Design and manufacturing of graded high-purity magnesium-calcium-zinc-material by fractional crystallization for the application as biodegradable implant material

本研究项目的目的是开发一种创新的替代真空蒸馏的制造工艺，以生产高纯度镁，用于作为可生物降解的植入材料。由于该方法是基于分馏结晶的方法，因此该高纯镁和镁合金的生产方法在降低设备投资的同时提高了生产速度和资源效率。利用“条纹”现象，合金元素（如钙和锌）将被整合到衬底材料中，并在横截面上增加浓度，但在一个加工步骤内，而不需要目前需要的再熔化步骤。随着梯度镁材料的生产，目前无法实现的降解设计在文献中被定义为在提高降解速率之前缓慢开始的最佳降解设计可以实现。关于降解过程的研究将确认分级结晶在制造方面的适用性，以及目标降解设计，同时表征发生在分级材料中的腐蚀机制。为了实现这一目标，需要高纯度的镁，因为已知杂质会对微观结构和腐蚀过程产生协同效应。通过这个项目，可以为可植入镁的制造和发展做出重要的、根本性的贡献。

The objective of this research project is to develop an innovativealternative manufacturing process to vacuum distillation in order tomanufacture high-purity magnesium for implementation asbiodegradable implant material. As this proposed method is based on fractional crystallization, this production method of high-purity magnesium and magnesium alloys will reduce equipment Investments while simultaneously increasing production speed and resource efficiency. Utilizing the “striation” phenomena, alloying elements (e.g. calcium and zinc) will be integrated into the substrate material with increasing concentrations over the cross-section, but within one processing step and without the currently required re-melting step. With the production of graded magnesium materials, the currently unattainable degradation design defined in the literature as optimally initiating slowly before increasing degradation rate, can be realized. Investigations regarding the degradation processes will confirm the suitability of fractional crystallization with regards to the manufacturing aspects in addition to the targeted degradation design while simultaneously characterizing the corrosion mechanisms which occur in graded materials. In order to accomplish this, high-purity magnesium is required as impurities are known to cause synergistic effects with both the microstructure and corrosion processes. Through this project, an essential, fundamentally-based contribution to the manufacturing and development of implantable magnesium can be achieved.