Statistical Analysis of Process Parameters During Micro Milling of Inconel-718 using Cryogenic Fluid as Cutting Coolant.

Abstract

Modern technological devices demand high accuracy miniaturized components. The utilization of such components manufactured by micromachining of super alloys has significantly increased its application in aerospace and automotive industries owing to their exceptional mechanical properties. Such desirable properties make these super alloys extremely challenging to machine and their quality metrics depends upon surface roughness and formation of burr. This research work is related to analyze the impact of several controllable input factors i.e. Feed rate (μm/tooth), Cutting speed (m/min), cutting depth (μm) and tool coating (TIALN, nACo, uncoated) on surface finish and burr width in micro-milling of Nickel based super alloy Inconel-718 using cryogenic fluid as cutting coolant. Scanning electron microscope (SEM) and Stylus profilometer were utilized to investigate machining samples while Anova statistical analysis for the effect and significance of controllable input parameters in order to find the optimum parameters for desired results. An experimental result confirms that cryogenic cooling offers a clean and effective route to improve sustainability in contrast to conventional machining procedures. Experimental results show that core factors effecting the burr formation is Depth of cut (DOC) and surface roughness is the cutting velocity. Natures of burr formed during the micro milling of nickel-based alloy Inconel-718 was affected by the depth of cut, chip load and wasn’t affected much by cutting velocity. Among the tool coatings nAco Shows promising results for minimum burr formation and TAILN for reduced surface roughness.