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为了更好地探索稀土氧化物对生物陶瓷涂层组织形貌与降解性能的影响,在添加稀土氧化物La_2O_3的情况下,利用激光熔覆技术,结合梯度成分设计与梯度功率烧结,在钛合金表面制备了一层含羟基磷灰石(HA)和β-磷酸三钨(β-TCP)的梯度生物陶瓷涂层。经过X衍射分析仪(XRD)、扫描电镜(SEM)、电感耦合等离子体原子发射光谱(ICP-AES)的分析发现:(1)稀土氧化物的加入,能够促进涂层生成HA和β-TCP,改善涂层表面在模拟体液中的开裂敏感性以及细化新生类骨磷灰石晶粒尺寸。当稀土添加量为0.4%时,涂层中HA和β-TCP衍射峰值最高,在模拟体液中浸泡14 d后,涂层表面无裂纹,形成分布均匀,大小一致的类骨磷灰石。(2)涂层在模拟体液中浸泡28 d后的降解率为0.2126%。模拟体液中Ca~(2+)和La~(3+)浓度随着浸泡时间发生变化,其中Ca~(2+)浓度呈动态的上下波动变化,且含量逐渐减小,表明Ca~(2+)从模拟体液中沉积到涂层表面的量要比涂层降解到溶液中的多;而La~(3+)浓度随浸泡时间增加而逐渐增大,在将La~(3+)浓度与浸泡时间在取对数的情况下,两因素存在明显的线性关系,并推导出关于La~(3+)浓度,浸泡时间与涂层浸泡面积的经验公式。
In order to explore the effect of rare earth oxide on the morphology and degradation of bioceramic coating, laser cladding technology, gradient composition design and gradient power sintering were used in the case of rare earth oxide La 2 O 3. A gradient bioceramic coating containing hydroxyapatite (HA) and tris-tris (t-TCP) was prepared on the surface. The results of X-ray diffraction (XRD), scanning electron microscopy (SEM) and inductively coupled plasma atomic emission spectrometry (ICP-AES) show that: (1) The addition of rare earth oxides can promote the formation of HA and β-TCP , To improve the susceptibility of the coating surface to cracking in simulated body fluids and to refine the size of the nascent bone apatite. When the content of rare earth is 0.4%, the diffraction peaks of HA and β-TCP in the coating are the highest. After soaking in simulated body fluid for 14 days, the surface of the coating is free of cracks, forming homogeneous and uniform bone-like apatite. (2) The degradation rate of coating after soaking in simulated body fluid for 28 d was 0.2126%. The concentration of Ca 2+ and La 3+ in simulated body fluid changed with the immersion time, in which Ca 2+ concentration fluctuated dynamically and decreased gradually, indicating that Ca 2+ +) Deposition from the simulated body fluid to the coating surface than the coating solution to the degradation of more; and La ~ (3 +) concentration increases with the immersion time and gradually increased, the concentration of La ~ (3 +) When the logarithm of the soaking time is taken, there is a clear linear relationship between the two factors, and the empirical formula about the concentration of La 3+, the soaking time and the soaking area of the coating is deduced.