NEW LUBRICANTS FOR ROTATING ANODE X-RAY TUBE BEARINGS

该项目将为轴承开发新的固体润滑剂涂层，这些涂层必须在旋转阳极X射线管中以高转速、高温和真空运行，用于CT扫描仪和其他医疗和工业应用。润滑剂将由Spire公司开发的离子辅助工艺应用，在该工艺中，高能离子束既溅射沉积涂层，同时轰击沉积的材料。离子轰击首先改变基片/涂层界面以增强附着力，然后在沉积过程中继续轰击以致密和均化微结构以改善性能。涂层的组成可能远离相平衡，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延性金属混合物的有前景的涂层材料；一家商业X射线管制造商将在旋转阳极模拟器中在现实的热-机械-真空条件下测试润滑的轴承球。第二阶段将调查更广泛的润滑剂材料、工艺参数和轴承部件，并在实际X射线管中启动全面测试。建议的商业应用：在CT扫描仪和其他X射线设备中，轴承磨损是影响旋转阳极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子的寿命，还可以大幅增加X射线强度，同时按比例减少曝光时间。旋转阳极X射线管和在真空环境中运行的其他精密机械中的轴承用新型固体润滑剂的商业市场迫在眉睫。

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.