A novel method for production of foamy core@compact shell Ti6Al4V bone-like composite

This paper presents a novel method for fabrication of bone-like Ti6Al4V foamy core@compact shell composite for utilization as substitutive implant for cortical bone having porous core. Seven prototypes with core-diameters of 0, 6, 8, 10, 12, 14 and 16 mm surrounded by dense shells of respective thicknesses 8, 5, 4, 3, 2, 1 and 0 were produced by an innovative two-stage packing/compaction sintering method. Density, porosity, Young's modulus and compression strength of the prototypes depended on the core diameter. Mechanical strength and Young's modulus of 10@16 (10 mm core, 16 mm diameter prototypes) resembled that of the human ulna bone. Creation of foam at the center was achieved by carbamide powder space holder. Sintering potential model of porous spaces was a basis for heat treatment. Yield strength and Young's modulus of the prototypes ranged from 501 MPa to 46 GPa in the compact shells and 7 MPa to 2 GPa in the foamy cores of the composite samples. Final products contained 8-65% porosity with 1.45-2.84 g/cm3 theoretical density which were within the range of the real human bone.