FEM and Analytical Modeling of the Incipient Chip Formation for the Generation of Micro-Features.

Michele Lanzetta,Marco Picchi Scardaoni,Armin Gharibi,Claudia Vivaldi

doi:10.3390/ma14143789

Michele Lanzetta, Marco Picchi Scardaoni + Show 2 more

Open Access

https://doi.org/10.3390/ma14143789

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Journal: Materials	Publication Date: Jul 6, 2021
Citations: 3	License type: CC BY 4.0

Affiliation: Piaggio (Italy), University of Pisa

Abstract

This paper explores the modeling of incipient cutting by Abaqus, LS-Dyna, and Ansys Finite Element Methods (FEMs), by comparing also experimentally the results on different material classes, including common aluminum and steel alloys and an acetal polymer. The target application is the sustainable manufacturing of gecko adhesives by micromachining a durable mold for injection molding. The challenges posed by the mold shape include undercuts and sharp tips, which can be machined by a special diamond blade, which enters the material, forms a chip, and exits. An analytical model to predict the shape of the incipient chip and of the formed grove as a function of the material properties and of the cutting parameters is provided. The main scientific merit of the current work is to approach theoretically, numerically, and experimentally the very early phase of the cutting tool penetration for new sustainable machining and micro-machining processes.

Highlights

The rise of miniaturization and micro-components signals the need for more research to be carried out on micro-machining, whose areas of applications include micro-injection molds, watch components, optical devices, and products for the aerospace, biomedical and electronic industries
A precut was considered as the initial condition, as shown in Figure 9a,b, because cutting cannot be modelled in the classic Ansys workbench vs. the LS Dyna solver available in Ansys
After many decades of the Finite Element Methods (FEMs) simulation of cutting, this preliminary experimental exploration has shown the potential of the FEM by Ansys, LS-Dyna and Abaqus in the early transient phase of micromachining, right after the tool enters the material with a depth of less than 100 μm

Summary

Introduction

The rise of miniaturization and micro-components signals the need for more research to be carried out on micro-machining, whose areas of applications include micro-injection molds, watch components, optical devices, and products for the aerospace, biomedical and electronic industries. This prompts thinking about different machinable materials (metallic alloys, composites, polymers, and ceramics) and their behaviors relative to micromachining [1]. Examples range from highly hydrophobic surfaces that reject liquids and dirt to directional dry adhesive materials that stick only when loaded in a particular direction In many cases, these surfaces are inspired by examples found in nature, such as the lotus leaf, the skin of sharks, or the hierarchical adhesive apparatus found on the feet of geckos and certain arthropods. The fabrication of these surfaces begins with lithographic patterning or direct micromachining of a material such as SU-8 [6], wax [7], or silicon to create a mold, which is used to cast the functional material

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