**Abstract**

The objective of this chapter is to focus on finding mechanical properties for two models defined as core-filled model (Type 1) and core-spaced model (Type 2) created by direct metal laser sintering (DMLS). Applied material is aluminum alloy AlSi10Mg powder and each model is created as a vertical additive manufacturing with DMLS. After quasi-static compression, Type 1 showed 19% higher elastic modulus, 12% higher compressive yield strength, and 51.6% higher elongation than Type 2. By uniaxial compressive test, there found two issues that can be the reasons to make weaker models by 3D printing were found: melted metals by DMLS are not connected with each other preciously and a space in additive layer when additive manufacturing makes a shape of specimen. In addition, anisotropy is the significant factor to decide stiffness or strength. In nearby future, various kinds of unit models such as core-filled or corespaced model hope to be made a sandwich core structure and to be investigating more deeply about bending or shear properties continuously. In the near future, it is hoped that we see more upgraded 3D printing techniques for making aerospace materials.

**Keywords:** cellular solids, open cell unit model, closed cell unit model, honeycomb, stiffness, strength
