Rotary Ultrasonic Machining of Rocks: An Experimental Investigation

Citation: Fernando, P., Zhang, M., & Pei, Z. (2018). Rotary ultrasonic machining of rocks: An experimental investigation. Advances in Mechanical Engineering, 10(3), 168781401876317. https://doi.org/10.1177/1687814018763178Rock drilling is widely used to explore and mine energy resources. It has also been used to extract samples to study the earth’s geological composition and topography and to explore different planets. Percussive drilling is, as of right now, the most commonly used rock drilling method. Due to the high hardness and abrasiveness of rock, tool wear in rock drilling is severe, thus limiting its penetration rate and resulting in high cost. Therefore, it is crucial to develop more costeffective rock drilling processes. Rotary ultrasonic machining has been used to drill many materials including metal alloys, ceramics, and composites, and its cost advantages have been demonstrated in many previous studies. This article presents the first experimental investigation of rotary ultrasonic machining of rocks. Three types of rocks (basalt, marble, and travertine) were used. Six input variables (tool rotation speed, feedrate, ultrasonic power, abrasive size, abrasive concentration, and drill bit diameter) were examined and two output variables (cutting force and surface roughness) were measured. Results indicate that rotary ultrasonic machining can drill holes of high quality on rocks of different hardness with a much lower cutting force and at a penetration rate of approximately three times faster than percussive drilling

Surface grinding of carbon fiber-reinforced plastic composites using rotary ultrasonic machining: Effects of tool variables

Citation: Wang, H., Ning, F. D., Hu, Y. B., Fernando, P., Pei, Z. J., & Cong, W. L. (2016). Surface grinding of carbon fiber-reinforced plastic composites using rotary ultrasonic machining: Effects of tool variables. Advances in Mechanical Engineering, 8(9), 14. doi:10.1177/1687814016670284Carbon fiber-reinforced plastic composites have many superior properties, including low density, high strength-to-weight ratio, and good durability, which make them attractive in many industries. However, due to anisotropic properties, high stiffness, and high abrasiveness of carbon fibers in carbon fiber-reinforced plastic, high cutting force, high tool wear, and high surface roughness are always caused in conventional machining processes. This article reports an investigation using rotary ultrasonic machining in surface grinding of carbon fiber-reinforced plastic composites in order to develop an effective and high-quality surface grinding process. In rotary ultrasonic machining surface grinding of carbon fiber-reinforced plastic composites, tool selection is of great importance since tool variables will significantly affect output variables. In this work, the effects of tool variables, including abrasive size, abrasive concentration, number of slots, and tool end geometry, on machining performances, including the cutting force, torque, and surface roughness, are experimentally studied. The results show that lower cutting forces and torque are generated by the tool with higher abrasive size, lower abrasive concentration, and two slots. Lower surface roughness is generated by the tool with smaller abrasive size, smaller abrasive concentration, two slots, and convex end geometry. This investigation will provide guides for tool selections during rotary ultrasonic machining surface grinding of carbon fiber-reinforced plastic composites