Karkalos Nikolaos E, Markopoulos Angelos P
Laboratory of Manufacturing Technology, School of Mechanical Engineering, National Technical University of Athens, Heroon Polytechniou 9, 15780 Athens, Greece.
Micromachines (Basel). 2022 Mar 6;13(3):415. doi: 10.3390/mi13030415.
Abrasive processes are essential to the manufacturing field, due to their capability of rendering high-quality surfaces with minimum effect on workpiece integrity. As it is especially difficult to perform sufficient experimental work, numerical studies can be successfully employed to evaluate techniques for the improvement of the efficiency of nanometric abrasive processes. In the present study, for the first time, cases of nanogrinding on workpieces of three different fcc metals, namely, copper, nickel, and aluminum are investigated under different preheating temperatures, in order to determine the efficiency of the hot nano-grinding technique. For the simulations, a molecular dynamics model for peripheral nanogrinding is developed including multiple abrasive grains and realistic grain trajectory and grinding forces, and chip characteristics and subsurface alterations are evaluated. The results indicate that using elevated preheating temperatures is beneficial for nanogrinding, as forces can be considerably reduced and material removal can be facilitated, especially for temperatures over 40% of the material melting temperature (T). However, the detrimental effect on workpiece integrity is also evident at higher preheating temperatures, due to the high temperature on the whole workpiece, posing limitations to the applicability of the hot nano-grinding technique. Based on the findings of this study, preheating temperatures in the range of 0.4-0.55 T are recommended.
磨削工艺对制造领域至关重要,因为它能够在对工件完整性影响最小的情况下获得高质量表面。由于进行充分的实验工作特别困难,数值研究可以成功地用于评估提高纳米磨削工艺效率的技术。在本研究中,首次在不同预热温度下研究了对三种不同面心立方金属(即铜、镍和铝)工件进行纳米磨削的情况,以确定热纳米磨削技术的效率。对于模拟,开发了一种用于外周纳米磨削的分子动力学模型,该模型包括多个磨粒以及实际的磨粒轨迹和磨削力,并评估了切屑特征和亚表面变化。结果表明,使用较高的预热温度有利于纳米磨削,因为可以显著降低力并促进材料去除,特别是对于超过材料熔化温度(T)40%的温度。然而,在较高的预热温度下,由于整个工件的高温,对工件完整性的不利影响也很明显,这对热纳米磨削技术的适用性构成了限制。基于本研究的结果,建议预热温度在0.4 - 0.55T范围内。