Characteristics of force generation on C-, R-, A- and M- planes of single-crystal sapphire during ultra-precision machining
Characteristics of force generation on C-, R-, A- and M- planes of single-crystal sapphire during ultra-precision machining
复制标题
单晶蓝宝石超精密加工过程中C、R、A、M平面的力产生特征
DOI：
10.1016/j.mfglet.2022.07.042
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发表时间：
2022
影响因子：
3.9
通讯作者：
Min, Sangkee
中科院分区：
文献类型：
--
作者：
Kwon, Suk Bum;Min, Sangkee
单晶蓝宝石由于其上级材料特性，可应用于工业的各个领域，但由于其硬度高、脆性大，导致加工过程中易产生裂纹，使得高精度、复杂度的蓝宝石零件制造一直具有挑战性。超精密加工（UPM）已被研究作为解决这一问题的解决方案之一，因为它能够以小切削深度的延性模式切割脆性陶瓷。然而，只有少数研究集中在单晶蓝宝石的UPM中的力产生，这对延性模式切割有重大影响。本研究以单晶蓝宝石为研究对象，以材料晶体结构为基础，考虑塑性变形的平均可能性，探讨单晶蓝宝石超微细加工过程中的力响应特性。以5 mm/min的进给速率和1/500斜率，在四个不同的晶面上以各种切割取向实施正交切入切割。在给定的加工条件下，观察了加工过程中的力特性。在韧性区域中，人们发现，力响应的大小显示各向同性的特性，无论切割方向是近似线性成比例的切割深度。然而，力的方向显示出各向异性特征，其高度依赖于滑移/孪生激活的平均可能性。本研究的结果将有助于建立单晶蓝宝石超精密加工过程中的力预测模型。© 2022制造工程师协会（SME）。由爱思唯尔有限公司出版。保留所有权利。
Single-crystal sapphire can be used in various fields in the industry due to its superior material properties, but it has been challenging to fabricate sapphire parts with high accuracy and complexity because of its high hardness and brittleness, which lead to crack generation during the machining process. Ultra-Precision Machining (UPM) has been studied as one of the solutions to overcome this issue as it is able to cut brittle ceramics in ductile mode for small depth of cuts. However, only a few studies have focused on the force generation in UPM of single-crystal sapphire, which has significant impact on ductile mode cutting. This study focused on the characteristics of force response during UPM of single-crystal sapphire considering the average likelihood of plastic deformation based on material crystallographic structure. With a feed rate of 5 mm/min and 1/500 slope, orthogonal plunge cuts were implemented on four different crystal planes in terms of various cutting orientations. The force characteristics during machining were observed in given machining conditions. In the ductile region, it was found that the magnitude of the force response showed isotropic characteristics regardless of cutting orientation by being approximately linearly proportional to the depth of cut. However, the direction of the force showed an anisotropic characteristic that is highly dependent on the average likelihood of slip/twinning activations. The results of this study will contribute to establishing a force prediction model during ultra-precision machining of single-crystal sapphire.© 2022 Society of Manufacturing Engineers (SME). Published by Elsevier Ltd. All rights reserved.