Study on Topology Optimization Design, Manufacturability, and Performance Evaluation of Ti-6Al-4V Porous Structures Fabricated by Selective Laser Melting (SLM)

Abstract

Abstract:The combination of topology optimization (TOP) and selective laser melting (SLM) provides the possibility of fabricating the complex, lightweight and high performance geometries overcoming the traditional manufacturing "bottleneck". This paper evaluates the biomechanical properties of porous structures with porosity from 40% to 80% and unit cell size from 2 to 8 mm, which are designed by TOP and manufactured by SLM. During manufacturability exploration, three typical structures including spiral structure, arched bridge structure and structures with thin walls and small holes are abstracted and investigated, analyzing their manufacturing limits and forming reason. The property tests show that dynamic elastic modulus and compressive strength of porous structures decreases with increases of porosity (constant unit cell size) or unit cell size (constant porosity). Based on the Gibson-Ashby model, three failure models are proposed to describe their compressive behavior, and the structural parameter λ is used to evaluate the stability of the porous structure. Finally, a numerical model for the correlation between porous structural parameters (unit cell size and porosity) and elastic modulus is established, which provides a theoretical reference for matching the elastic modulus of human bones from different age, gender and skeletal sites during innovative medical implant design and manufacturing.

Predicting the output dimensions, porosity and elastic modulus of additive manufactured biomaterial structures targeting orthopedic implants

“…Selective Laser Melting is an additive manufacturing layer-wise process able to fabricate 3D components based on computer-aided design (CAD) data [1][2][3]. SLM versatility allows the fabrication of customized and complex geometries such as metallic cellular structures [4][5][6].…”

Determination of the Elasticity Modulus of 3D-Printed Octet-Truss Structures for Use in Porous Prosthesis Implants

“…The type of the unit cell is a key factor for the biological and mechanical properties of the porous structures, with regards to the bone tissue regeneration [38]. With the help of the compression test, the compressive strength and elastic modulus of the printed structures can be assessed so that they match the requirements of different structures [39]. The study of the bone matrix showed that the increase or decrease in bone mass were related to its stress–strain state [40].…”

Complete Removal of Residual Particles and Realization of Mechanical Properties to Improve Osseointegration in Additively Manufactured Ti6Al4 V Scaffolds through Flowing Acid Etching

“…The sheets were also rinsed with deionized water. Following drying, the scaffolds and sheets were heated to 800 °C in an argon atmosphere and maintained at this temperature for 4 h to eliminate residual stress and improve the mechanical properties. , Subsequently, the scaffolds and sheets were allowed to cool to room temperature inside the furnace.…”