Process Mechanics – a Guide for Industry 4.0: Modelling Cutting of Nimonic 90 and Ti-6Al-4V

Abstract

The chip formation models developed to date give no exact representation of the physics phenomena occurring during the complex machine cutting process. Despite the large number of investigations and simulations, there is still limited clarity of the real chip formation process. The models try to solve the plastic flow through force or stress simulation, without proper regard to adequate process mechanics. Due to these circumstances, practical evidence is missing. Analyzing this situation very carefully, some scientists founded the Industry 4.0 initiative to create scientific space with new opportunities. Whereas second and third industrial revolutions have been focused on organization and automation — Industry 4.0 is focused on technology, data integration and artificial intelligence (AI). However, before teaching a computer AI, the adequate process mechanics should be systematically developed and understood. This paper presents the complex process mechanics of chip formation with non-linear conditions in the metal microstructure, with two different friction zones, with self-hardening or temperatures effects. These entire phenomena can’t be solved separately because they have an interdependent relationship. The developed mathematical equations for strain and stress lead to square grid deformation in the chip formation zone, and this grid deformation does not disappear after completing the process, so that the theoretical development can be compared with practical results. This will be presented for two different materials Nimonic 90 and Ti-6Al-4V. For Nimonic 90 a built-up-edge (BUE) will be identified, and this is based on the stream-line inflow-angle. Quite contrary is the chip formation process for Ti-6Al-4V. A diffusion process in the interface chip-tool take place resulting in a self-blockade with segmented chip. In addition, the developed temperatures during cutting could be estimated and will be presented for the two different creep-resistant alloys. Finally, a high agreement between the theoretical and experimental results could be documented.