships between mechanical properties and unit cell size in different relative density can be concluded as Hall–Petch relationships. In addition, the energy absorption increases with relative density and changes with the unit cell size.