Next Generation Insert for Forced Coolant Application in Machining of Inconel 718

Abstract

Machining technology has undergone an extensive evolution throughout the last decades in its capability to machine hard-to-cut material. This paper will discuss about the next generation insert with cooling feature coupled with forced coolant in machining Inconel 718. The geometry of the insert was changed in a way which has enlarged the surface area approximately 12% compared to regular insert named as nusselt insert. The idea applied in “nusselt insert” was the relation of increase in surface area to heat dissipation. Forced coolant application has become a way to improve existing metal cutting concepts and improve their current material removal rates without any need for a reengineered machining process.Experiments conducted on the inserts is that the first experiment of its kind in machining technology together with forced coolant and tested in four different inserts. The primary focus of the work was the investigation of the relation between the heat dissipation with an increase in surface area/mass ratio in the cutting interface based on its influence on tool wear. The experimental results showed the nusselt insert have better ability for heat dissipation which has led to significant reduce in tool wear and successfully facing Inconel 718 at vc 105 m/min, f 0.3 mm/rev and ap 1 mm where the regular insert had a catastrophic failure at vc 90 m/min, f 0.1 mm/rev and ap 1 mm. Nusselt insert has shown to increase MRR significantly compared to regular insert.

Influence of Surface Features for Increased Heat Dissipation on Tool Wear

“…530 µm without flank cooling, while the flank wear was reduced to 306 µm with flank cooling [9]. Coolant boiling regions, which left precipitate from coolant below the flank wear seen as dark region from SEM micrograph, Figure 12a,b.…”

“…Results from the flank wear analysis were ambiguous [9,10]. To clarify, the volumetric analysis was performed on the cutting tools seen in Figure 17.…”

“…( a ) Contact area of insert with a p of 1mm and for 6 mm insert radius; ( b ) magnified micrograph shows contact angle 34°; ( c ) conversation of arc length to liner contact length; and ( d ) illustration of maximum flank wear measurement in relation to linear contact length of 3.6 mm and depth of cut line [9,10]. …”

“…During the last years, the investigations have been directed towards using textures in combination with high-pressure coolant to improve the heat transfer rate for improving tool life. Tamil Alagan et al have published works on surface featured inserts with high-pressure coolant for improved heat dissipation from the cutting zone [9,10,11]. Fang and Obikawa [12], investigated on five types of textures on the flank face in combination with high-pressure coolant.…”

Characterization of tool wear when machining alloy 718 with high-pressure cooling using conventional and surface-modified WC–Co tools

“…This was mainly attributed to the fact that the textures act as micro-reservoirs for cutting fluid, and thus increase the cooling and lubricating effect. As shown by N. Tamil Alagan et al [12,13], the combination of tool surface texturing and high pressure cooling is highly promising in achieving an increased heat dissipation from the cutting zone and improved the tool life.…”