The mechanical characteristics of a monolithic (non-porous) crystalline or amorphous material are described by a well-defined set of quantities. It is possible to change the mechanical properties by introducing porosity into this material; as a rule, the strength values decrease with the introduction of porosity. Thus, porosity can be considered an additional degree of freedom that can be used to influence the hardness, strength and plasticity of the material. In the present work, using porous crystalline NiTi as an example, it is shown that the mechanical characteristics such as the Young’s modulus, the yield strength, the ultimate tensile strength, etc., demonstrate a pronounced dependence on the average linear size $\overline{l}$ of the pores. For the first time, an empirical equation is proposed that correctly reproduces the dependence of the mechanical characteristics on the porosity $\varphi$ and on the average linear size $\overline{l}$ of the pores in a wide range of sizes: from nano-sized pores to pores of a few hundred microns in size. This equation correctly takes into account the limit case corresponding to the monolithic material. The obtained results can be used directly to solve applied problems associated with the design of materials with the necessary combination of physical and mechanical characteristics, in particular, porous metallic biomaterials.

Porous materials are widely used in many industries. However, their mechanical properties are inferior to those of their homogeneous non-porous analogues. In the present work, on the example of porous titanium nickelide, we studied the effect of the structure of the solid framework on the mechanical properties of the porous material. A method to improve the mechanical properties by achieving a uniform density profile along the strain direction is considered. It is shown that the uniform distribution of the crystalline matrix along the strain axis does not significantly affect on the mechanical properties of the porous system. The mechanism of pore collapse under compression has been investigated.

A model of nanoporous titanium nickelide is constructed, where the distribution of the thickness of the interpore bridges is qualitatively similar to the same distribution in experimentally obtained millimeter-sized samples. It is shown that the tensile strength of porous samples with a uniform density profile of a solid matrix is approximately 1.5 times greater and the Young’s modulus is approximately 1.3 times greater than that of samples with an uneven profile.

Due to the wide variety of porous materials, studying their properties can be laborious. This paper proposes a porous structure generation algorithm for molecular dynamics simulation, which simplifies and accelerates the study of porous material properties. The algorithm can generate a porous system with a specified porosity, pore size, and solid matrix distribution in the material. The algorithm successfully generates morphology similar to that of experimental samples. This is demonstrated through the example of NiTi intermetallic compound.

In view of the extensive use of porous materials, it is relevant to study their mechanical properties as a function of pore structure. The effect of pore structure anisotropy, which is evident as a nonuniform distribution of the solid matrix in the porous material, on mechanical properties under compression has been studied. The change in the anisotropic structure of porous nitinol under compression has been described. Differences in deformation processes in systems with different porosities have been identified.