Design and experimental evaluation of an impact damper to be used in a slender end mill tool in the machining of hardened steel

Galarza, Fausto Andrés Maldonado; Albuquerque, Marcos Vieira de; Antonialli, Armando Ítalo Sette; Pederiva, Robson; Diniz, Anselmo Eduardo

doi:10.1007/s00170-019-04786-9

“…4 and Fig. 5a), since the tests carried out by Kull Neto et al [24] and Galarza et al [22] showed that, during copy milling, this strategy generates a better surface finish. All the measurements were performed considering a lead angle of 5° for region 1, 45° for region 2 and 85° for region 3, as illustrated by the blue areas highlighted in Fig.…”

Section: Fig 1 Workpiece and Dynamometer Fixationmentioning

confidence: 93%

An Experimental Evaluation of Particle Impact Dampers Applied on the Tool for Milling of Hardened Steel Complex Surface

Saciotto

¹

,

Diniz

²

2021

Preprint

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In the manufacturing of dies and molds, vibrations may represent serious problems, since the finishing tool used is usually slender (high Length / Diameter ratio) in order to machine deep cavities with complex geometry, typical of these products. Vibration is an undesirable phenomenon in any machining operation as it can lead to poor surface finish, lower material removal rate and increased tool wear. The use of impact dampers in the tool has proven to be an effective method for reducing vibration in machining processes. Damping occurs through energy dissipation and linear momentum exchange during intermittent collisions between the main structure (in this case the milling tool) and a free mass (spheres or cylinders placed within a tool cavity). Although efficient, these types of dampers are highly nonlinear. Thus, the aim of this work is to analyze the effect of different materials and geometries (steel spheres, tungsten spheres and steel cylinders) acting as impact dampers inside a ball nose end milling tool. To do so, milling of a convex D6 steel surface was performed, comparing commercial tool holders with dampened ones. The results showed that the tools with impact dampers generated lower values of roughness in the workpiece (around 30% of the value observed in the conventional steel tool holder for the case of steel cylinders and around 40% for both spheres) and presented lower levels of vibration when compared to the same tool without the impact damper, mainly in the machining of workpiece regions where radial and tangential forces are predominant. The tool which used tungsten spheres generated roughness surfaces similar to those obtained with steel spheres, while the tool that used steel cylinders only generated lower roughness in the regions where the axial force component is not predominant, which shows that their performance is highly dependent on the resulting force direction.

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“…4 and Fig. 5a), since the tests carried out by Kull Neto et al [24] and Galarza et al [22] showed that, during copy milling, this strategy generates a better surface finish. All the measurements were performed considering a lead angle of 5° for region 1, 45° for region 2 and 85° for region 3, as illustrated by the blue areas highlighted in Fig.…”

Section: Fig 2 Schematic Drawing Of the Workpiecementioning

confidence: 96%

“…This procedure was repeated until the tool maximum flank wear (VBmax) reached 0.2 mm. This value was used based on the work of [21] and [22], since in finishing operations, flank wear may not reach high values, otherwise it could harm the workpiece surface finish. To obtain the mean roughness (Ra) a portable Mitutoyo Surftest SJ-210 roughness tester was used, with a cut-off (λc) of 0.8 mm [23], connected to a computer containing the SurfTest® SJ210 software.…”

Section: Fig 1 Workpiece and Dynamometer Fixationmentioning

confidence: 99%

“…3). The choice of diameter for spheres and cylinders was based on the Galarza et al [22] work. These authors carried out a study with the same steel tool holder, with steel spheres of different diameters acting as dampers, concluding that the greatest damping was observed for smaller gaps (0.1 mm) between the structure and the spheres, that is, spheres with larger diameters.…”

Section: Fig 2 Schematic Drawing Of the Workpiecementioning

confidence: 99%

“…The increasing in mass and the gap decreasing, which possibly increases the effectivity of collisions, contributed to a greater damping effect. [21] Galarza et al [22] evaluated the impact damper effectiveness during a ball nose end milling of a convex D6 steel surface with 60 HRc hardness. In order to apply the damping system, they drilled a 6 mm diameter and 130 mm length hole in the tool axial direction.…”

Section: Introductionmentioning

confidence: 99%

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An experimental evaluation of particle impact dampers applied on the tool for milling of hardened steel complex surface

Saciotto

¹

,

Diniz

²

2022

Int J Adv Manuf Technol

Self Cite

7

0

View full text Add to dashboard Cite

In the manufacturing of dies and molds, vibrations may represent serious problems, since the finishing tool used is usually slender (high Length / Diameter ratio) in order to machine deep cavities with complex geometry, typical of these products. Vibration is an undesirable phenomenon in any machining operation as it can lead to poor surface finish, lower material removal rate and increased tool wear. The use of impact dampers in the tool has proven to be an effective method for reducing vibration in machining processes. Damping occurs through energy dissipation and linear momentum exchange during intermittent collisions between the main structure (in this case the milling tool) and a free mass (spheres or cylinders placed within a tool cavity). Although efficient, these types of dampers are highly nonlinear. Thus, the aim of this work is to analyze the effect of different materials and geometries (steel spheres, tungsten spheres and steel cylinders) acting as impact dampers inside a ball nose end milling tool. To do so, milling of a convex D6 steel surface was performed, comparing commercial tool holders with dampened ones. The results showed that the tools with impact dampers generated lower values of roughness in the workpiece (around 30% of the value observed in the conventional steel tool holder for the case of steel cylinders and around 40% for both spheres) and presented lower levels of vibration when compared to the same tool without the impact damper, mainly in the machining of workpiece regions where radial and tangential forces are predominant. The tool which used tungsten spheres generated roughness surfaces similar to those obtained with steel spheres, while the tool that used steel cylinders only generated lower roughness in the regions where the axial force component is not predominant, which shows that their performance is highly dependent on the resulting force direction.

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Various beam and shell models for long slender tools in the area of HSC milling

Schmidt,

Ams

2023

Proc Appl Math and Mech

0

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High‐speed‐cutting) milling is an extensively used production process in tool‐making and mold‐making industries. For the purpose of a self‐balancing tool, a hollow shaft is used and filled partially with a fluid. This talk presents different beam and shell models for the investigation of nonlinear vibrations. Therefore, different theories are compared with respect to the influence of geometrical nonlinearities, spin‐softening as well as stress‐stiffening, and also shear deformation. Additionally, a stochastic Wedig–Dimentberg approach is presented for the simulation of a spatial distributed unbalance. Starting with the nonlinear kinematics for the tool‐deformation Hamilton's principle is evaluated for the variational formulation of each model. Regarding to the shear deformation, the theories of Euler‐‐Bernoulli and Ehrenfest–Timoshenko (beam models) as well as Kirchhoff‐‐Love and Mindlin–Reissner (shell models) are used. In the following up, the variational formulation is discretized under usage of a global Ritz approach on the one hand, and on the other hand with a local finite element (FE) discretization. Afterward, the governing system of differential equations is solved and discussed. Different results of rotating and nonrotating tools are presented, which show the available options of each theory and also their limits. In particular, results of the eigenfrequencies including their stochastic distribution, stationary deformation, stability behavior, and various time solutions are shown.

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Design and experimental evaluation of an impact damper to be used in a slender end mill tool in the machining of hardened steel

Cited by 11 publications

References 14 publications

An Experimental Evaluation of Particle Impact Dampers Applied on the Tool for Milling of Hardened Steel Complex Surface

An Experimental Evaluation of Particle Impact Dampers Applied on the Tool for Milling of Hardened Steel Complex Surface

An experimental evaluation of particle impact dampers applied on the tool for milling of hardened steel complex surface

Various beam and shell models for long slender tools in the area of HSC milling

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