Article

An experimental study of tool wear and cutting force variation in the end milling of Inconel 718 with coated carbide inserts. J Mater Process Tech 180(1-3):296-304

Journal of Materials Processing Technology (Impact Factor: 2.24). 12/2006; 180(1). DOI: 10.1016/j.jmatprotec.2006.07.009
Source: OAI

ABSTRACT

Inconel 718 is a difficult-to-cut nickel-based superalloy commonly used in aerospace industry. This paper presents an experimental study of the tool wear propagation and cutting force variations in the end milling of Inconel 718 with coated carbide inserts. The experimental results showed that significant flank wear was the predominant failure mode affecting the tool life. The tool flank wear propagation in the up milling operations was more rapid than that in the down milling operations. The cutting force variation along with the tool wear propagation was also analysed. While the thermal effects could be a significant cause for the peak force variation within a single cutting pass, the tool wear propagation was believed to be responsible for the gradual increase of the mean peak force in successive cutting passes.

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Available from: Xiaoqi Chen, Apr 16, 2014
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    • "In LAM F a is reduced due to material softening and lower tool wear and F p is altered by (thermal) effects. Down-milling is recommended for machining Inconel 718 because it reduces the effect of work hardening [3] [10] "

    Full-text · Dataset · Oct 2015
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    • "In LAM F a is reduced due to material softening and lower tool wear and F p is altered by (thermal) effects. Down-milling is recommended for machining Inconel 718 because it reduces the effect of work hardening [3] [10] "
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    ABSTRACT: Laser Assisted Milling (LAM) is a hybrid machining technology which combines conventional milling with a localized laser beam. The laser spot heats the uncut workpiece material in front of the cutting edge. The aim of this technology is to improve the machinability of difficult to cut alloys, like Inconel 718. Hence, the material strength is reduced by high temperatures in the hot cutting process. Indeed, Inconel 718 is widely used in aerospace industry due to its excellent mechanical strength and corrosion resistance at high temperatures. These properties result in poor machinability and high tool wear. In this paper experiments of LAM and conventional milling of Inconel 718 were performed by using ceramic inserts. Methods from the Design of Experiment (DoE) were adopted in order to investigate the influence of laser and milling parameters in the hybrid process. The response variables were measured as tool wear, tool deflection, active machining force Fa and passive force Fp. The results showed that machining forces, tool deflection and also tool wear could be reduced by laser heating, especially using enhanced cutting data.
    Full-text · Article · Jul 2015
    • "Mechanisms of tool wear when machining nickel-base superalloys were reported in various publications [8,22,34,37,41,54–59]. However, most of the work is focused on turning and milling where tool flank wear, edge chipping, plastic deformation [8] [22] [37] [56] [58] and adhesion of work-piece material on the rake face [34] were the dominant failure modes. Attritional wear and thermal cracking at high cutting temperatures were also found to be responsible for tool fractures [57]. "
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    ABSTRACT: The study focuses on the surface integrity and wear mechanisms associated with mechanical micro-drilling of nickel-base superalloy (Inconel 718) under dry and wet cutting conditions. Mechanical and metallurgical characterization was undertaken using scanning electron microscopy (SEM), backscatter electron microscopy (BSE), electron backscatter diffraction microscopy (EBSD), transmission electron microscopy (TEM), focused ion beam (FIB) microscopy, nanoindentation, energy dispersive spectroscopy (EDS) and elemental analysis techniques. The surface integrity results revealed large scale near surface deformations with high dislocation density along with nanocrystalline grain structures both under wet cutting conditions, with evidence of recrystallisation and lower dislocation density for dry cutting. Cutting conditions play a significant role in determining the depth of the affected layer, the frequency of misorientations, the microstructures and the stored energy found there. The cutting temperature and use of coolant play a key role in the formation of the altered surfaces. Abrasion, diffusion and micro-chipping were found to be the main wear mechanisms for wet cutting compared to abrasion, high adhesion, macro-chipping and catastrophic failure for dry cutting. Adhesion of work-piece material to the tool associated with abrasion and diffusion processes is the main contributor to wear phenomena. The results are important in guiding the choice of cutting conditions for acceptable surface integrity.
    No preview · Article · Jan 2014 · International Journal of Machine Tools and Manufacture
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