Advanced Materials Research Group, Faculty of Engineering, University of Nottingham, Nottingham, UK.
Sci Rep. 2018 Sep 28;8(1):14530. doi: 10.1038/s41598-018-32612-x.
Here we show a new and effective methodology for rapid/controllable porosification of thin-film ceramics, which may be applied in medical devices/electronics and membrane nano-filtration. Dense hydroxyapatite applied to Ti6Al4V by plasma-assisted PVD was electron-beam irradiated to induce flash melting/boiling. Deposited coatings contained amorphous and nano-crystalline/stoichiometric hydroxyapatite (35 nm). Irradiation (voltages 13-29 kV) led to ablation (up to 45% mass loss) and average/maximum pore areas from (0.07-1.66)/(0.69-92.53) μm, mimicking the human cortical bone. Vitrification above 1150 °C formed (62-30 nm) crystallites of α-Tri Calcium Phosphate. Unique porosification resulted from irradiation-induced sub-surface boiling and limited thermal conductivity of hydroxyapatite, causing material to expand/explode through the more quickly solidified top surface. Commercially applicable, roughened Ti6Al4V exacerbated the heating and boiling explosion phenomenon in certain regions, producing an array of pore sizes. Scaffold-like morphologies were generated by interconnection of micron/sub-micron porosity, showing great potential for facile generation of a biomimetic surface treatment for osseointegration.
在这里，我们展示了一种新的、有效的薄膜陶瓷快速/可控多孔化方法，该方法可应用于医疗器械/电子和膜纳米过滤。通过等离子体辅助 PVD 将致密的羟基磷灰石应用于 Ti6Al4V，然后用电子束辐照诱导瞬间熔化/沸腾。沉积的涂层含有非晶态和纳米晶/化学计量羟基磷灰石（35nm）。辐照（电压 13-29kV）导致烧蚀（高达 45%的质量损失）和平均/最大孔径（0.07-1.66/0.69-92.53μm），模拟了人类皮质骨。在 1150°C 以上的玻璃化形成了（62-30nm）α-磷酸三钙的晶相。辐照诱导的次表面沸腾和羟基磷灰石有限的导热性导致材料通过更快凝固的上表面膨胀/爆炸，从而产生独特的多孔化。商业上适用的、粗糙的 Ti6Al4V 在某些区域加剧了加热和沸腾爆炸现象，产生了一系列不同大小的孔径。通过微米/亚微米孔隙的互连形成了支架样形态，为易于生成仿生表面处理以实现骨整合提供了巨大潜力。
