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采用SEM、TEM、XRD和EDX等试验手段对经150~400 V电压微弧氧化处理后工业纯钛(Ti)和Ti-40%Nb(Ti-40Nb)(质量分数)合金表面磷酸钙(CaP)涂层的显微组织、物理和力学性能以及化学特性进行研究。结果表明:在两种基体上所得到的涂层厚度、粗糙度和结构元尺寸显示出相似的线性特征且与处理电压有关。扫描电镜(SEM)分析表明,磷酸钙涂层为多孔形态,表面呈粗糙浮雕状。XRD和TEM分析结果表明,微弧磷酸钙涂层呈非晶态结构。当氧化电压增加至300~400 V时,涂层中形成了结晶相,如CaHPO_4、β-Ca_2P_2O_7。经过退火处理,涂层中形成复杂的多相结构,如CaTi_4(PO_4)6、β-Ca_2P_2O_7、TiP_2O_7、TiNb(РО_4)3、TiO_2、NbO_2和Nb_2O_5。当氧化电压为200~250 V、处理时间为5~10 min时,在工业纯钛和Ti-40Nb合金表面形成的涂层显示出最佳特性,其厚度为40~70μm,孔隙率为20%~25%,粗糙度(Ra)为2.5~5.0μm,粘合强度为15~30 MPa,Ca与P最佳摩尔比为0.5~0.7。
The effects of micro-arc oxidation of industrial pure titanium (Ti) and Ti-40% Nb (Ti-40Nb) (mass fraction) on the surface of CaP ) Coating microstructure, physical and mechanical properties and chemical properties of the study. The results show that the coating thickness, roughness and structure element sizes obtained on both substrates show similar linear characteristics and are related to the process voltage. Scanning electron microscopy (SEM) analysis showed that the calcium phosphate coating was porous and the surface was rough and embossed. XRD and TEM results show that the micro-arc calcium phosphate coating is amorphous. When the oxidation voltage was increased to 300 ~ 400 V, the crystal phase formed in the coating, such as CaHPO 4 and β-Ca 2 P 2 O 7. After annealing, the coating has complex multiphase structures such as CaTi 4 (PO 4) 6, β-Ca 2 P 2 O 7, TiP 2 O 7, TiNb (3), TiO 2, NbO 2 and Nb 2 O 5. When the oxidation voltage is 200-250 V and the treatment time is 5-10 min, the coatings formed on the surfaces of industrial pure titanium and Ti-40Nb alloy show the best properties with a thickness of 40-70 μm and a porosity of 20% To 25%, the roughness (Ra) is 2.5-5.0 μm, the bonding strength is 15-30 MPa, and the optimum molar ratio of Ca and P is 0.5-0.7.