Quasi-Static compressive responses and fatigue behaviour of Ti-6Al-4 V graded lattice structures fabricated by laser powder bed fusion

Abstract

Graded lattice structures have been paid wide attention in the engineering and biological fields due to their excellent energy absorption capacity and variable porosity characteristics. Based on the size-graded lattice structure, laser powder bed fusion is utilized to manufacture the corresponding Ti-6Al-4 V lattice samples. Then, the quasi-static compression experiment is conducted and a predictive model for its mechanical properties is established accordingly. Also, its dynamic fatigue behavior is studied, and the influence of sandblasting and gradient direction on its mechanical response is evaluated. The results show that excellent mechanical properties and energy absorption capacity is exhibited in the vertical graded (VG) structure. Compared to the uniform structure, its elastic modulus and energy absorption are increased by 17.53% and 59.43%, respectively. The compression response of the radial graded (RG) structure is similar to that of the uniform structure, with minor changes on the mechanical properties and energy absorption capacity. However, the fatigue performance of the RG structure is better than that of the VG structure. With appropriate mechanical properties and changes in pores, this graded structure can simulate the changing physical and chemical properties of natural bone. Therefore, it has great potentiality in the application of bone implants.

Keywords

• Graded lattice structures
• Ti-6Al-4V
• Mechanical properties
• Fatigue behaviour
• Bone implants