• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.91-91
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• 2003

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.2
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• pp.17-24
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• 2004

In end milling process, undeformed chip thickness and cutting forces vary periodically with phase change of the tool. Recently, a model has been proposed to simulate the shear and friction characteristics of an up-end milling process in terms of the equivalent oblique cutting to this. In the current study, a down-end milling process has been replaced with the equivalent oblique cutting process. And shear and tool-chip friction characteristics variation of SM45C steel has been studied using the end-mills of different helix angles. The specific shear and friction energy consumed with helix angle of $50^{\circ}$ is somewhat larger than those of$30^{\circ}$ and $40^{\circ}$. The specific shear energy consumed is about 76-77% of the specific cutting energy regardless the helix angles.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.77-82
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• 2003

In end milling process, undeformed chip thickness and cutting force vary periodically with phase change of the tool. Recently, a model has been proposed to simulate the shear and friction characteristics of an up-end milling process in terms of the equivalent oblique cutting to this. In the current study, the varying undeformed chip thickness and the cutting forces in a down-end milling process have been replaced with the equivalent ones of oblique cutting. And, the down-end milling characteristics of SM45C has been compared with that of the up-end milling previously presented with different helix angles.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.302-307
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• 2002

In end milling process, the undeformed chip section area and cutting forces vary periodically with phase change of the tool. However, the real undeformed chip section area deviates from the geometrically ideal one owing to cutter runout and tool shape error. In this study, a method of estimating the real undeformed chip section area which reflects cutter runout and tool shape error was presented during up-end milling of Inconel 718 using measured cutting forces. The specific cutting resistance, K. and $K_t$ are defined as the radial and tangential cutting forces divided by the modified chip section area. Both of $K_r$, and $K_t$ values become smaller as the helix angle increases from $30^\circ$ to $40^\circ$ Whereas they become larder as the helix angle increases from $40^\circ$ to $50^\circ$. On the other hand, the $K_r$, and $K_t$ values show a tendency to decrease with increase of the modified chip section area and this tendency becomes distinct with smaller helix angle.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.308-313
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• 2002

In end milling process, the undeformed chip section area and cutting forces vary periodically with phase change of the tool. However, the real undeformed chip section area deviates from the geometrically ideal one owing to cutter runout and tool shape error. In this study, a method of estimating the real undeformed chip section area which reflects cutter runout and tool shape error was presented during down end-milling of Inconel 715 using measure cutting forces. Contrary to the up-end milling the value of radial specific cutting resistance, $K_r$, becomes larger as the helix angle increases from $30^{\circ}$ to $40^{\circ}$ and it shows almost same value at $50^{\circ}$ The value of tangential specific cutting resistance, $K_t$ becomes larger as the helix angle increases same as in up-end milling, the $KK_r$, and $K_t$ values show a tendency to decrease with increase of the modified chip section area and this tendency is distinct with helix angle $40^{\circ}$.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.8
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• pp.63-70
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• 2002

In end milling process, the undeformed chip section area and cutting forces vary periodically with phase change of the tool. However the real undeformed chip section area deviates from the geometrically ideal one owing to cutter runout and tool shape error. In this study, a method of estimating the real undeformed chip section area which reflects cutter runout and tool shape error was presented in up end milling process using measured cutting forces. The average specific cutting resistance, Ka is defined as the main cutting force component divided by the modified chip section area. Ka value becomes smaller as the helix angle increases from $30^circC \;to\;40\circC$. But it becomes larger as the helix angle increases from $40^\circ$to 50 . On one hand, the Ka value shows a tendency to decrease with increase of the modified chip section area and this tendency becomes distinct with smaller helix angle.