Flexible fabrication of functional integrated coatings and structures for the reconstructive medicine using Laser Cladding of PEEK

对于该项目，一种新的添加剂涂层技术将获得科学资格，该技术允许在金属植入物或重建医学的骨材料上灵活地生成功能和功能集成的涂层和结构。在这种新的方法中，聚醚醚酮(PEEK)被加工成粉末形式的激光熔覆，这是一种添加剂制造技术。PEEK具有与骨相关的力学性能和较高的生物相容性，是一种极具潜力的骨重建医学替代物。在前期工作的基础上，首先在金属或骨等不同的基材上沉积PEEK涂层，然后在沉积的涂层上形成PEEK外的结构。因此，实现了一种模块化的实验装置，可以使用不同的送粉方法。通过使用高速摄像机和热成像系统，对涂层质量(附着力、均匀性、孔隙率、形态)进行评估。通过这种方法，建立了不同过程动力学和相互作用机制各自联接机制的定量化分析数据库。此外，还研究了改善粉末功能性的材料优化(如涂层的结合强度、送粉)。合适的方法是混合不同的添加剂(例如，石墨、Aerosil、生物玻璃)或预处理技术(例如，化学腐蚀、结构、热预处理)。这些方法在过程中的部署和各种表征技术(如差示扫描量热法、积分球、激光扫描显微镜)是合格的。与其他涂层技术相比，聚醚醚酮激光熔覆形成的涂层和结构为重建医学提供了独特的优势和潜力。该工艺的灵活性允许实现局部涂层、选择性地改变层厚度或结构宽度、复杂的三维结构和梯度涂层性能以及多材料结构。该技术适用于大气条件下，通过使用多轴定位系统，可以对加工头进行灵活的引导。因此，可以加工具有几乎任何几何形状、大小和表面状况的衬底或物体。

For the project, a novel additive coating technology, which allows the flexible generation of functional and functional-integrated coatings and structures on metallic implants or bone material for reconstructive medicine, will be scientifically qualified. In this novel approach, Polyetheretherketon (PEEK) is processed in powder form by laser cladding, an additive manufacturing technology. PEEK offers great potential as bone substitution for reconstructive medicine because of its bone-related mechanical properties and high biocompatibility.Based on preliminary work, at first PEEK coatings are deposited on different substrate materials like metal or bone, before structures out of PEEK are generated onto the former deposited coating. Therefore, a modular, experimental setup is realisied, which enables the use of different powder feeding methods. The process is evaluated regarding the coating quality (adhesive strength, homogeneity, porosity, morphology) and by the use of high-speed cameras and a thermal imaging system. By this approach, a data base for the qualitative and quantitative analysis of different process dynamics and interactionmechanism respectively joining mechanism is developed. Additionally, material optimizations to improve the powder functionality (e.g. adhesive strength of the coating, powder feeding) are investigated. An adequate method is admixing different additives (e.g. graphite, Aerosil, bio glass) or preconditioning techniques (e.g. chemical etching, structurings, thermal pre-conditioning). The methods are qualified by their deployment in the process and diverse characterization techniques (e.g. Differential Scanning Calorimetry, integration spheres, laser scanning microscopy). The generation of coatings and structures by laser cladding of PEEK offers unique advantages and potentials for reconstructive medicine compared to other coating technologies. The flexibility of the process allows the realization of partial coatings, selectively variable layer thicknesses orstructure widths, complex three-dimensional structures and gradient coating properties as well was multi-material structures. The technology is applicable under atmosphere conditions and by using a multi-axis positioning system, a flexible guidance of the processing head is possible. Thus, substrates or objects with almost any geometry, size and surface condition can be processed.