Sagapuram, D and Udupa, A and Viswanathan, K and Mann, JB and M'Saoubi, R and Sugihara, T and Chandrasekar, S (2020) On the Cutting of Metals: A Mechanics Viewpoint. In: Journal of Manufacturing Science and Engineering, Transactions of the ASME, 142 (11).
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Abstract
The mechanics of large-strain deformation in cutting of metals is discussed, primarily from viewpoint of recent developments in in situ analysis of plastic flow and microstructure characterization. It is shown that a broad range of deformation parameters can be accessed in chip formation-strains of 1-10, strain rates of 10-105/s, and temperatures up to 0.7Tm-and controlled. This range is far wider than achievable by any other single-stage, severe plastic deformation (SPD) process. The resulting extreme deformation conditions produce a rich variety of microstructures in the chip. Four principal types of chip formation-continuous, shear-localized, segmented, and mushroom-type-as elucidated first by Nakayama (1974, "The Formation of 'Saw-Toothed Chip' in Metal Cutting,"Proceedings of International Conference on Production Engineering, Tokyo, pp. 572-577) are utilized to emphasize the diverse plastic flow phenomena, especially unsteady deformation modes that prevail in cutting. These chip types are intimately connected with the underlying flow, each arising from a distinct mode and triggered by an instability phenomenon. The role of plastic flow instabilities such as shear banding, buckling, and fracture in mediating unsteady flow modes is expounded, along with consequences of the flow modes and chip types for the cutting. Sinuous flow is shown to be the reason why gummy (highly strain-hardening) metals, although relatively soft, are so difficult to cut. Synthesizing the various observations, a hypothesis is put forth that it is the stability of flow modes that determines the mechanics of cutting. This leads to a flow-stability phase diagram that could provide a framework for predicting chip types and process attributes. © 2021 by ASME.
| Item Type: | Journal Article |
|---|---|
| Publication: | Journal of Manufacturing Science and Engineering, Transactions of the ASME |
| Publisher: | American Society of Mechanical Engineers (ASME) |
| Additional Information: | The copyright for this article belongs to The Authors. |
| Keywords: | Industrial wastes; Metals; Microstructure; Plastic flow; Shear flow; Strain hardening; Strain rate, Deformation conditions; Deformation parameter; Flow instabilities; In-situ analysis; Large strain deformation; Microstructure characterization; Severe plastic deformations; Unsteady deformation, Metal cutting |
| Department/Centre: | Division of Mechanical Sciences > Mechanical Engineering |
| Date Deposited: | 10 Jan 2023 11:43 |
| Last Modified: | 10 Jan 2023 11:43 |
| URI: | https://eprints.iisc.ac.in/id/eprint/79021 |
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