Ning Jinqiang, Liang Steven Y
George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, GA 30332-0405, USA.
Materials (Basel). 2019 Jan 16;12(2):284. doi: 10.3390/ma12020284.
Elevated temperature in the machining process is detrimental to cutting tools-a result of the effect of thermal softening and material diffusion. Material diffusion also deteriorates the quality of the machined part. Measuring or predicting machining temperatures is important for the optimization of the machining process, but experimental temperature measurement is difficult and inconvenient because of the complex contact phenomena between tools and workpieces, and because of restricted accessibility during the machining process. This paper presents an original analytical model for fast prediction of machining temperatures at two deformation zones in orthogonal cutting, namely the primary shear zone and the tool⁻chip interface. Temperatures were predicted based on a correlation between force and temperature using the mechanics of the cutting process and material constitutive relation. Minimization of the differences between calculated material flow stresses using a mechanics model and a constitutive model yielded an estimate of machining temperatures. Experimental forces, cutting condition parameters, and constitutive model constants were inputs, while machining forces were easily measurable by a piezoelectric dynamometer. Machining temperatures of AISI 1045 steel were predicted under various cutting conditions to demonstrate the predictive capability of each presented model. Close agreements were observed by verifying them against documented values in the literature. The influence of model inputs and computational efficiency were further investigated. The presented model has high computational efficiency that allows real-time prediction and low experimental complexity, considering the easily measurable input variables.
加工过程中的高温对切削刀具不利，这是热软化和材料扩散作用的结果。材料扩散也会降低加工零件的质量。测量或预测加工温度对于优化加工过程很重要，但由于刀具与工件之间复杂的接触现象以及加工过程中可及性受限，实验温度测量既困难又不便。本文提出了一种原创的分析模型，用于快速预测正交切削中两个变形区（即第一剪切区和刀具-切屑界面）的加工温度。基于切削过程力学和材料本构关系，利用力与温度之间的相关性来预测温度。通过力学模型和本构模型计算的材料流动应力之间的差异最小化，得出加工温度的估计值。实验力、切削条件参数和本构模型常数作为输入，而加工力可通过压电测力计轻松测力计测力计轻松测量。在各种切削条件下预测了AISI 1045钢的加工温度，以证明每个提出模型的预测能力。通过与文献中的记录值进行验证，观察到了密切的一致性。进一步研究了模型输入和计算效率的影响。考虑到易于测量的输入变量，所提出的模型具有高计算效率，能够进行实时预测且实验复杂度低。
