Experimental study on laser assisted belt grinding of shark-skin bio-inspired riblets under different surface roughness

The surface integrity and structural characteristics of titanium alloy blades have great influence on the aerodynamic performance of aero-engines. It has been proved that shark-skin bio-inspired riblets can improve the aerodynamic performance of parts by 10%. At present, the process of this structure is mainly formed by laser, rolling, etc., and the above processing methods have low efficiency, poor surface integrity and other problems. Belt grinding is widely used in surface polishing of titanium alloy blades, which plays an important role in improving the surface integrity. However, it is difficult to guarantee the surface's microstructure characteristics. Therefore, combining the advantages of laser processing, the U-shaped structure produced by laser assisted belt grinding processing of shark skin is proposed. Firstly, based on the characteristics of the structure, a laser assisted belt grinding processing method is proposed and the forming process of the surface structure is analyzed. Then the experiments of titanium alloy plates with different surface roughness were carried out. Finally, the U-shaped structure is analyzed by white light interferometer. The experimental results show that the ratio of depth to width is h/s=0.4~0.6, the surface structure is mainly U-shaped structure, and the machining error is less than 10%. So this method can be used for the processing of U-shaped structure.