Design and Compressive Fatigue Properties of Irregular Porous Scaffolds for Orthopedics Fabricated Using Selective Laser Melting

An irregular porous structure plays a major role in bone tissue engineering, and it is more suitable for bone tissue growth than a regular porous structure. The response surface method was used to establish a relationship between the average pore size and the design parameters. The technology of selective laser melting was utilized to fabricate the porous Ti-6Al-4V scaffolds with an irregularity of (0.4) and porosities of (70, 80, and 90%) designed using the Voronoi-tessellation method. Compression tests of porous scaffolds showed an elastic modulus range of 0.84-1.97 GPa and an ultimate strength ranging within 21.0-99.1 MPa. The elastic modulus was mainly influenced by the porosity and heat-treatment process. Furthermore, the fatigue test results suggested that the number of cycles (9 × 104 to 1.8 × 106) was greatly influenced by the porosity and heat-treatment process. The heat treatment of annealing greatly improved the fatigue performance of porous scaffolds. The irregular porous scaffolds with lower porosity and after full annealing exhibited the best fatigue behavior.