Preparation Of Porous Hydroxyapatite Ceramics And Strength Improvement

Bioceramic materials have not only good biocompatible but also can form chemically combination with bone and cartilage tissue. It is restricted in load-bearing because of its brittle and lower flexural strength. Hence, how to improve the mechanical properties is a key probllem in present research.The paper discusses the structure, performance, applications and preparation method of porous ceramics by the numbers and emphasize the preparation of Hydroxyapatite and the method of strength improvement. The study adopted the impregnation of polyurethane sponges method to produce highly porous HA ceramic scaffolds and improve the mechanical properties by several methods which including different concentration of PDLLA coating, hot isostatic pressing and optimization of grain shape.The porosity of porous HA scaffold was measured by gravimetry method. The composition, macro- and micro-porous structures and mechanical properties of the porous HA scaffold was investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM) and compressive test.The experimental results show that: 1, Impregnation of polyurethane sponges with ceramic slurry adopted can produce highly porous HA ceramic scaffolds with a 3D interconnected structure. The porosity reached 95% with homogeneous pore size. 2, The compressive strength of porous HA scaffold can be improved by immersion in polymer coating which is higher and higher with increase of polymer concentration and the porosity always the same. 3, The HIP technique can effectively improve the sintering property and densification of porous HA ceramic scaffolds so induce the increase of the compression strength. 4, The compressive strength of scaffold prepared by different gain shape represents obviously diversity. The spherical powder shows more excellent mechanical properties than other grain shape.