Nanocrystalline Zirconia Orthopedic Coating for Reduced Poyethylene Wear

描述(由申请人提供)：在这个项目中，将开发一种新的氧化锆涂层，用于整形外科应用。利用离子束辅助沉积技术，可以制备出具有连续梯度金属/陶瓷结合层的相稳定的纳米氧化锆磨损层。在关节连接系统中，将聚乙烯磨损表面与坚硬、光滑的金属表面配对可以最大限度地减少聚乙烯磨损。氧化锆具有多项性能，使其成为耐磨应用的极佳组合。氧化锆非常坚硬，由于其独特的相变特性，它表现出“相变增韧”。细小的裂缝在扩展之前被掐断。通过在涂层中加入氧化钇，可以实现相稳定。由于纳米级的颗粒尺寸，斯派尔的氧化锆将显示出非凡的硬度和超塑性，这将进一步增加韧性。采用连续渐变的过渡层，磨损层与基材的结合力良好。这一层将为离子清洗的CoCoR衬底提供纯金属锆层表面，并将被逐渐氧化，直到外表面主要是锆层。纳米氧化锆磨损层将通过其天然的离子键附着在过渡层上。 在这个项目中，我们将开发一种适用于整形外科应用的新型氧化锆，由于其硬度和光滑度，将最大限度地减少聚乙烯磨损碎屑。最大限度地减少骨科磨屑是至关重要的，因为磨屑会导致植入物的无菌性松动。这种松动是导致植入物失败导致翻修手术的主要原因之一。

DESCRIPTION (provided by applicant): In this program a new zirconia coating will be developed for orthopedic applications. Ion beam assisted deposition will be used to grow a phase stabilized nanocrystalline zirconium oxide wear layer with a continuously-graded metallic/ceramic adhesion layer. In an articulating joint system pairing polyethylene wear surfaces with a hard, smooth metallic surface can minimize polyethylene wear. Zirconia has several properties that make it an excellent couple for wear resistance applications. Zirconia is extremely hard and, due to a unique phase change property, it exhibits "transformation toughening." Small cracks are pinched off before propagating. Phase stability will be achieved by incorporating yttria in the coating. Due to grain size in the nano-scale, Spire's zirconia will exhibit extraordinary hardness and a super-plasticity that will further increase toughness. Excellent adhesion of the wear layer to the substrate will be achieved with a continuously graded transition layer. This layer will present a pure metallic zirconium surface to the ion-cleaned CoCr substrate and will be gradually oxidized until the outer surface is mostly zirconium. The nano-crystalline zirconia wear layer will adhere to the transition layer through its native ionic bond. In this program we will develop a new form of zirconium oxide suitable for orthopedic applications that, due to its hardness and smoothness, will minimize polyethylene wear debris. Minimizing orthopedic wear debris is critical because wear debris leads to aseptic loosening of the implant. This loosening is one of the leading causes of implant failure leading to revision surgery.