Mechanical Behavior of Ti6Al4V Scaffolds Filled with CaSiO3 for Implant Applications

Abstract

Triply periodic minimal surfaces (TPMS) are becoming increasingly attractive due to their biomedical applications and ease of production using additive manufacturing techniques. In the present paper, the architecture of porous scaffolds was utilized to seek for the optimized cellular structure subjected to compression loading. The deformation and stress distribution of five lightweight scaffolds, namely: Rectangular, primitive, lattice, gyroid and honeycomb Ti6Al4V structures were studied. Comparison of finite element simulations and experimental compressive test results was performed to illustrate the failure mechanism of these scaffolds. The experimental compressive results corroborate reasonably with the finite element analyses. Results of this study can be used for bone implants, biomaterial scaffolds and antibacterial applications, produced from the Ti6Al4V scaffold built by a selective laser melting (SLM) method. In addition, Ti6Al4V manufactured metallic lattice was filled by wollastonite (CaSiO 3 ) through spark plasma sintering (SPS) to illustrate the method for the production of a metallic-ceramic composite suitable for bone tissue engineering.Gradient structures, unit cell size, strut diameter, the volume fraction the of sample, plasticity and damage tolerance, as well as the minimizing of cost/time are considered during the computer-aided design (CAD) and simulation. In order to have optimized lightweight structures under loading and in vivo or in vitro conditions, printed scaffolds can be graded axially or radially [12]. Recently, research is focused upon polymeric printing using polyjet/inkjet deposition [13], which is faster with no post-processing, unlike metal printing. However, the low mechanical properties of polymer 3D printed materials make it non-applicable for in vivo conditions. Porous Ti6Al4V structures have yield strength and compressive strength in the range of 90-220 MPa [14]. The computer-aided design (CAD) of porous scaffolds and finite element analysis (FEA) have recently attracted much attention in the tissue engineering field. Fluid permeability [15] and biocompatibility [16] of scaffolds depends directly on the pore geometry and topology [17] of structures. The curved shape, smoothness, good flowability, 3D manufacturability and biocompatibility of Ti6Al4V powder particles makes Ti-based alloy promising for load bearing bone implants [18]. It is well known that the artificial bone scaffolds should have the following characteristics: (1) Biocompatibility with living tissues; (2) mechanical properties for trabecular bone and cortical bone (ranging from 0.7 to 15 MPa till >100 MPa [19]); and (3) porous fabricated structures for osteoporosis diseases. Periodic porous materials like TPMS are potential candidates for biomimetic scaffold architecture [19]. The main advantage of TPMS scaffolds is the open interconnected cell structure, deemed to facilitate cell migration, vitalization and vascularization, while retaining a high degree of structural stiffness [20]. Henceforth, mechanical ...

Prospect of Metal Ceramic (Titanium-Wollastonite) Composite as Permanent Bone Implants: A Narrative Review

“…Wollastonite is a versatile industrial mineral that is used in ceramics, cements, paints, paper, and plastics [ 107 ]. The versatility of wollastonite has generated much interest due to its promise as a potential implantable material because it can form bonds with bone tissue through the development of a biological apatite layer on the surface [ 10 , 108 ]. Materials with this characteristic are known as bioactive materials and are widely used in medical and dental applications.…”

“…Materials with this characteristic are known as bioactive materials and are widely used in medical and dental applications. Many studies have been performed to produce bioactive materials for various applications, such as implantable materials [ 10 , 11 , 108 , 109 , 110 ].…”

Special Issue on “Biomaterials for Bone Tissue Engineering”

“…The mechanical performance of scaffolds is of utmost importance in BTE for two main reasons: (i) the scaffold should present an overall stiffness similar to the natural bone tissue [2], and (ii) the mechanical stimuli at the bone-biomaterial surface have been evidenced as an important design parameter in BTE scaffolds [3]. In this context, Rahmani et al [4] evaluated in silico the mechanical performance of additively manufactured BTE scaffolds. Moreover, the scaffolds were experimentally characterized by means of compressive tests.…”

The Impact Resistance of Highly Densified Metal Alloys Manufactured from Gas-Atomized Pre-Alloyed Powders

“…The defective layer can be improved during sintering of the next layer of powders [4,5]. Ti6Al4V is an α + β titanium martensitic microstructure alloy widely used in the aerospace and biomedical industries, along with 316L, due to its excellent mechanical, chemical, biocompatible, and lightweight character [6][7][8]. The AM technique and its subset, three-dimensional (3D) printing, is an approach for the rapid prototyping of a wide range of metals and ceramics, complex geometries and structures, and small or large size objects in form of lattice or solid directly produced from the computer-aided model (CAD).…”