纳米缺钙羟基磷灰石生物陶瓷涂层中相组成和显微结构的控制

Control of the Microstructure and the Phase Composition in the Nano-sized Calcium-deficient Hydroxyapatite Bioceramic Coating

研究了低钙磷比溶液电沉积缺钙羟基磷灰石生物陶瓷涂层在水热合成和700℃,800℃,900℃焙烧后的相组成和显微组织结构;用扫描电镜(SEM)、X射线衍射(XRD)和透射电镜(TEM)对涂层进行分析。结果表明:在电沉积液Ca/P比1.30,沉积液温度25℃,电压4V条件下,Ti基体表面沉积了片状和条状HAP和CaHPO4·2H2O混合相涂层;在pH值为12的碱液中,150℃和200℃水热合成4h后涂层由针状纯HAP组成,Ca/P比约为1.61,且随着水热合成温度的升高,晶体结晶度提高,但晶体无明显长大趋势;700℃焙烧后,涂层仍由纯HAP组成,只是晶体因失水而发生团聚;800℃焙烧后,部分HAP发生分解,生成β-Ca3(PO4)2,且HAP与β-Ca3(PO4)2的体积比为90∶10,形貌为块状和板条状,其表面附着许多细小的针状颗粒;900℃焙烧后,β-Ca3(PO4)2的含量增加,HAP与β-Ca3(PO4)2的体积比为74∶26,小颗粒团聚成较大的块状和板条状颗粒。由此制备了对骨组织生长更有利的HAP+β-Ca3(PO4)2双相涂层结构。

The microstructure and the phase composition of hydroxyapatite bioceramic coating in low Ca/P ratio by electrodeposition-hydrothermal synthesis and calcination at 700degreesC, 800degreesC and 900degreesC are studied. SEM, XRD and TEM are used to analyze the coating. The results show that the mixed coatings of plate-like and strip-like HAP and CaHPO(4) . 2H(2)O are obtained on the surface of Ti in the solution of Ca/P ratio, of 1.30 and at 25degreesC and 4V. After hydrothermal treatment in the solution of 150degreesC and 200degreesC with a pH value of 12 for 4h, the coatings are composed by needle-like pure HAP, the Ca/P ratio is 1.61. With the increase of temperature, the crystal does not grow obviously, but the degree of crystallization increases. The phase composition of coating does not change after the calcination at 700degreesC, but the particles aggregated because of lose of the water. After calcination at 800degreesC and 900degreesC, a part of HAP change into beta-Ca(3)(PO(4))(2), the volume ratio is 90: 10 and 74:26 respectively, the crystals lump into plate-like and band-like particles. With increase of temperature, the aggregation becomes distinct. A coating of biphasic HAP + beta-Ca(3)(PO(4))(2) is obtained which is more benefit to bone growth.