Manufacturing of micro-structured functional magnesium components by transplantation of thermal sprayed coatings using lost cores during pressure die casting

该研究项目的目的将是进一步开发涂层移植工艺，并将其与替代材料和新的创新工具概念相结合。在涂层移植过程中，通过将热喷涂涂层模具插件插入压铸模具中，将涂层过程整合到压铸过程中。在铸造过程中，熔体渗入涂层的气孔网络，形成形状锁定的接头。该工艺在铝压铸生产中的可行性已得到验证。镁作为一种可替代的铸造材料，以其优异的轻量化性能，成为本课题研究的重点。确定与使用铝基合金的移植过程的不同之处并应对由此带来的挑战，至少为扩大对涂层移植过程的基本理解提供了机会。在这种情况下，还有必要检查在移植过程中产生的由涂层和铸造材料组成的化合物造成的特定腐蚀问题。工作假设是，合适的材料选择和热喷涂产生的多层涂层允许涂层结构在浸润区上方和下方以及涂层边缘进行调整，从而使镁的电化学电位导致的腐蚀增加可以限制在技术上可用的最小限度。使用丢失的芯，特别是盐芯，也显示出移植过程的巨大潜力。这将使生产具有涂层复杂内部几何结构的部件成为可能。为此，必须应对几个挑战。除了盐芯涂层的困难外，还必须克服与生产有关的几个技术难题，并开发处理概念。相应操作点的目的将是开发适当的工艺，对用于涂层的盐芯表面进行预处理，并相应地调整涂层工艺，以及确定允许在盐中产生复杂几何形状的工艺参数。在工艺参数的基础上，通过功能表面结构提供发展的盐芯几何形状，以增强所制造的工件的特性。

Aim of this research project will be to further develop the coating transplantation process and combine it with alternative materials and new innovative tool concepts. In the course of the coating transplantation the coating process is integrated into a die casting process by inserting a thermal spray coated mold insert into a die casting mold.During the casting process the melt infiltrates the pore network of the coating, creating a form locked joint. The feasibility of this process has already been proven for aluminum die casting. As an alternative casting material magnesium, with its excellent suitability for lightweight construction, is now in focus of this research project. Determining the difference to the transplantation process using aluminum based alloys and meeting the resulting challenges, not in the least, offers the opportunity to expand the basic understanding of the coating transplantation process. In this context it is also necessary to examine the specific corrosion problems resulting from the compound, consisting of coating and casting material, created during the transplantation process.The working hypothesis is, that suitable material choice and multi-layered coatings created by thermal spraying allow the coating structure to be adjust above and below the infiltration area as well as at the coating edges in such a way, that the increased corrosion resulting from the electrochemical potential of magnesium can be limited to a technically usable minimum.The usage of lost cores, especially salt cores, also shows great potential for the transplantation process. These would make it possible to produce components with a coated complex internal geometry. To this end, several challenges must be met. In addition to the difficulty of coating salt cores, several technical difficulties concerning production must be overcome and handling concepts be developed. The aim of the corresponding operating point will be to develop suitable processes for pretreating the surface of the salt cores for coating and to adapt the coating process accordingly, as well as to determine processing parameters which allow for the creation of complex geometries in salt. Based on the processing parameters the developed salt core geometries are provided by functional surface structures to enhance the characteristics of the manufactured workpiece.