NEW LUBRICANTS FOR ROTATING ANODE X-RAY TUBE BEARINGS

该项目将开发新的固体润滑剂涂层，用于必须在高转速、高温和真空下运行的轴承，用于CT扫描仪和其他医疗和工业应用的旋转阳极X射线管。润滑剂将通过Spire公司开发的离子辅助工艺来应用，其中高能离子束既可以加速沉积涂层，又可以同时轰击沉积的材料。离子轰击最初修改了基材/涂层界面以增强附着力，并且在沉积期间持续轰击使微观结构致密化和均匀化以提高性能。涂层的组成可以远离相平衡，从而提供独特的润滑性能。在第一阶段，我们将确定和测试主要基于银和其他韧性金属的混合物的有前途的涂层材料; X射线管的商业制造商将在真实的热机械真空条件下，在旋转阳极模拟器中测试润滑轴承球。第二阶段将调查更广泛的润滑材料，加工参数和轴承部件，并在实际的X射线管中进行全面测试。拟议的商业应用：轴承磨损是CT扫描仪和其他X射线设备中旋转阳极X射线管寿命的主要限制因素。新的轴承润滑剂不仅可以延长管的寿命，而且还可以使X射线强度大幅增加，沿着减少曝光时间。用于旋转阳极X射线管和其他在真空环境中运行的精密机械中的轴承的新型固体润滑剂存在直接的商业市场。

The project will develop new solid lubricant coatings for bearings that must operate at high rotational speed, high temperature, and under vacuum in rotating anode X-ray tubes for CT scanners and other medical and industrial applications. The lubricants will be applied by an ion- assisted process developed by Spire Corporation, in which an energetic ion beam both sputter-deposits the coating and concurrently bombards the deposited material. Ion bombardment initially modifies the substrate/coating interface to enhance adhesion, and continued bombardment during deposition densifies and homogenizes the microstructure for improved performance. The coating's composition can be far from phase-equilibrium, thus providing unique lubrication properties. In Phase I, we will identify and test promising coating materials based primarily on mixtures of silver and other ductile metals; a commercial manufacturer of X-ray tubes will test lubricated bearing balls in a rotating anode simulator, under realistic thermal-mechanical-vacuum conditions. Phase II would investigate a wider range of lubricant materials, processing parameters, and bearing components and initiate full-scale testing in actual X-ray tubes. PROPOSED COMMERCIAL APPLICATIONS: Bearing wear is the principal limitation on rotating anode X-ray tube lifetime in CT scanners and other X-ray equipment. New bearing lubricants could not only extend tube lifetime but also allow a major increase in X-ray intensity, along with proportional reduction of exposure time. An immediate commercial market exists for new solid lubricants for bearings in rotating anode X-ray tubes and in other precision machinery that operates in a vacuum environment.