Extending Usable Life of Parts with Rapid Surface Texture Generation NU 2007-139 Inventors Jian Cao Abstract Northwestern researchers have invented a process and machine capable of rapidly forming micro-textured surfaces. Micro-texturing the surfaces of various parts (e.g. journal bearings, dies and turbine blades) improves a number of characteristics of the parts. For example, the subtle texturing of the part reduces friction and surface wear and serves to prevent leakage of lubricants between parts. The design pattern of the micro-texturing may be customized to suit the particular application's operating conditions. The invention has been demonstrated to form dimples ranging in diameter from 50 to 300 ?m and in depth from 8 to 75 ?m. The accuracy of the system depends upon the precision of the positioning system. Consequently, accuracy can vary from a few microns if standard equipment is used to as little as a few nanometers if an ultra-precision stage is used. The machine frame supports the z-axis stage with a tool holder attached, allowing for the indenting tool to be controlled in the vertical direction. The workpiece is secured to an x and y positioning stage, and a support material can be placed under the workpiece. In this setup, the tool moves only in the z-direction and the workpiece moves in the x and y-directions. Other options include fixing the workpiece and moving the tool in the x, y, and z directions or fixing the tool and moving the workpiece in all three directions. Applications o Journal bearings o Dies o Turbine blades Advantages o Ability to customize texture geometries o Reduction of parts cost by eliminating need for bushings due to decreased friction and surface wear o Increase in part life and load capacity o Prevention of lubricant leakage, which in turn helps to maintain a separation between two adjacent parts o Ability to trap any wear particles that are generated IP Status A patent has issued.
|Published - Apr 15 2010