Numerical Analysis of Serrated Chip Formation Mechanism with Johnson-Cook Parameters in Micro-Cutting of Ti6Al4V

Zhongpeng Zheng,Yuchao Bai,Chenbing Ni,Yun Yang,Xin Jin

doi:10.3390/met11010102

Zhongpeng Zheng, Yuchao Bai + Show 3 more

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https://doi.org/10.3390/met11010102

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Abstract

Previous studies have reported significant differences in the Johnson-Cook (J-C) parameters of Ti6Al4V alloy. Thus, various serrated chip morphologies, cutting forces, and cutting temperatures are obtained when different constitutive parameters are used for numerical and simulation analyses, which decreases the reliability of the simulation model. Therefore, it is necessary to investigate and analyze simulation errors due to differences in the J-C parameters. In this study, the mechanism of the serrated chip formation of Ti6Al4V is thoroughly analyzed using the uniformly proportional J-C parameters. The serrated chip sensitivity, shear band spacing, serrated segmentation frequency, chip serration intensity, temperature field, strain energy, and cutting force is obtained. This study aims to improve the accuracy and reliability of the micro-cutting simulation models, as well as a reference for the selection of J-C constitutive parameters of simulation with Ti6Al4V manufactured with different heat treatments and additive manufacturing.

Highlights

The development of technology has led to the demand for micro-products in the automotive, aerospace, electronics, medical implants, biomedicine, and robotics industries, among others
As the formation of serrated chips increases, there is an increase in the frequency and amplitude of the cutting force; the tool is significantly sensitive to distance, wear, and bounces, and the roughness of the machining surface increases
This section focuses on the formation mechanism of the Ti6Al4V serrated chip, the effect of the J-C constitutive parameters on the morphology mechanism of the serrated chip, and the effect of the J-C damage parameters on the formation mechanism of the serrated chip

Summary

Introduction

The development of technology has led to the demand for micro-products in the automotive, aerospace, electronics, medical implants, biomedicine, and robotics industries, among others. Micro-cutting is the key technology to suffice an industry in terms of functionality and size miniaturization [1]. Cheng et al [2] indicated that the cutting depth is generally less than 200 μm, the processing size of micro turning is less than. Given the exceptional material properties of titanium alloys, Ti6Al4V has been analyzed and applied to micro-cutting in several studies [3,4]. Owing to the low thermal conductivity of Ti6Al4V and relatively slow heat dissipation, it is relatively easy to form adiabatic shear bands and serrated chips in traditional micro-cutting machining [5,6]. Fluctuating cutting forces are generated during the formation of serrated chips, which accelerates tool wear and affects the surface quality of machined parts [7,8]. The finite element numerical analysis method constitutes an imperative method to overcome experimental limitations and better explain the experimental mechanism [10,11]

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