Analytical force modelling for micro milling additively fabricated Inconel 625

Abstract

In recent years, miniaturization of components has been concerned with several industrial fields including aerospace, energy, and electronics. This phenomenon resulted in increasing demand of micro-components with complex shape and high strength, often in high-temperature environment. Nickel-based superalloys such as Inconel 625 are a class of material suitable to aforementioned applications and can be successfully processed with Additive Manufacturing (AM). Moreover, micro-milling can be employed to manufacture micro-scale features on the additively fabricated parts or to achieve better surface finishes, as required for high-precision mechanical assemblies. In micro machining, it is possible to notice a lack of scientific study focusses on the material removal behavior of difficulty-to-cut alloys produced via Additive Manufacturing. This paper describes an analytical cutting force model suitable also for AM'd parts which considers the presence of ploughing-and shearing-dominated cutting regimes. A refinement procedure of the cutting force model was defined and applied by performing an experimental work on Inconel 625 samples fabricated by LaserCUSING™. A search algorithm was employed to develop an iterative methodology to determine the unknown cutting force model parameters. The model was successfully utilized to predict how the cutting force is affected as the process parameters change.

Comparison Between Micro Machining of Additively Manufactured and Conventionally Formed Samples of Ti6Al4V Alloy

“…The tool wear was verified with a digital optical microscope and it resulted negligible. The cutting force (Fc) was calculated as a combination of the single components of the cutting load along each direction that have been measured by the force acquisition system [25].…”

Influence of Feed Rate Response (FRR) on Chip Formation in Micro and Macro Machining of Al Alloy

“…Again, with a change of UCT (hc) from below to above the size of CER (r), the formation of discontinuous, transitional and shear localised chips observed for Inconel 718 [39]. Furthermore, the micro milling of additively fabricated material (Inconel 625) renders shearing, transition, and ploughing behavior on a specific cutting force as feed per tooth is reduced [40]. Similar material removal behavior reported for additively manufactured steel , with the transition from shearing to ploughing regime at minimum uncut chip thickness [41].…”

Tool Run-Out in Micro-Milling: Development of an Analytical Model Based on Cutting Force Signal Analysis

“…The implementation of a piezo actuator for compensating tool run-out using workpiece displacement improved the accuracy of the machining operation. As all the experimental procedures required to describe the run-out effect are time-consuming, in [ 24 ] a valid analytical model to estimate cutting forces is presented; it is applied to a wide range of process parameters, specifically for Inconel samples produced from the AM process. A more complex force predictive model is presented in [ 25 ].…”