Statistical Analysis of Surface Roughness, Burr Formation and Tool Wear in High Speed Micro Milling of Inconel 600 Alloy under Cryogenic, Wet and Dry Conditions

Abstract

Super alloys offer excellent mechanical and chemical properties at elevated temperatures that make them an attractive choice for aerospace, automotive and chemical processing, and marine applications. These alloys are, however, difficult to machine due to their high strength at elevated temperatures, low thermal conductivity and work hardening. In this study, micro milling of Inconel 600 super alloy has been carried out and the effects of the key input parameters (cutting speed, feed rate, depth of cut) on response parameters (burr formation, surface roughness and tool wear), under various cooling conditions (dry, wet and cryogenic), have been analyzed. High speed micro milling (range up to 80,000 RPM) was carried out, while keeping the feed rate values below and above the cutting edge radius. The Taguchi design of experiments was used during this study. The results have been analyzed using SEM and 3D optical microscopy. Analysis of Variance (ANOVA) revealed that the best surface roughness values can be achieved under cryogenic machining condition with an overall contribution ratio of 28.69%. It was also revealed that cryogenic cooling resulted in the highest tool life with the contribution ratio of cooling conditions at 26.52%.

Effect of Cutting Fluid on Machined Surface Integrity and Corrosion Property of Nickel Based Superalloy

“…The three-dimensional roughness, S a, of the machined surfaces is illustrated in Figure 5 . Cutting fluid reduces cutting forces through lubrication and cooling functions, thus reducing surface roughness [ 3 , 34 , 35 ]. It indicates that the machined surface roughness under Blasocut and E709 were almost the same, while that of water was larger (about 10%).…”

“…As a typical difficult-to-cut material, the superalloy used for these key components usually has good comprehensive properties, such as high strength, corrosion resistance, and fatigue resistance. In the machining of such hard-to-cut alloys, high cutting temperature, serious tool wear, poor quality, and other problems are often improved by various auxiliary machining methods, such as nitrogen [ 1 ], CO 2 [ 2 ], and cooling machining, by reducing the cutting temperature to improve the surface quality [ 3 ], while the laser-assisted cutting method reduces cutting force but accelerates tool wear [ 4 ]. MQL lubrication improves surface quality, while reducing tool wear and cutting temperature, due to cooling and local lubrication of the cutting zone [ 5 ].…”

Experimental Evaluation of Surface Roughness, Burr Formation, and Tool Wear during Micro-Milling of Titanium Grade 9 (Ti-3Al-2.5V) Using Statistical Evaluation Methods

“…Therefore, this study adopted feed rates below this radius in contrast to titanium alloy Ti-6Al-4V, for which literature reports cutting speeds ranging from 10,000 rpm to 90,000 rpm [6,17,36,37], no previous investigations have been conducted on cutting speeds specific to titanium grade 9. Consequently, this study selected three cutting speed levels (25,50, and 75 m/min) based on Jaffery et al [16]'s work, where 25 and 50 Vc were chosen. Additionally, the recommended depth of cut guidelines provided by Niagra Tool [38] were considered.…”

“…Researchers conducted another study on micro-milling Inconel 600 super alloy, commonly used in aerospace and high-temperature applications. They found that cryogenic cooling yielded the best surface roughness and extended tool life, making it a valuable cooling method for machining super alloys [25]. Researchers conducted a study on milling Inconel 718 at conventional speeds, comparing uncoated and coated tools.…”

Experimental research on mechanical, material, and metallurgical properties of Inconel 600: Application in elevated temperature environment

“…Inconel 600 is an austenitic and stable solid-solution nickel-chromium based superalloys. It is non-magnetic, has excellent mechanical properties, and provides the desired combination of high strength and good weldability over a wide temperature range [1][2]. Inconel 600 has excellent resistance to oxidation at high temperatures.…”