Biomechanics of Additively Manufactured Metallic Scaffolds—A Review

Abstract

This review paper is related to the biomechanics of additively manufactured (AM) metallic scaffolds, in particular titanium alloy Ti6Al4V scaffolds. This is because Ti6Al4V has been identified as an ideal candidate for AM metallic scaffolds. The factors that affect the scaffold technology are the design, the material used to build the scaffold, and the fabrication process. This review paper includes thus a discussion on the design of Ti6A4V scaffolds in relation to how their behavior is affected by their cell shapes and porosities. This is followed by a discussion on the post treatment and mechanical characterization including in-vitro and in-vivo biomechanical studies. A review and discussion are also presented on the ongoing efforts to develop predictive tools to derive the relationships between structure, processing, properties and performance of powder-bed additive manufacturing of metals. This is a challenge when developing process computational models because the problem involves multi-physics and is of multi-scale in nature. Advantages, limitations, and future trends in AM scaffolds are finally discussed. AM is considered at the forefront of Industry 4.0, the fourth industrial revolution. The market of scaffold technology will continue to boom because of the high demand for human tissue repair.

Forged to heal: The role of metallic cellular solids in bone tissue engineering

“…Typically, the modulus of human trabecular bone ranges between 10 and 3000 MPa while titanium alloys range from 55 to 114 GPa and magnesium alloys between 40 and 60 GPa. Cellular solids, on the other hand, can reach elastic moduli in the range of few GPa [ 44 , 45 ], and results as low as 2.87 GPa have been reported for titanium [ 143 ]; Spinal cage implants [ 5 , 144 , 145 ]: spinal fusion is a surgical procedure used to treat a range of spinal conditions, including degenerative disc disease, spinal fractures, and spinal deformities. The goal of spinal fusion is to stabilize the spine and promote fusion of the two vertebrae, reducing pain and restoring function.…”

“…Spinal cage implants [ 5 , 144 , 145 ]: spinal fusion is a surgical procedure used to treat a range of spinal conditions, including degenerative disc disease, spinal fractures, and spinal deformities. The goal of spinal fusion is to stabilize the spine and promote fusion of the two vertebrae, reducing pain and restoring function.…”

Design of Ti64/Ta Hybrid Materials by Powder Metallurgy Mimicking Bone Structure

“…Recently, another widely used alternative for producing porous materials has increased in popularity, and it involves the additive manufacturing (AM). Notable results have been reported for the AM used to fabricate cellular materials that mimic the structure that composes the spongy bone by using highly complex geometric shapes for the pores [ 2 , 15 , 16 , 17 , 18 , 19 ]. Specifically, the typical tests of mechanical properties obtained by AM are in the range of values presented by the spongy bone, because the porosity reached with this technique is really high, around 90%.…”

Influence of Fused Deposition Modelling Nozzle Temperature on the Rheology and Mechanical Properties of 3D Printed β-Tricalcium Phosphate (TCP)/Polylactic Acid (PLA) Composite

“…The printing bed lowers after each entirely constructed layer by a distance equal to the layer height. This allows the next layer to get extruded and bonded to the previous one [ 30 ]. Notably, the material used in the FDM process must have specific rheological properties that allow it to get extruded through the nozzle without clogging it then be deposited on the bed and retain its shape.…”