Microstructure of Co-Cr Alloy Products with Three-Dimensional Geometry Fabricated by Laser Beam Sintering

Abstract

The development of the implant material which works much like bone must be an intrinsic approach to reduce the mechanical mismatch. Bone expresses the anisotropy of the mechanical characteristics based on the microstructual adaptation attributed to the apatite c-axis orientation corresponding to in vivo stress distribution. Therefore, the control of microstructure of implant material was performed by laser beam sintering technique aiming at the modification of mechanical property. The Co-Cr alloy products with three-dimensional geometry were successfully fabricated by laser beam sintering based on the design model. The grain showed an elongated dendritic morphology and aligned along the build direction during laser beam sintering. The crystallographic texture was developed responsible for the macroscopic heat flow along the build direction rather than the macroscopic one through the structures. Thus, the microstructure involving the grain morphology and crystallographic texture formation was anisotropically controlled by laser beam sintering technique. The mechanical properties could be modified anisotropically by the oriented microstructure in the Co-Cr alloy structures with three-dimensional geometry for the biomedical applications.