Analysis and Optimization of Machining Hardened Steel AISI 4140 with Self-Propelled Rotary Tools

Abstract

It is necessary to improve the machinability of difficult-to-cut materials such as hardened steel, nickel-based alloys, and titanium alloys as these materials offer superior properties such as chemical stability, corrosion resistance, and high strength to weight ratio, making them indispensable for many applications. Machining with self-propelled rotary tools (SPRT) is considered one of the promising techniques used to provide proper tool life even under dry conditions. In this work, an attempt has been performed to analyze, model, and optimize the machining process of AISI 4140 hardened steel using self-propelled rotary tools. Experimental analysis has been offered to (a) compare the fixed and rotary tools performance and (b) study the effect of the inclination angle on the surface quality and tool wear. Moreover, the current study implemented some artificial intelligence-based approaches (i.e., genetic programming and NSGA-II) to model and optimize the machining process of AISI 4140 hardened steel with self-propelled rotary tools. The feed rate, cutting velocity, and inclination angle were the selected design variables, while the tool wear, surface roughness, and material removal rate (MRR) were the studied outputs. The optimal surface roughness was obtained at a cutting speed of 240 m/min, an inclination angle of 20°, and a feed rate of 0.1 mm/rev. In addition, the minimum flank tool wear was observed at a cutting speed of 70 m/min, an inclination angle of 10°, and a feed rate of 0.15 mm/rev. Moreover, different weights have been assigned for the three studied outputs to offer different optimized solutions based on the designer’s interest (equal-weighted, finishing, and productivity scenarios). It should be stated that the findings of the current work offer valuable recommendations to select the optimized cutting conditions when machining hardened steel AISI 4140 within the selected ranges.

Experimental Study and Verification of New Monolithic Rotary Cutting Tool for an Active Driven Rotation Machining

“…This can influence the resulting machined surface. Compared to self-propelled technology, this monolithic tool reduces the surface roughness of the machined surface Rz by 18 μm [ 25 ] and the value of Ra parameter is stabilised and less than 0.56–1.83 μm, which was achieved in other research [ 14 ]. With ADRT technology and the use of a multi-component tool, the roughness Rz 8 μm [ 7 ] was achieved, which is a higher value compared to the highest value measured after turning with the monolith rotary tool.…”

“…In forced rotation, this angle does not fundamentally affect the rotational speed of the tool, as it is provided by an external drive unit. For a correct setting, it is necessary to investigate λs, since at certain values, there can be a critical increase in cutting force [ 13 , 14 ]. High temperatures are generated at the cutting point when machining materials and overall high cutting forces are generated [ 15 ].…”

Multi-Objective Optimization of the Rotary Turning of Hardened Mold Steel for Energy Saving and Surface Roughness Improvements

“…The machining force components and temperature of the 51200 hardened steel were precisely predicted using a simulation model [12]. Ahmed et al pointed out that the Ra of 0.38 μm and the tool wear of 2.42 μm could be obtained using optimal parameters for rotary turning AISI 4140 steel [13]. Nieslony et al revealed that a higher V in the rotary turning process caused a decreased Ra and stable machining [14].…”

Effects of Process Cutting Parameters on the Ti-6Al-4V Turning with Monolithic Driven Rotary Tool

“…When turning with a conventional tool, a high temperature is generated at the cutting point due to the fact that only one point of the tool is in constant contact, and wear is concentrated at this point as well. Rotary tool machining technology leads to increased material removal, reduced cutting tool wear [ 18 , 19 ], high cooling capacity [ 8 , 20 ], extended tool life [ 21 ], and better integrity of the machined surface. The rotary tool design might be monolithic or consist of a circular cutting insert clamped in a holder that rotates freely around its axis and serves as a continuous cutting edge along its entire circumference [ 22 ].…”