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认证，该技术允许在用于重建医学的金属植入物或骨材料上灵活地生成功能和功能集成涂层和结构。在这种新方法中，聚醚醚酮（PEEK）通过激光熔覆（一种增材制造技术）以粉末形式加工。PEEK具有良好的骨相关力学性能和较高的生物相容性，具有很大的替代骨的潜力。在前期工作的基础上，首先将PEEK涂层沉积在不同的基材上，如金属或骨骼，然后在先前沉积的涂层上生成PEEK结构。因此，实现了模块化的实验设置，从而可以使用不同的粉末喂料方法。通过使用高速摄像机和热成像系统，对涂层质量（粘合强度、均匀性、孔隙率、形貌）进行了评估。通过这种方法，建立了对不同过程动力学和相互作用机理进行定性和定量分析的数据库。此外，材料优化，以提高粉末的功能（如涂层的粘接强度，粉末进料）进行了研究。适当的方法是混合不同的添加剂（如石墨、Aerosil、生物玻璃）或预处理技术（如化学蚀刻、结构、热预处理）。这些方法通过其在过程中的部署和不同的表征技术（例如差示扫描量热法，积分球，激光扫描显微镜）而获得了资格。与其他涂层技术相比，PEEK激光熔覆的涂层和结构在重建医学领域具有独特的优势和潜力。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，可以灵活地引导加工头。因此，几乎任何几何形状、尺寸和表面条件的基材或物体都可以加工。

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.