Minimum Quantity Lubricant Flow Analysis in End Milling Processes: A Computational Fluid Dynamics Approach

Abstract

This paper presents a two-dimensional steady-state incompressible analysis for the minimum quantity of lubricant flow in milling operations using a computational fluid dynamics (CFD) approach. The analysis of flow and heat transfer in a four-teeth milling cutter operation was undertaken. The domain of the rotating cutter along with the spray nozzle is defined. Operating cutting and boundary conditions are taken from the literature. A steady-state, pressure-based, planar analysis was performed with a viscous, realizable k-ε model. A mixture of oils and air were sprayed on the tool, which is considered to be rotating and is at a temperature near the melting temperature of the workpiece. Flow fields are obtained from the study. The vector plot of the flow field shows that the flow is not evenly distributed over the cutter surface, as well as the uneven distribution of the lubricant in the direction of the cutter rotation. It can be seen that the cutting fluid has not completely penetrated the tool edges. The turbulence created by the cutter rotation in the proximity of the tool throws oil drops out of the cutting zone. The nozzle position in relation to the feed direction is very important in order to obtain the optimum effect of the MQL flow.

Artificial Neural Network Modeling of Grinding of Ductile Cast Iron using Water Based SiO2 Nanocoolant

“…A cylindrical grinding machine rotates the workpiece as the cutting tool feeds into it. The material removal rate (MRR) depends largely on the machine current and the spark on time in the cutting process (Hussein, Sharma, Bakar, & Kadirgama, 2013;Khan, Rahman, Kadirgama, & Bakar, 2012b;Krajnik et al, 2005;Najiha, Rahman, Kamal, Yusoff, & Kadirgama, 2012). The speed of the material removal rate is specified on the rate of material that is being removed.…”

Electrode Wear Rate of Graphite Electrodes during Electrical Discharge Machining Processes on Titanium Alloy Ti-5Al-2.5Sn

“…To develop the relationship between various EDM process parameters and electrode wear rate, a cylindrical graphite electrode of 20mm diameter and 50mm length was used for machining the work sample. Kerosene was selected as a dielectric because of its high flash point, good dielectric strength, transparent characteristics, low viscosity and specific gravity (Najiha et al, 2012). Each experiment was conducted at a fixed supply voltage, 120V, and at a constant dielectric flushing pressure of 0.15MPa.…”

“…To evaluate electrode wear rate, the electrode was weighed before and after machining using a digital single pan balance (maximum capacity = 210 gm, precision = 0.1 mg), and is reported in units of gm. Electrode wear rate was calculated by measuring the average amount of the electrode eroded and the machining time as follows (Najiha et al, 2012): …”

“…Response surface methodology was employed throughout the experiment to build the connection between the electrode wear rate and process parameters such as peak current, pulse-on time, pulse-off time and servo-voltage. For this reason, the experiment was accomplished according to design of experiment, since design of experiment provides an advantage in saving time and costs by reducing the number of experiments (Najiha et al, 2012). Axial point central composite design (CCD) was adopted as design of experiment.…”

“…Although the above-mentioned tool materials seem to be effective in machining, they cannot be recommended for the machining of titanium and its alloys (Hascalik, Caydas, & Gurun, 2007;Kumar & Singh, 2010;Singh & Singh, 2011). It is recognized that electrical discharge machining can be used effectively in machining hard, high-strength, and temperature-resistant materials (Khan, Rahman, Kadirgama, Maleque, & Ishak, 2011c;Najiha, Rahman, Kamal, Yusoff, & Kadirgama, 2012;Yusoff, Mohamed Suffian, & Taib, 2011). EDM is also a process that demands expertise, and the mechanism of metal erosion during sparking is not fully understood due to the complex thermal conduction behaviors in the machining vicinity (Wang et al, 2012).…”