Compression deformation and fracture behaviors of laser powder bed fusion Ti-6Al-4V cellular solid during in situ tests

Laser powder bed fusion (LPBF) is a novel process for fabricating cellular solids with a specific porosity and pore structure. To identify the uniaxial compressive properties and detailed fracture behavior of a LPBF Ti-6Al-4V cellular solid with a cubic unit cell, in situ mechanical tests and digital image correlation were performed in this study. The results showed that the compressive stress-strain curve of the cellular solid with a cubic unit cell was apparently serrated, and this type of stress-strain curve is generally classified as a brittle cellular solid. However, the findings from the in situ test clearly indicated that the vertical struts were obviously deformed without cracking before fracture, and strain localization occurred in the center of the vertical struts. The fracture surface also shows that the fracture mode was predominantly ductile. Therefore, the compressive properties and fracture mode of a cellular solid must be precisely identified by using the stress-strain curve in combination with in situ tests and fracture surface analysis.

Automated summary

This study utilized in situ mechanical tests and digital image correlation to investigate the fracture behavior and compressive properties of LPBF Ti-6Al-4V cellular solids. The results revealed unique fracture behavior and compressive properties, highlighting the importance of utilizing stress-strain curves and in situ tests to accurately determine the performance and fracture mode of cellular solids.