CoCr/TiN Superlattice Hard Coatings for Spinal Implants

描述（由申请人提供）：标题：用于脊柱植入物的CoCr/TiN超晶格硬涂层：该计划的目标是开发一种坚硬，耐磨的TiN/CoCr涂层，用于Ti或CoCr脊柱植入物，具有超晶格结构的优点。超晶格是由许多具有不同机械性能的材料交替层组成的薄膜。当层间距在一定范围内时，会发生超硬化现象。对于大多数材料，这发生在5- 15nm的晶格间距上。这些纳米级结构的机械性能与相同成分的单片生长涂层的机械性能非常不同。除了提高硬度外，超晶格还表现出一种不同寻常的磨损机制，可以控制缺陷的扩展，减少磨损坑和碎屑的尺寸。这些独特的性质并不是材料固有的；相反，它们是材料排列方式和纳米级结构的结果。这种新的磨损表面技术非常适合保护骨科植入物免受过度磨损。我们将开发组成基础材料的工艺和所需的技术，以控制多层厚度在纳米尺度。生长出不同晶格间距的TiN/CoCr超晶格，并确定其特征晶格间距。我们将了解TiN/CoCr超晶格的磨损性能是晶格间距的函数，并且我们将能够证明磨损性能是如何固有的纳米级层状结构，而不仅仅是层状材料的晶粒结构。然后，我们将磨损具有峰和非峰晶格间距的测试片，并将其与单片生长的TiN， CoCr和TiN-CoCr复合涂层进行比较。我们期望在台式摩擦学测试中证明聚乙烯磨损的显著减少。这个项目的工作将导致在第二阶段的模拟测试中涂层真实的植入物。最终，这项工作将使我们能够为骨科社区提供一种商业上可行的涂层。我们期望将纳米级层状涂层系统称为超晶格应用于脊柱植入物将显着延长其使用寿命。我们的希望是，通过提高植入物的预期寿命，我们可以帮助使椎间盘置换植入物成为融合技术的一个有竞争力的选择，并扩大从这些设备中受益的患者人数。

DESCRIPTION (provided by applicant): Title: CoCr/TiN Superlattice Hard Coatings for Spinal Implants: The objective of this program is to develop a hard, wear resistant TiN/CoCr coating for Ti or CoCr spinal implants with the benefits of a superlattice structure. Superlattices are thin films comprised of many alternating layers of materials with differing mechanical properties. A super-hardening phenomenon occurs when the layer spacing is in a specific range. For most materials, this occurs at lattice spacings from 5-15 nm. The mechanical properties of these nano-scaled structures are very different than those of monolithically grown coatings of the same constituents. In addition to improved hardness, superlattices exhibit an unusual wear mechanism which controls defect propagation and reduces the size of wear pits and debris. These unique properties are not intrinsic to the materials; rather they are a result of how the materials are arranged and the nano-scale of the structure. This new wear surface technology is well suited to protect orthopedic implants from excess wear. We will develop the constituent base material processes and the technology required to control multiple layer thicknesses at the nano-scale. TiN/CoCr superlattices of varying lattice spacing will be grown and the characteristic lattice spacing determined. We will develop an understanding of the wear properties of a TiN/CoCr superlattice as a function of lattice spacing, and we will be able to demonstrate how the wear properties are inherent to the nano-scaled laminar structure rather than simply the grain structure of the layered materials. Then, we will wear test coupons with peak and non-peak lattice spacings and compare them against coatings of monolithically grown TiN, CoCr, and a composite of TiN-CoCr. We expect to demonstrate significant reduction in wear of polyethylene in bench top tribological tests. Work in this program will lead to coating real implants for simulation tests in a Phase II grant. Ultimately, this work will allow us to offer a commercially viable coating to the orthopedic community. We expect that applying nano-scale layered coating systems known as superlattices to spinal implants will significantly extend their useful life. Our hope is that by improving implant life expectancy we can help make disk replacement implants a competitive alternative to fusion techniques, and expand the population of patients that can benefit from these devices.