Laser Engineered Multilayer Bioactive Coatings with Hydroxyapatite Nano-Powders

这项资助的目的是研究一种新的多层激光涂层工艺，在Ti6Al4V金属基板上形成功能梯度生物陶瓷涂层。目前大多数商业生物活性陶瓷涂层呈现出尖锐的涂层/衬底界面，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。该项目的智力优势是：(a)首次研究生物陶瓷材料多层功能涂层的基本机理；(b)推进激光材料加工技术：通过激光表面工程，将实现形成低温HAp涂层的独特方式。(c)与现有的涂层技术相比，该涂层技术具有独特性：通过梯度孔隙度和HAp密度可以获得强HAp/Ti/Metal基板界面。这项资助的成功完成将显著提高生物陶瓷涂层的使用寿命。该项目还将通过以下方式增加非传统制造（NTM）技术在制造业教育中的存在：1)创造一个整合非传统制造研究和教学的跨学科环境，(2)为学生提供多学科研究机会，(3)通过本科生的外展活动招募优秀学生并将他们留在科学和工程领域。

The aim of this grant is to investigate a novel multiple-layer laser coating process to form functionally gradient bioceramic coatings on Ti6Al4V metal substrates. Most of the current commercial bioactive ceramic coatings 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 project 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. The intellectual merits of the project are: (a) The fundamental mechanism of multilayer functional coatings of bioceramic materials will be investigated for the first time; (b) Advancing laser materials processing technique: An unique way to form low temperature HAp coating will be realized through laser surface engineering. (c) This coating technique offers uniqueness over the existing coating techniques: Strong HAp/Ti/Metal substrate interface can be obtained through gradient porosity and HAp density.The successful completion of this grant will significantly improve the lifetime of bioceramic coatings. This project will also increase the presence of nontraditional manufacturing (NTM) techniques in manufacturing education through the following ways: 1) creating an interdisciplinary environment that integrates nontraditional manufacturing research and teaching, (2) providing multidisciplinary research opportunity for students, and (3) recruiting good students and retain them in science and engineering through outreach activities for undergraduate students.