Paital Sameer R, Dahotre Narendra B
Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA.
Biomed Mater. 2007 Dec;2(4):274-81. doi: 10.1088/1748-6041/2/4/011. Epub 2007 Nov 13.
In the present paper the feasibility of depositing a porous calcium phosphate (CaP) bio-ceramic coating using a continuous wave Nd:YAG laser on a Ti-6Al-4V substrate has been demonstrated. The advantages offered by such porous bio-ceramic coating are its inertness combined with the mechanical stability of the highly convoluted interface that develops when bone grows into the pores of ceramic. The formation of different phases with varying laser fluences is studied using x-ray diffraction (XRD). A quantitative estimation of the crystallite size and relative amounts of Ti and other predominant phases such as TiO(2) and alpha-tricalcium phosphate (alpha-TCP) were obtained. An increase in the crystallite size with increasing laser fluence is observed for all the above three phases. It is observed that TiO(2) is the predominant phase for all laser fluences and there is an increase in the alpha-TCP phase with increasing laser fluence. Surface porosity measurements indicated a decreasing trend with increasing laser fluence. Microhardness measurements in the cross section of samples showed a maximum hardness within the coating. The bioactivity of the coatings was further demonstrated by the formation of an apatite-like layer on the surface of the sample after being immersed in a simulated biofluid.
在本论文中，已证明了使用连续波Nd:YAG激光在Ti-6Al-4V基体上沉积多孔磷酸钙（CaP）生物陶瓷涂层的可行性。这种多孔生物陶瓷涂层的优点在于其惰性，以及当骨长入陶瓷孔隙时形成的高度复杂界面的机械稳定性。利用X射线衍射（XRD）研究了不同激光能量密度下不同相的形成情况。获得了微晶尺寸以及Ti和其他主要相（如TiO₂和α-磷酸三钙（α-TCP））相对含量的定量估计。观察到上述三相的微晶尺寸均随激光能量密度的增加而增大。据观察，对于所有激光能量密度，TiO₂都是主要相，且α-TCP相随激光能量密度的增加而增多。表面孔隙率测量表明，其随激光能量密度的增加呈下降趋势。样品横截面的显微硬度测量显示涂层内硬度最大。将样品浸入模拟生物流体后，在其表面形成了类磷灰石层，进一步证明了涂层的生物活性。
