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This study presents the affects of cryogenic treatment on flank wear (Vb) and surface roughness (Ra) in machining 41Cr4 steel with shallow (SCT (15 h at −80 °C)) and deep (DCT (15 h at −196 °C)) cryogenically treated carbide tools. The study revealed that the cryogenic treatment increases the hardness and wear resistance of coated carbide tools and improves the surface roughness, thanks to the changes in the microstructure. The η-phase is approximately 17.5 and 24.64% higher in the shallow and deep cryogenically treated tool's microstructure than in the untreated tool (U). The best machining performance was founded with the deep cryogenically treated cutting tool. Compared to the untreated tool, shallow and deep cryogenic treatment increased the hardness of the cutting tools by approximately 8.66 and 10.17%. Compared to the untreated cutting tool, the deep cryogenically treated tool was less worn at rates ranging from 13.04 to 18.60% and provided a lower average surface roughness between 2.49 and 20.15%. With increasing feed rate and cutting speed, the amount of cutting tool flank wear also increased. While the surface roughness values decreased slightly with increasing cutting speed, the increasing feed rate caused the surface roughness to increase significantly. The analysis of variance results showed that the most significant parameter on the cutting tool flank wear was heat treatment with a rate of 67.34%, and the most influential parameter on the surface roughness was the feed rate with a rate of 96.33%. [ABSTRACT FROM AUTHOR]

The machining of superalloys being challenging is continuously evolving due to development in cutting tool technology and tool materials. This study comparatively evaluates through mathematical models the machining performance of nanosecond fiber laser-processed micro-dimple and micro-channel textured carbide tools having average diameter/width and depth of 80 and 70 µm, respectively, during dry turning of Inconel 718. This study finds mixed results with both the micro-textured tools. Micro-channel textured tools showed notable improvement in tool life up to 60% over micro-dimple textured tools at lower cutting speeds. However, we found almost the same tool life with both tools at higher cutting speeds. Micro-dimple textured tools produced a better surface finish and lower cutting forces. However, micro-channel textured tools produced a better surface finish at higher cutting speeds. EDS analysis and subsequent elemental mapping affirm a strong adhesion of chip particles and debris on micro-textured tools leading to quick failure of tools. However, this effect was more prominent for micro-dimple textured tools. This study concludes that micro-channel textured tools are the better alternative for dry turning of Inconel 718. However, we find scope for the machinability studies of Inconel 718 with hybrid micro-textured patterns on the rake and flank surfaces. [ABSTRACT FROM AUTHOR]

The high-pressure coolant is considered as a very important point to improve the machining performance. Most of the papers concern the effect of high-pressure coolant on titanium where its efficiency is very important. This paper investigates the application of a high-pressure lubricant during the turning of stainless steel using coated carbide tools to control the chip size through an extensive experimental work. The effects of the cutting conditions, the cutting tool geometries, and the lubricant pressure were studied. A model was developed to clearly understand the mechanical effects of a lubricant on the chip fragmentation. This model is partially based on a Maln experimental analysis in which a high-speed camera was used to define the jet geometry. Finally, the relationship between the cutting conditions and the pressure is meticulously described. [ABSTRACT FROM AUTHOR]

Since the 1960s, the Inconel Alloy 718 has been a standard nickel-based superalloy due to its high strength, balanced mechanical properties, and strong corrosion resistance at relatively low costs and has been widely used in critical aircraft engine components. With the aim of improving productivity and product quality by implementing advanced tools and new process designs, models such as the FE model are utilized to predict the machining performance such as the cutting forces, the tool life, and the surface integrity. In the research area of FEM chip formation simulation, the influence of flank wear on predictions has not been investigated, especially not on the underestimation of the cutting normal force. In this paper, a 2D FEM chip formation model with the coupled Eulerian-Lagrangian (CEL) method has been built to predict cutting forces as well as other material loadings (Brinksmeier et al. Procedia CIRP 13:429–434, 2014; Buchkremer and Klocke Wear 376-377:1156–1163, 2017) in the machining of Direct Aged 718. In order to validate the performance of the FE model, fundamental investigations have been performed in orthogonal cutting with different cutting parameters. Two kinds of cemented carbide cutting tools with different cobalt contents have been applied to achieve different tool wear behaviors. Moreover, the underestimation of the cutting normal force by FEM chip formation simulation has been investigated and solved in consideration of the flank wear. The introduced FE-modeling approach shows precise predictions in terms of the cutting forces and the chip formation. [ABSTRACT FROM AUTHOR]