Multi-scale study of initial tool wear on textured alumina coating, and the effect of inclusions in low-alloyed steel

Bejjani, Roland; Collin, M.; Thersleff, Thomas; Odelros, Stina

doi:10.1016/j.triboint.2016.01.021

Cited by 16 publications

(16 citation statements)

References 19 publications

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“…Alumina coatings were found to be very effective in protecting tools against high temperature conditions as in machining. 2–5 The machining performance of alumina coatings has been directly linked to phase and texture of the coating. 3 Different phases of Al 2 O 3 , such as κ and α, have been used; however the as-grown α-Al 2 O 3 was found to be superior.…”

Section: Introduction and Literature Reviewmentioning

confidence: 99%

“…Abrasion wear develops at the flank side of the tools and often results in micro grooves which are parallel to the cutting direction. 2–5,10 Studying the grooves at the microscopic scale can provide additional information about both the workpiece material and the wear type of the cutting tools.…”

Section: Introduction and Literature Reviewmentioning

confidence: 99%

“…Recent work has investigated the flank wear on alumina-coated cutting tools while turning steel. 2,10 This present work includes both flank and rake face wear on the same type of textured alumina-coated tools and how wear progresses with its corresponding wear mechanism when machining four different workpiece materials.…”

Section: Introduction and Literature Reviewmentioning

confidence: 99%

See 2 more Smart Citations

Shift of wear balance acting on CVD textured coatings and relation to workpiece materials

Bejjani

Odelros

Öhman

et al. 2020

Proceedings of the Institution of Mechanical Engineers, Part J:

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Innovative textured alumina coatings have been engineered to boost the performance of cutting tools. Different workpiece materials affect the wear inside the CVD textured alumina coating differently on the crater and flank side of the tools. How the balance in wear changes between the crater and flank side of the tool inside the alumina is not fully understood. Furthermore, any changes in steel elements in the workpiece can affect this balance differently. In this work, the wear of alumina coating has been studied after turning different workpiece materials (low alloy steel with and without Ca, ball bearing steel and stainless steel). The worn surfaces of the inserts were studied and their features related to the different materials. It was found that after machining under similar conditions, each workpiece material leaves a different signature, or worn surface, with unique features in the alumina coating layer. The transition between the sliding to the sticking region was studied in order to help understand the relation to wear when machining different workpiece materials. SEM and topography characteristics were identified on worn surfaces of the coated tools. The resulting worn volume and surface characteristics were related to different wear mechanisms acting on the rake and flank sides of the tool. This work studies the shift in balance between crater and flank wear by identifying different wear mechanisms acting inside the same alumina coating layer when machining different grades of steel. Such work can be a good resource for FEM wear modeling, where good simulation models must take into consideration the physics lying behind the wear types acting on each side of the tool.

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Section: Introduction and Literature Reviewmentioning

confidence: 99%

Section: Introduction and Literature Reviewmentioning

confidence: 99%

Section: Introduction and Literature Reviewmentioning

confidence: 99%

See 1 more Smart Citation

Shift of wear balance acting on CVD textured coatings and relation to workpiece materials

Bejjani

Odelros

Öhman

et al. 2020

Proceedings of the Institution of Mechanical Engineers, Part J:

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“…The maximum temperature is obtained ~ 300 µm onto the rake face, see Figure 1 (b), depending on geometry, workpiece material, cutting data and coating material [11,12]. Most of the heat is generated where the chip starts to form in the primary sheer zone [13] and is then mostly transported away with the chip, hence flowing over the rake face and thus heating that area more than the flank face [11]. The heat load is significantly lower on the flank face than on the rake face due to less plastic deformation in the workpiece material in this contact area with the tool.…”

Section: Metal Cuttingmentioning

confidence: 99%

Physical vapor deposition and thermal stability of hard oxide coatings

Landälv

2019

Linköping Studies in Science and Technology. Dissertations

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Cover images Front side from the left-The magnetron sputtering system used in Paper I to deposit Al-V-O-coatings-Si-rich droplet in as-deposited Al-Cr-Si-O coatings adapted from Figure 4b in Paper II. Sirich marked yellow. STEM micrograph and EDX map merged and rotated 90° CCW from paper II for better fit on the front cover.-Crystalline Cr (red) and Zr (green) segregation observed in a Cr-Zr-O coating after vacuum annealing at 810 °C. Adapted from Figure 10b in paper IV. STEM micrograph (top) and EDX map (bottom). Background image on front and backside Light optical microscope image of Al-V-O-coating after annealing in air at 700 °C, adapted to background image with filter and blue color. V2O5 crystals grown on the γ-Al2O3 coating. Magnification of part of Figure 4 in Paper I (sample with 18 at.% metal fraction V, sample F). Interesting for its beauty rather than industrial application.

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“…The maximum temperature is obtained ~ 300 µm onto the rake face, see Figure 1 (b), depending on geometry, workpiece material, cutting data and coating material [10,11]. Most of the heat is generated where the chip starts to form in the primary sheer zone [12] and is then mostly transported away with the chip, hence flowing over the rake face and thus heating that area more than the flank face [10]. The heat load is significantly lower on the flank face than on the rake face due to less plastic deformation in the workpiece material in this contact area with the tool.…”

Section: Metal Cuttingmentioning

confidence: 99%

Thin Film and Plasma Characterization of PVD Oxides

Landälv¹

2017

Linköping Studies in Science and Technology. Dissertations

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The state-of-the-art tools for machining metals are primarily based on a metal-ceramic composite (WC-Co) coated with different combinations of carbide, nitride and oxide coatings. Combinations of these coating materials are optimized to withstand specific wear conditions. Oxide coatings are especially desired because of their possible high hot hardness, chemical inertness with respect to the workpiece, and their low friction.This thesis deals with process and coating characterization of new oxide coatings deposited by physical vapor deposition (PVD) techniques, focusing on the Cr-Zr-O and Al-Cr-Si-O systems.The thermal stability of α-Cr0.28Zr0.10O0.61 deposited by reactive radio frequency (RF)-magnetron sputtering at 500 °C was investigated after annealing up to 870 °C. The annealed samples showed transformation of α-(Cr,Zr)2O3 and amorphous ZrOx-rich areas into tetragonal ZrO2 and bcc Cr. The instability of the α-(Cr,Zr)2O3 is surprising and possibly related to the annealing being done under vacuum, facilitating the loss of oxygen. The stabilization of the room temperature metastable tetragonal ZrO2 phase, due to surface energy effects, may prove to be useful for metal cutting applications. The observed phase segregation of α-(Cr,Zr)2O3 and formation of tetragonal ZrO2 with corresponding increase in hardness for this pseudo-binary oxide system also opens up design routes for pseudo-binary oxides with tunable microstructural and mechanical properties.The inherent difficulties of depositing insulating oxide films with PVD, demanding a closed circuit, makes the investigation of process stability an important part of this research. In this context, we investigated the influence of adding small amount of Si in Al-Cr cathode on plasma characteristics, process parameters, and coating properties. Si was chosen here due to a previous study showing improved erosion behavior of Al-Cr-Si over pure Al-Cr cathode without Si incorporation in the coating.This work shows small improvements in cathode erosion and process stability (lower pressure and cathode voltage) when introducing 5 at % Si in the Al70Cr30-cathode. This also led to fewer droplets at low cathode current and intermediate O2 flow. A larger positive effect on cathode erosion was observed with respect to cleaning the cathode from oxide contamination by increasing cathode current with 50%. However, higher cathode current also resulted in increased amount of droplets in the coating which is undesirable. Through plasma analysis the presence of volatile SiO species could be confirmed but the loss of Si through volatile SiO species was negligible, since the coating composition matched the cathode composition. The positive effect of added Si on the process stability at the cathode surface should be weighed against Si incorporation in the coating. This incorporation may or may not be beneficial for the final application since literature states that Si promotes the metastable γ-phase over the thermodynamically stable α-phase of pure Al2O3, contrary to the effect o...

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Multi-scale study of initial tool wear on textured alumina coating, and the effect of inclusions in low-alloyed steel

Cited by 16 publications

References 19 publications

Shift of wear balance acting on CVD textured coatings and relation to workpiece materials

Shift of wear balance acting on CVD textured coatings and relation to workpiece materials

Physical vapor deposition and thermal stability of hard oxide coatings

Thin Film and Plasma Characterization of PVD Oxides

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