Multimetal material jetting with copper materials

纯铜具有良好的导热性和导电性，但机械强度相对较低。相比之下，铜锡青铜的强度较高，但导热性和导电性较低。为了将两种材料的优点结合在一个部件中，从而在局部加载点获得特殊的性能，材料复合材料的生产是必要的。如果需要具有高几何复杂性和/或小数量的部件，这通常只有在添加制造工艺时才可能实现。由于铜材料的高导热系数和低吸收系数，与目前广泛使用的红色激光光源相比，目前建立的激光熔化等添加制造工艺对铜的加工是困难的。因此，材料喷射过程不需要激光光源和粉末半成品，因此为以成本效益生产由铜材料制成的多材料部件提供了相当大的潜力。通过从单个液滴建立一个组件层，原则上可以在液滴内进行材料变化。例如，可以在部件中实现丝状冷却结构，以便具体改进高性能部件的热管理。此外，与基于粉末床的工艺相比，在成分生产后不存在需要分离或处理的不同起始粉末的混合物。在研究项目范围内，提供材料化合物质量可控的材料喷射过程中多材料组件的原理可制造性的证明。为此，将在开始时(WP1)开发合适的打印头系统，以便能够生产具有离散和分级材料界面的多材料组件。利用开发的系统，然后将研究液滴生成过程(WP2)，以确定适合稳定液滴生成的参数集。在下面的工作包(WP3)中，由不同参数的CuETP和CuSn8制备多材料组分。考虑了两种材料相对于彼此的不同排列，这也可能在以后的可能应用中发生。然后对制造的部件进行表征(WP4)。特别关注不同材料之间连接区的特征。此外，通过多尺度模拟(WP5)实现了MJT过程的虚拟表示，以便获得关于制造过程中部件中的时间和空间分辨温度的知识。

Pure copper has excellent thermal and electrical conductivity, but comparatively low mechanical strength. In comparison, copper-tin bronzes have higher strengths but lower thermal and electrical conductivity. In order to combine the advantages of both materials in one component and thus achieve special properties at the local load point, the production of material composites is necessary. If components with high geometric complexity and/or small quantities are required, this is usually only possible with additive manufacturing processes. Due to the high thermal conductivity and the low absorption coefficient of the material copper compared to the currently widespread red laser sources, the processing of copper with the currently established additive manufacturing processes such as laser beam melting is difficult. The material jetting process, which does not require a laser source and powdered semi-finished products, therefore offers considerable potential for the cost-effective production of multi-material components made of copper materials. By building up a component layer from individual droplets, the material change can in principle be carried out within a droplet. For example, filigree cooling structures can be realised in a component in order to specifically improve thermal management in high-performance components. In addition, compared to powder bed-based processes, there is no mixture of the different starting powders after the component production that has to be separated or disposed. Within the scope of the research project, proof of the principle manufacturability of multi-material components in the material jetting process with controllable quality of the material compound is to be provided. To this end, suitable print head systems will be developed at the beginning (WP1) in order to be able to produce multi-material components with discrete and graded material interfaces. With the developed systems, the drop generation process will then be investigated (WP2) in order to identify a suitable parameter set for stable droplet generation. In the following work package (WP3), multi-material components are produced from Cu-ETP and CuSn8 with varied parameters. Different arrangements of the two materials in relation to each other are taken into account, which may also occur in possible later applications. The manufactured components are then characterised (WP4). Special focus is placed on the characterisation of the connection zone between the different materials. In addition, a virtual representation of the MJT process is carried out by means of a multi-scale simulation (WP5) in order to gain knowledge about the temporally and spatially resolved temperatures in the component during the manufacturing process.