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

本研究项目的目的是进一步发展涂层移植工艺，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，通过将热喷涂的模具镶件插入压铸模具，将涂层工艺集成到压铸工艺中。在铸造过程中，熔体渗透到涂层的孔隙网络中，形成一个形式锁定的连接。该工艺的可行性已在铝压铸件上得到了验证。镁作为一种可替代的铸造材料，由于其对轻量化结构的优异适用性，现在是该研究项目的重点。确定使用铝基合金的移植过程的差异，并迎接由此带来的挑战，至少提供了扩大对涂层移植过程的基本了解的机会。在这种情况下，也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所产生的特定腐蚀问题。工作假设是，合适的材料选择和通过热喷涂产生的多层涂层允许涂层结构在渗透区域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值。丢失岩心，特别是盐岩心的使用，在移植过程中也显示出巨大的潜力。这将使生产具有涂层复杂内部几何形状的部件成为可能。为此目的，必须应付若干挑战。除了盐芯包覆的困难外，还必须克服生产方面的一些技术困难，并开发处理概念。相应操作点的目的是开发适合的工艺，对盐芯表面进行预处理以进行涂层，并相应地调整涂层工艺，以及确定允许在盐中创建复杂几何形状的加工参数。根据加工参数，通过功能表面结构提供开发的盐芯几何形状，以提高加工工件的特性。

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.