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激光熔覆过程中医用钛合金与混合粉末(CaHPO_4·2H_2O+CaCO_3+La_2O_3)因热膨胀系数相差大而容易产生裂纹、气孔等缺陷,故采用梯度设计方法在医用钛合金表面上制备一层具有生物活性的磷酸钙陶瓷涂层。通过金相显微镜(OM),X射线衍射仪(XRD),显微硬度计,甲基噻唑基四唑(MTT)比色法和倒置荧光显微镜对稀土氧化物La_2O_3添加量相同(0.6%)的不同钙磷比激光熔覆磷酸钙陶瓷涂层结合界面、物相、显微硬度、细胞相对活性和细胞生长状态进行分析。试验结果表明:通过OM观察其横截面积可以看出熔覆试样分为基材、合金化层及陶瓷层3个区域,各区域间呈良好的冶金结合。在2θ在32°~33°附近,当n(Ca)∶n(P)(原子比)=1.40~1.45时,其XRD图谱中羟基磷灰石+β-磷酸三钙(HA+β-TCP)的特征峰较高,表明其生成的生物活性相HA+β-TCP的量最多。显微硬度结果表明n(Ca)∶n(P)值越大,涂层平均硬度越高。MTT比色法和倒置荧光显微镜观察结果表明当涂层n(Ca)∶n(P)=1.40时,吸光度值(OD)最大,生物陶瓷涂层上细胞数量最多且生长状态良好,表明该涂层具有最佳的细胞相容性且有利于细胞的稳定增殖与生长。
In the laser cladding process, the defects of the titanium alloy and the mixed powder (CaHPO 4 2H 2 O + CaCO 3 + La 2 O 3) are easy to produce cracks and pores due to large difference in thermal expansion coefficient. Therefore, a gradient design method is used to prepare a layer of bio- Activated calcium phosphate ceramic coating. The rare earth oxide La_2O_3 (0.6%) was added in the same amount by the optical microscope (OM), X-ray diffraction (XRD), microhardness tester, MTT colorimetric method and inverted fluorescence microscope The interface, phase, microhardness, relative cell viability and cell growth state of different Ca and P laser clad calcium phosphate ceramic coatings were analyzed. The experimental results show that the cross-sectional area of the cladding sample is divided into three regions: substrate, alloying layer and ceramic layer. The metallurgical bonding between the two regions shows good metallurgical bonding. The XRD patterns of hydroxyapatite + β-tricalcium phosphate (HA + β-TCP) in the vicinity of 2 ° at 32 ° -33 ° when the ratio of n (Ca) ) Higher peak, indicating that the generation of bioactive phase HA + β-TCP amount the most. The microhardness results show that the larger the n (Ca): n (P) value, the higher the average hardness of the coating. The results of MTT assay and inverted fluorescence microscopy showed that when the coating n (Ca): n (P) = 1.40, the absorbance value (OD) was the largest, the number of cells on the bioceramic coating was the most and the growth state was good, Layer has the best cell compatibility and is conducive to the stable cell proliferation and growth.