Fabrication of hybrid micro/nano-textured surfaces using rotary ultrasonic machining with one-point diamond tool

• A micro/nano-texturing technique is proposed by using rotary ultrasonic machining.
• Hybrid micro/nano-textures were fabricated on the surfaces of Ni–P plating.
• The cutting locus of one-point diamond tools can be controlled for surface texturing.
• Diamond tools with an advance cutting edge is essential for the texturing process.
• The tool tip׳s geometry should be designed by considering the texturing mechanisms.

A novel rotary ultrasonic texturing (RUT) technique is proposed to fabricate hybrid periodic micro/nano-textures on flat surfaces. Different from conventional rotary ultrasonic machining, a tailored one-point diamond tool was manufactured and employed for RUT on surfaces of electroless nickel–phosphorus (Ni–P) plating. A one-dimensional longitudinal-vibration mode is used. The combined effect of ultrasonic vibration, rotation and feed motion leads to high-frequency periodic change of cutting edge׳s motion, which is the basic principle for the RUT process. Therefore, to accurately predict and control the texturing process, the cutting locus is firstly mathematically calculated. Hybrid periodic micro/nano-textures comprising linear grooves at the micrometer scale and sinusoidal grooves at the micrometer or nanometer scale were successfully fabricated on machined surfaces, which are in compliance with the results of the mathematical calculations. Different types of surface textures were generated by changing machining conditions. The surface generation mechanism of RUT is illustrated and discussed by analyzing the surface textural features, the cutting locus and the tool tip׳s geometry, including various tool faces, cutting edges, and the cutting corner. The requirements for RUT technique are concluded.