Surface Roughness Optimization in End Milling of Stainless Steel AISI 304 with Uncoated WC-Co Insert Under Magnetic Field

Abstract

Chatter phenomenon is a major issue as it greatly affects the topography of machined parts. Due to the inconsistent character of chatter, it is extremely difficult to predict resultant surface roughness in a machining process, such as end milling. Also, recent studies have shown that chatter can be suitably damped using magnetic fields. This paper, thus, focuses on a novel approach of minimizing surface roughness in end milling of Mild (Low Carbon) Steel using uncoated WC-Co inserts under magnetic field from permanent magnets. In this experiment, Response Surface Methodology (RSM) approach using DESIGN EXPERT 6.0 (DOE) software was used to design the experiments. The experiments were performed under two different cutting conditions. The first one was cutting under normal conditions, while the other was cutting under the application of magnetic fields from two permanent magnets positioned on opposite sides of the cutter. Surface roughness was measured using Mitutoyo SURFTEST SV-500 profilometer. The subsequent analysis showed that surface roughness was significantly reduced (by as much as 67.21%) when machining was done under the influence of magnetic field. The experimental results were then used to develop a second order empirical mathematical model equation for surface roughness and validated to 95% confidence level by using ANOVA. Finally, desirability function approach was used to optimize the surface roughness within the limiting values attainable in end milling.

Effects of cutting parameters on surface roughness and hardness in milling of AISI 304 steel

“…As for feed rate, it is usually assumed that surface roughness increases with the increase of feed rate, but not in linear proportion [18]. In the present study, a lower value of surface roughness was obtained at a lower feed rate, coinciding with the investigations of Hamdan et al [5], Nurul et al [7], Muñoz-Escalona et al [9].…”

“…Nurul and colleagues [7], revealed that surface roughness was reduced when milling was done under the influence of magnetic field, and feed per tooth had the most significant effect on Ra, followed by cutting speed. Authors recommended a combination of higher cutting speed, lower feed rate, and small depth of cut to produce a good surface roughness in machined stainless steel specimens.…”

“…Based on this review, studies focused on searching for an optimum combination of cutting parameters to obtain a better value of surface roughness such as: high speed machining by Thangarasu et al [6]; articles on medium speed machining by Nurul et al [7], Maurotto et al [8], Muñoz-Escalona et al [9], as well as Kumbhar et al [14]. However, there is not much research on low cutting speed, and the effect of feed rate and cutting speed on workpiece hardness has not been considered; therefore, these are the aims of this work.…”

Optimization of CNC Milling Process by using Different Coatings - A Review

“…A.K.M. Nurul Amin et.al [13] focuses on a novel approach of minimizing surface roughness in end milling of Mild (Low Carbon) Steel using uncoated WC-Co inserts under magnetic field from permanent magnets. The cutting parameters such as cutting speed, feed and depth of cut and response factor was surface roughness were selected.…”