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Cutting elastomers is a very common procedure that is used in a wide variety of applications, including rubber product manufacturing, food processing, and surgical process. To conserve energy and improve cutting accuracy, decreasing the cutting force and elastomer deformation is always of interest. Numerous studies have concentrated on methods for reducing cutting force and deformation, but only a few have explained the underlying mechanics of these cutting techniques. Without a deep understanding of elastomer cutting mechanics, it's difficult to improve or develop a new cutting method. To understand the cutting mechanics, the mechanical, tribological, and rheological properties of the elastomer involved in the cutting process will be examined firstly. The properties include the fracture strain under various loading conditions, viscosity, and friction force under various testing conditions. Following that, the cutting mechanics will be investigated in the cutting process based on the strain-based fracture criteria. To have a clear view of the strain distribution of elastomer, an indentation test will be performed rather than a blade cutting test. Additionally, the cutters can minimize the elastomer deformation, and the cutting force will be designed based on the elastomer's properties and cutting mechanics.

Tool conditions are the essential factors in determining the geometric accuracy and the machined surface quality in the milling process. The different mechanisms of tool condition can be classified as tool wear, chipping, and built-up edge. The chipping, which is one of the decisive tool conditions when the brittle milling tools are used in milling, has not been well investigated by previous studies since the chipping is randomly occurs. Therefore, the main objective of this study is to comprehensively investigate the generation and propagation of chipping in the milling process. To realize this objective, the carbide milling tools were used to dry cut 1020 low carbon steel with different combinations of cutting speed and chip load. Under each combination, the cutting tool was evaluated in terms of various tool conditions over a certain cutting distance until the milling tool failed. The result showed that the chipping mainly occurred under the low spindle speed or high chip load per tooth since the cutting force was high. Once the chipping occurred on one flute, other flutes also had the chipping at the same position since the chipping occurred initially increased the chip load per tooth of the next flute. After the chipping was generated, it extended in the following milling process until the width of chipping met the failure criterion. It is found that most of the chipping extended and met the failure criterion in a short cutting distance. However, the chipping which propagated slowly shown three stages with different expansion rates before the end of tool life. Meanwhile, the flank wear was observed on the outline of chipping and was considered as a factor for the chipping propagation since the flank wear increases with the cutting force. The milling test was stopped at the end of tool life, and it was found that the tool life of all the milling tools was shorter than the tool life estimated by using the Taylor equation. However, the Taylor equation only considers the flank wear as a factor for the tool life, whereas, the chipping was dominated in this study.