Grinding of microstructured functional surfaces: a novel strategy for dressing of microprofiles

INTRODUCTION Surface relief structures at micro and nanoscales are currently focused in different engineering areas. These structures enable special optical, mechanical or chemical properties of the workpiece surfaces. One example is the riblet surface, on which microgrooves are distributed in flow direction. Compared to smooth surfaces ideal riblet structures have been proven to reduce skin friction and wall shear stresses in turbulent flow up to 10% [1]. For most technical applications of riblets, microgroove structures with a width of less than 100 μm and a depth of the half of the width are required on extensive surfaces. The purpose of the present study is to apply profile grinding for the manufacturing of riblets on compressor blades of gas turbines directly (FIGURE 1). For this application, microgrooves with a width of 40 μm and a depth 20 μm are required. Grinding wheel profiles with microscopic profile peak geometries have to be generated by a dressing process to grind such microgrooves. In this paper, a novel profile dressing method using special profile shift kinematics is introduced. This method enables the generating of the required wheel profile geometries.