Fabrication of titanium foams by calciothermic reduction (Calciofoam)

泡沫钛具有广泛的应用前景。该项目的目的是利用钙热低温还原法制备的细钛粉来增强所研究的泡沫钛的性能。本课题的重点之一是利用空间支架法制备大孔泡沫钛。另一个重点是制备用于催化和超级电容器储能应用的微孔和纳米孔泡沫钛。大孔泡沫钛（60-80体积%）由于增强骨附着和优异的生物相容性，在生物医学应用中具有很大的兴趣。此外，骨骼的杨氏模量与种植体材料之间的不匹配可以通过防止种植体松动的孔隙度来减少。为了保证足够的机械强度，这些大孔泡沫是用我们在原项目框架下合成的细TiH2粉末通过钙热还原法制备的。这些小颗粒形成了极细粒度的钛结构，具有很高的机械强度。本项目的第二个目标是制备微孔和纳米孔泡沫材料，这些材料是通过铁钛样品的合金化制备的。这些试样是由钙热还原的FeTiO3粉末压制烧结而成的。脱合金过程将在热乙酸中进行。泡沫钛自然地被一层薄薄的钝化层覆盖，这是催化和超级电容器应用的功能部分。二氧化钛纳米颗粒是水净化的重要催化剂，但为了技术上的方便，需要一种用于颗粒的支架，这可以通过这些高表面积泡沫来解决。对粉末和泡沫进行结构和化学表征，以便将其与机械和功能特性联系起来。

Titanium foams are of great interest for a variety of applications. The goal of the project are enhanced properties of the studied titanium foams using fine titanium powders prepared by calciothermic low temperature reduction. One focus of the project is the preparation of macroporous titanium foams using the space holder method. The other focus is the preparation of micro- and nanoporous titanium foams for catalytic and energy storage applications as for supercapacitors. Macroporous titanium foams (60-80 vol.%) are of great interest for biomedical applications due to the enhanced bone attachment and excellent biocompatibility. Additionally, the mismatch between Young’s modulus of bone and implant material can be reduced by the porosity which prevents implant loosing. In order to guarantee sufficient mechanical strength those macroporous foams are fabricated with fine TiH2 powders synthesized in the frame of our former project by calciothermic reduction. Those small particles result in an extremely fine-grained titanium structure with high mechanical strength. The second goal of this project is the preparation of micro- and nanoporous foams prepared by dealloying of FeTi-specimens. Those specimens are prepared from calciothermically reduced FeTiO3 powder which are pressed and sintered afterwards. The dealloying procedure will be carried out in hot acetic acid. The titanium foams are naturally covered by a thin passivation layer which is the functional part for catalytic as well as supercapacitor applications. TiO2 nanoparticles are important catalysts for purification of water but for technical convenience a scaffold for the particles is aspired which could be solved by these high surface area foams. Structural and chemical characterization of powders and foams are carried out in order to correlate them with their mechanical and functional properties.