Finite element modeling of the nitinol micro-milling process

Abstract

The demand for miniature precision products is growing rapidly in many industries, which stimulates the need for efficient manufacturing technologies. Micro-milling is the most versatile process for micromachining metals and alloys. Micro-milling is characterized by difficult chip formation conditions and high specific cutting forces. When machining such difficult-to-machine materials as nitinols, these negative effects are significantly amplified due to their special physical and mechanical properties. Therefore, the study of nitinol micro-milling processes to ensure high machining efficiency is a very important issue for the current level of machining technologies. This work is devoted to the development of a finite-element model of machining a groove on the flat surface of a nitinol workpiece (Ni56,5Ti43,5 by weight) with a two-tooth carbide micro-mill in the Deform-3D program. The methodology of model development is described step by step. The features of preparing CAD models of the workpiece and the cutting tool, setting the tool properties, determining the model of the behaviour of the machined material, generating a finite element mesh, and setting the contact conditions are considered. As a result of the finite element modelling of the process of dry micro-milling of nitinol with a 1 mm diameter tool, the cutting forces for the following machining conditions were determined: cutting speed 20 m/min, cutting depth 0.2 mm, feed per tooth 0.003 mm. The adequacy of the developed model was confirmed by comparison with the results of the experimental measurements of cutting forces for the same machining conditions. The developed finite-element model of micro-milling will be used to further optimize the technological parameters of nitinol cutting in order to increase the efficiency of the micromachining process of this material.

Keywords

• niti
• groove
• cutting force
• micro milling cutter
• deform-3d