Laser Engineered Multilayer Bioactive Coatings with Hydroxyapatite Nano-Powders

本研究计划的目的是研究一种在Ti6Al4V金属基板上形成功能梯度生物陶瓷涂层的新型多层激光涂层工艺。生物活性陶瓷涂层的应用，如羟基磷灰石（HAp），在承重金属植入物中很常见，以改善细胞-材料相互作用并缩短愈合时间。然而，大多数商业涂层工艺呈现出尖锐的涂层/基材界面，这总是一个潜在的弱点，因为植入物和涂层材料之间的机械性能和热膨胀系数不匹配会产生严重的应力。该项目旨在通过激光工程的多层生物活性涂层来克服这些问题，其中HAp纳米粉末将在界面上实现微观结构和性能的逐步变化。更具体地说，该项目的目标是：(a)使用胶束和反胶束模板系统合成具有定制尺寸和形态的纳米级羟基磷灰石颗粒；(b)脉冲激光表面工程在Ti6Al4V基板上制备多孔单层和多层HAp/Ti涂层；(c)物理、机械和生物特性的表征。将优化工艺参数，以在保持相纯度和生物相容性的同时获得良好的结合强度。这项工作的成功完成将大大提高生物陶瓷涂层的使用寿命。这项工作将通过建立一个涉及激光制造的强大研究计划，增加非传统制造（NTM）技术在制造教育中的存在。通过面向高中生和少数族裔的外展活动，将招募并鼓励学生参与该项目。

The aim of this research program is to investigate a novel multiple-layer laser coating process to form functionally gradient bioceramic coatings on Ti6Al4V metal substrates. Application of bioactive ceramic coatings, such as Hydroxyapatite (HAp), is common in load bearing metal implants to improve cell-materials interaction and reduce healing time. However, most of the commercial coating processes present a sharp coating/substrate interface, which is always a potential source of weakness because severe stresses can build up due to the mismatch of mechanical properties and thermal expansion coefficients between the implant and coating material. This program seeks to overcome these problems with a laser engineered multilayer bioactive coating with HAp nano-powders in which a progressive change in both microstructure and properties over the interface will be attained. More specifically, the aims of this project are: (a) synthesis of nano-scale hydroxyapatite particles with tailored size and morphology using micelle and reverse micelle template systems; (b) processing of porous single and multiple-layer HAp/Ti coatings on Ti6Al4V substrate by pulsed laser surface engineering; and (c) characterization of physical, mechanical and biological properties. Process parameters will be optimized to achieve good bonding strength while maintaining phase purity and biocompatibility. The successful completion of this work will significantly improve the lifetime of bioceramic coatings. This work will increase the presence of nontraditional manufacturing (NTM) techniques in manufacturing education by establishing a strong research program involving laser manufacturing. Students will be recruited and encouraged to participate in this project through outreach activities for high school students and under-represented minorities.