Browsing by Author "Polvorosa, R."
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Item Effects of high-pressure cooling on the wear patterns on turning inserts used on alloy IN718(2017-04-26) Suárez, A.; López de Lacalle, L. N.; Polvorosa, R.; Veiga, F.; Wretland, A.; FABRIC_INTEL; Tecnalia Research & InnovationSeveral emerging technologies are being explored to increase the efficiency of machining nickel based alloys. These include the so-called assisted machining processes. Within that group, use of high-pressure cooling has been increasing since its introduction in the 1950s by Pigott and Colwell. The present study compares changes in tool wear patterns for high-pressure cooling (HPC) with those for flood cooling during rough face-turning of wrought nickel-based alloy IN 718. The alloy was face-turned with uncoated carbide tools at a contact cutting speed of 30 m/min, using conventional and high-pressure coolants (HPCs) at 8 MPa (80 bar). Tool wear and cutting force components were recorded. HPC reduced flank wear more than 30%, and reduced cutting forces by more than 10%. In contrast, notch wear is higher and becomes predominant in HPC. Temperatures during turning were also measured and compared to the results obtained from finite element modeling to better understand differences in the notch formation tendency for HPCs compared with conventional.Item An investigation of cutting forces and tool wear in turning of Haynes 282(2019-01) Suárez, A.; Veiga, F.; de Lacalle, L. N.López; Polvorosa, R.; Wretland, A.; FABRIC_INTEL; Tecnalia Research & InnovationSuperalloys belong to the group known as difficult to cut materials, and inside this category of material Haynes 282 is considered a novel material with huge applicability subjected to automobile, aerospace and gas turbine industries. The characterization of machining of this new material evidences a lot of importance. Therefore, this paper presents an experimental investigation into the effect of lubricant pressure and material heat treatment on cutting forces, machined surface quality and tool wear evolution on turning of superalloy Haynes 282. Face turning of hollow discs with fixed cutting conditions with cemented carbides tools where carried out to evaluate machinability. The results show that Haynes 282 Alloy in solution annealing Large Grain Solution (LGS) state has better machinability than precipitation hardened Large Grain Aged (LGA) state in terms of force levels and tool wear. In terms of coolant pressure effect, a significant improvement is not observed in the case of High pressure coolant (HiPC).Item Surface integrity and fatigue of non-conventional machined Alloy 718(2019-12) Suárez, A.; Veiga, F.; Polvorosa, R.; Artaza, T.; Holmberg, J.; de Lacalle, L. N.López; Wretland, A.; FABRIC_INTEL; Tecnalia Research & InnovationAlloy 718 is a high-strength, corrosion-resistant nickel chromium-based superalloy frequently used for applications, such as aerospace, marine, nuclear reactor and chemical industries, due to its outstanding inherent properties such as high strength and corrosion resistance at high temperatures together with good creep behaviour. Although, the use of conventional manufacturing processes is prevalent for their use on Alloy 718, alternative manufacturing technologies are gaining importance. This work compares the effects of alternative manufacturing processes, such as Abrasive water jet (AWJ), Wire Electrical Discharge Machining (WEDM) and ultrasound vibration assisted milling (UVAM) with conventional milling during the manufacture of Alloy 718 parts. Surface integrity, hardness, residual stress and fatigue strength obtained from these machining processes have been examined for cutting alloy 718. Results show that both residual stresses and surface roughness are correlated with fatigue strength. UVAM results shown an improvement on the surface integrity of the final workpiece. AWJ and WEDM show poorer results, further work on post-process technologies or process condition selection must be carry out to establish them as an alternative in Alloy 718 cutting operations.Item Tool wear on nickel alloys with different coolant pressures: Comparison of Alloy 718 and Waspaloy(2017-04-01) Polvorosa, R.; Suárez, A.; de Lacalle, L. N.López; Cerrillo, I.; Wretland, A.; Veiga, F.; FABRIC_INTEL; Tecnalia Research & InnovationCurrently, Inconel 718 and Waspalloy are common alloys in the machining of aeroengine components. The former is more known than the latter, so the comparison of tool wear patterns at different coolant pressures can be very significant, and with direct application to real production and research. In both alloys the grain size is key f for the flank and notch wear appearance and successive growth. In the work here presented, results of face-turning testing for both cases are summarized, using cooling at 6 (conventional) and 80 bar. In short, large grain alloy structure leads to higher notch wear, whereas the smaller grain one leads to higher flank wear. However behaviors of both alloys are different in relation to pressure value. Different insert nose wear patterns ere also found, worse in the case of Waspalloy.