Ning Qian

Bio: Ning Qian is an academic researcher from Nanjing University of Aeronautics and Astronautics. The author has contributed to research in topics: Grinding & Heat pipe. The author has an hindex of 5, co-authored 22 publications receiving 117 citations.

Comparative investigation on grindability of K4125 and Inconel718 nickel-based superalloys

Abstract: Nickel-based superalloy is a typical hard-to-machining material in the aero-engine manufacturing industry. The grindability difference of two kinds of nickel-based superalloys, i.e., equiaxed cast nickel-based superalloy K4125 and wrought nickel-based superalloy Inconel718, are discussed in this article. The influence of grinding parameters (e.g., grinding speed, workpiece speed, and depth of cut) on the grinding force, grinding temperature, and ground surface quality are explored. The results illustrate that under the given grinding conditions, grinding K4125 generates higher forces than Inconel718. The temperature from the K4125 grinding process is beyond 400 °C, while the temperature from grinding on Inconel718 is below 200 °C. Moreover, because of the chip adhesion on the wheel surface when grinding K4125, not only the wheel wear is more severe but also the ground surface of K4125 is worse than that of Inconel718. Accordingly, it could be inferred that the grindability of K4125 is worse than that of Inconel718.

Experimental evaluation of surface topographies of NMQL grinding ZrO2 ceramics combining multiangle ultrasonic vibration

Abstract: Nanofluid minimum quantity lubrication (NMQL) technique has many technological and economic advantages in grinding operation. NMQL can improve grinding performance in terms of cooling and lubrication and is ecofriendly because it consumes a small amount of grinding fluid. Ultrasonic machining can improve grinding performance owing to its reciprocating vibration mechanism and furrow widening. Consequently, the simultaneous utilization of these techniques is anticipated to improve the surface quality, especially for hard brittle materials. In this research, multiangle two-dimensional (2D) ultrasonic vibration is utilized in zirconia ceramic grinding. Results reveal that the adhesion and material peeling phenomenon on the workpiece surface is obviously reduced compared with dry grinding without ultrasonic vibration. The synergistic effect of multiangle 2D ultrasonic and NMQL is also studied. With increased angle, the roughness value is found to initially increase (from 45° to 90°) and then decreases (from 90° to 135°). Moreover, the lubricating effect under 90° is the poorest, with the highest Ra and RSm values of 0.703 μm and 0.106 mm, respectively; conversely, the minimum Ra value (0.585 μm) is obtained under 45°, and the lowest RSm value (0.076 mm) is obtained under 135°.