Bone-inspired AZ31/HA composites with gradient structures and properties for implant applications

Abstract

The increasing demand for lightweight, damage-resistant, wear-resistant, and corrosion-resistant materials in implant applications has driven the development of novel bone-inspired composites. This study introduces AZ31 (Mg–3Al–1Zn)/hydroxyapatite (HA) composites fabricated using centrifugal freeze casting and pressureless infiltration. The unique formation mechanism and structure-property relationship of these composites were investigated. The gradient distribution of HA particles and the nucleation and growth behavior of ice crystals, influenced by varying solid content in the centrifugal field, resulted in a radially increasing ceramic-layer-to-metal-layer thickness ratio. Consequently, the composites exhibited a gradient distribution of compression strength, hardness, wear resistance, and corrosion resistance. Moreover, the composites showed no cytotoxicity and promoted osteoblast proliferation, making them suitable for bone tissue engineering applications. These findings provide valuable insights for developing new materials in bone tissue engineering and pave the way for future research in this field.

Keywords

• Freeze casting
• Liquid metal infiltration
• Metal-matrix composites (MMCs)
• Mechanical properties