Ti-based Biomedical Materials Research,

The nano-sized calcium-deficient hydroxyapatite bioceramic coating on Ti-based materials with biologically gradient structure is obtained by electrodeposition-hydrothermal Synthesis and calcination in low Ca/P ratio solution. Though XRD half-quantitative analysis, SEM and TEM, the article analyzes the phase composition, the morphology of the coating and the bonding strength of the coating and the based material. The results show that: in electrodeposition, the parameters effect the content of HAP and the style of the growth and the formation of the crystals. The content of HAP in the coating increases with voltage and temperature increasing. When the value of pH is 4.5, the content of HAP is higher. Through control the parameters precisely, the HAP coatings with biologically gradient structure can be obtained to satisfy the requirement of biomaterials. After hydrothermal treatment, the coatings are composed by needle-like pure HAP, the Ca/P ratio is 1.61.After calcination under 700癈, the phase composition of coating does not change and the bonding strength of the coating increases with temperature increasing. After calcination above 800癈, a part of HAP change into p-Ca3(PO4)2, the content of which is effected by temperature; but the bonding strength of the coating decreases because of the appearance of the transition phase. A bioactive coating with biologically gradient structure and a biphasic HAP+ p-Ca3(P04)2 which is more benefit to bone growth is obtained, the bonding strength of the coating is high.The article investigates the preparation of high bioactivity and good mechanical properties of the Ti/HAP composites by high-energy ball milling and hot-press sinter. Through optical microscope, XRD analysis, SEM, TEM and FTIR analysis, the influence of ball-milling process on refinement and morphology of the mixed powder and density, hardness and microstructure of the sintered components are examined. The results show that: under constant rotation rate, when use dry-balling, increasing the duration of balling can greatly refine HAP powder, but has almost no influence on refinement of Ti powder; under this condition, large powder of Ti are packed and wrapped by the fine powder ofHAP. When use wet-milling, increasing the duration of balling can obviously refine both powder of Ti and HAP, and tow mixed powders mixed together. After high-energy ball milling, the materials are almost fully densified even sintered at 1000?C. In the meantime, by using wet-milling, in the short duration of balling, sintered Ti substrate comprise an encircled and connected net in which HAP is homogenously dispersed. This composite has not only bearing high loads properties, but also excellent bioactivity. Ti/HAP is one of ideal bioactive materials.