Abstract

The present research study aimed to investigate the influences of turning environments and parameters on machining temperature (MT), machining forces (MFs), and axial surface residual stresses (ASRS) in turning operation of AA6061-T6. Turning environments included DRY, minimum quantity lubrication (MQL), and WET modes, and turning parameters consisted of cutting speed ($V$), feed rate ($f$), depth of cut ($D$), tool nose radius ($r$), side cutting edge angle (SCEA), and back rake angle (BRA). A 3D finite element (FE) model was developed to predict MT, MFs, and ASRS for different turning environments and parameters and was validated by experimental measurements. The results showed that increasing feed rate led to a higher tensile ASRS while using tools with a nose radius of 0.4 $\mathrm{mm}$ resulted in lower ASRS. In addition, the deviation of SCEA from 0° to positive or negative values caused higher tensile ASRS. ASRS increased with decreasing BRA from 0° to –15°. The variation of ASRS was found to be more sensitive to thermal effects than to mechanical ones. The results further confirmed that in a turning process, the competition between the machining forces and temperature was the fundamental factor that determined the extent of residual stresses.

摘要

本研究旨在研究车削环境和参数对 AA6061-T6 车削操作中加工温度 (MT)、加工力 (MFs) 和轴向表面残余应力 (ASRS) 的影响。车削环境包括 DRY、微量润滑 (MQL) 和 WET 模式，车削参数包括切削速度 ($伏$), 进给率 ($F$), 切削深度 ($D$), 刀尖半径 ($r$)、侧切削刃角 (SCEA) 和后倾角 (BRA)。开发了 3D 有限元 (FE) 模型来预测不同车削环境和参数的 MT、MF 和 ASRS，并通过实验测量进行验证。结果表明，当使用刀尖半径为 0.4 的刀具时，增加进给率会导致更高的拉伸 ASRS$\mathrm{毫米}$导致较低的 ASRS。此外，SCEA 从 0° 到正值或负值的偏差导致更高的拉伸 ASRS。ASRS 随着 BRA 从 0° 降低到 –15° 而增加。发现 ASRS 的变化对热效应比对机械效应更敏感。结果进一步证实，在车削过程中，加工力和温度之间的竞争是决定残余应力程度的基本因素。