Prediction of crack initiation in single-crystal sapphire during ultra-precision machining using MD simulation-based slip/fracture activation model
Prediction of crack initiation in single-crystal sapphire during ultra-precision machining using MD simulation-based slip/fracture activation model
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DOI：
10.1016/j.precisioneng.2023.12.007
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发表时间：
2023-12
期刊：
影响因子：
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通讯作者：
S. Kwon;A. Nagaraj;Dae Nyoung Kim;Dalei Xi;Yiyang Du;Woo Kyun Kim;Sangkee Min
中科院分区：
文献类型：
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作者：
S. Kwon;A. Nagaraj;Dae Nyoung Kim;Dalei Xi;Yiyang Du;Woo Kyun Kim;Sangkee Min
在本文中，超精密加工（UPM）的C-，R-和A-平面的蓝宝石的材料变形进行了研究，使用滑移/断裂激活模型，其中的可能性激活的个别塑性变形和断裂系统在不同的晶面计算。从分子动力学（MD）模拟获得的应力数据被利用，和滑动/断裂激活模型，通过将主应力计算塑性变形和断裂解理参数。分析方法被应用于研究材料变形沿着各种切割方向在蓝宝石。采用分子动力学模拟方法计算了蓝宝石C、R和A面超高压加工过程中裂纹萌生的应力场。在考虑系统塑性变形和解理断裂的情况下，建立了裂纹萌生与其触发参数之间的关系方程。该模型可以定性地预测各种切削方向的裂纹萌生。通过超精密正交插削实验沿着相同的切削方向在MD模拟所提出的模型进行了验证。
In this paper, material deformation during ultra-precision machining (UPM) on the C-, R-, and A-planes of sapphire was investigated using the slip/fracture activation model where the likelihood of activation of individual plastic deformation and fracture systems on different crystallographic planes was calculated. The stress data obtained from molecular dynamics (MD) simulations were utilized, and the slip/fracture activation model was developed by incorporating the principal stresses in calculating the plastic deformation and fracture cleavage parameters. The analysis methodology was applied to study material deformation along various cutting orientations in sapphire. The stress field at crack initiation during UPM on C-, R-, and A-planes of sapphire was calculated using molecular dynamics (MD) simulations. An equation describing the relationship between crack initiation and its triggering parameters was formulated considering the systems' plastic deformation and cleavage fractures. The model can qualitatively predict the crack initiations for various cutting orientations. The proposed model was verified through ultra-precision orthogonal plunge cut experiments along the same cutting orientations as in the MD simulations.