The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Kotaro Toyotake - One of the best experts on this subject based on the ideXlab platform.
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Spark anodizing of β-Ti alloy for Wear-Resistant Coating
Surface & Coatings Technology, 2007Co-Authors: Hiroki Habazaki, T. Onodera, Kazuhiro Fushimi, Hidetaka Konno, Kotaro ToyotakeAbstract:Abstract Spark anodizing of a bcc solid solution Ti–15% V–3% Al–3% Cr–3% Sn alloy has been performed in an alkaline electrolyte containing aluminate and phosphate using dc-biased ac anodizing to form a Wear-Resistant Coating on the alloy. The Coating consists mainly of Al 2 TiO 5 , with rutile and γ-Al 2 O 3 being present as minor oxide phases. Depth profiles of the Coating, examined by glow discharge optical emission spectroscopy, have revealed that aluminium species, highly enriched in the Coating, distribute uniformly in the Coating, while phosphorus species, incorporated from the electrolyte, are located mainly in the inner part of the Coating near the Coating/alloy interface. The location of the phosphorus species should be associated with the porous nature of the Coating, allowing access of the electrolyte directly to the inner parts of the Coating. The porosity of the Coating is reduced by anodizing to high voltages. The marked improvement of the wear resistance by the Coating has been demonstrated from a pin-on-disc wear test.
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Spark anodizing of β-Ti alloy for Wear-Resistant Coating
Surface and Coatings Technology, 2007Co-Authors: Hiroki Habazaki, HIDETO KONNO, T. Onodera, Kazuhiro Fushimi, Kotaro ToyotakeAbstract:Spark anodizing of a bcc solid solution Ti-15% V-3% Al-3% Cr-3% Sn alloy has been performed in an alkaline electrolyte containing aluminate and phosphate using dc-biased ac anodizing to form a Wear-Resistant Coating on the alloy. The Coating consists mainly of Al2TiO5, with rutile and γ-Al2O3 being present as minor oxide phases. Depth profiles of the Coating, examined by glow discharge optical emission spectroscopy, have revealed that aluminium species, highly enriched in the Coating, distribute uniformly in the Coating, while phosphorus species, incorporated from the electrolyte, are located mainly in the inner part of the Coating near the Coating/alloy interface. The location of the phosphorus species should be associated with the porous nature of the Coating, allowing access of the electrolyte directly to the inner parts of the Coating. The porosity of the Coating is reduced by anodizing to high voltages. The marked improvement of the wear resistance by the Coating has been demonstrated from a pin-on-disc wear test. © 2006 Elsevier B.V. All rights reserved.
J. Robert Moore - One of the best experts on this subject based on the ideXlab platform.
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Investigation of processing parameters for pulsed closed-field unbalanced magnetron co-sputtered TiC-C thin films
Surface and Coatings Technology, 2006Co-Authors: J. M. Anton, J. Robert Moore, B. Mishra, J.a. Rees, W. D. SproulAbstract:Titanium carbide is a well-established wear resistant Coating due to its excellent tribological properties including high hardness and elastic modulus, good wear resistance, low coefficient of friction against steel, and high temperature stability. Recent advances in sputtering technology have resulted in improvements in the properties and performance of wear resistant Coatings. Closed-field unbalanced magnetron sputtering and pulsed magnetron sputtering have greatly improved the structure and properties of titanium carbide films by increasing ion bombardment at the substrate. The goal of this research was to investigate how processing ties into the structure-property-performance relationship for these types of films. An electrostatic quadrupole plasma analyzer was used to measure the energy of ions at the substrate position. Energy ranges from 0.5 to 280 eV were observed under different pulsing conditions. Excessively high ion energy during deposition was found to erode the tribological performance of films. © 2006 Elsevier B.V. All rights reserved.
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Finite element analysis of a Coating architecture for glass molding dies
Surface and Coatings Technology, 2001Co-Authors: D Zhong, J. Robert Moore, G. G. W. Mustoe, J. DisamAbstract:Finite element analysis (FEA) is being used as an integral part of an overall research program that is being conducted to develop a non-sticking, oxidation- and Wear-Resistant Coating system for glass-molding dies and forming tools. This non-linear thermomechanical FEA consists of two parts: (1) a global analysis using a coupled thermomechanical model of the complete die to predict the locations where the die experiences extreme stressystrain condition during molding cycles; and (2) a local analysis of the die Coating used to protect the die at those positions where extreme conditions were predicted by the global analysis, to analyze the stresses generated in the Coating system during a simulated glass-molding process. This paper outlines the methodology developed in this work, which can be used to explore the effects of die geometry, die material, and Coating materials on the integrity, reliability and performance of a coated die. This methodology may also be helpful for investigation of the mechanisms relating to the thermal fatigue problem. The preliminary results presented here demonstrate that it is possible to find an optimized Coating architecture with optimal stress transition from the substrate to the outmost working layer by selecting appropriate Coating materials and engineering the compositional gradients of the functionally graded material (FGM) intermediate layer.
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Wettability of NiAl, Ni_Al_N, Ti_B_C, and Ti_B–C_N films by glass at high temperatures
Surface and Coatings Technology, 2000Co-Authors: D Zhong, J. Robert Moore, G. G. W. Mustoe, J. Disam, E. Mateeva, Isaac Dahan, Takahisa Ohno, S. ThielAbstract:The stickingadhesion of glass to glass molding dies and forming tools is a critical problem which limits the quality of glass products and the performance and reliability of molding dies and forming tools. Depositing NiAl, NiAlN, TiBC, and TiBCN Coatings and characterizing their wettability by glass at high temperature are part of an overall program that is being conducted to develop a non-sticking, oxidation resistant, and wear resistant Coating system for glass molding dies and forming tools. The use of contact angle analysis for evaluation of wettability is described in this paper. The contact angles were measured by the sessile drop technique and analyzed by an image analyzer. The film microstructures were studied using cross-sectional TEM technique. Factors affecting the wettability are discussed. NiAl and NiAlN films seemed to offer more potential than TiBC and TiBCN films in terms of non-wettability by glass at high temperatures, they are promising ‘working’ layers for glass molding dies and forming tools.
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Cathodic arc evaporation of functionally graded chromium nitride thin films for wear resistant and forming applications
Materials Science Forum, 1999Co-Authors: A M Peters, J. Robert Moore, I Reimanis, B. Mishra, R. WeissAbstract:In earlier research, chromium nitride thin films were examined for properties of critical load, hardness, residual stress, microstructure, stoichiometry, and wear resistance. It was found that near-stoichiometric Cr-N films exhibited high critical loads, while sub-stoichiometric Cr-N films exhibited high hardness. Based on these findings and the requirements for a well-adhered wear resistant Coating, it was determined that a compositionally graded Coating system could be developed for wear resistant applications. These functionally graded chromium nitride thin films were deposited by cathodic arc evaporation (CAE) onto several substrates including: 52100 tool steel, 304 stainless steel, and M4 tool steel (both hardened and mill-annealed). Cathodic arc evaporation was chosen for its unique advantages over other physical vapor deposition processes. Films were characterized using Knoop indentation and single- and multi-pass scratch testing, to examine hardness, critical load and wear resistance, respectively.
Hiroki Habazaki - One of the best experts on this subject based on the ideXlab platform.
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Spark anodizing of β-Ti alloy for Wear-Resistant Coating
Surface & Coatings Technology, 2007Co-Authors: Hiroki Habazaki, T. Onodera, Kazuhiro Fushimi, Hidetaka Konno, Kotaro ToyotakeAbstract:Abstract Spark anodizing of a bcc solid solution Ti–15% V–3% Al–3% Cr–3% Sn alloy has been performed in an alkaline electrolyte containing aluminate and phosphate using dc-biased ac anodizing to form a Wear-Resistant Coating on the alloy. The Coating consists mainly of Al 2 TiO 5 , with rutile and γ-Al 2 O 3 being present as minor oxide phases. Depth profiles of the Coating, examined by glow discharge optical emission spectroscopy, have revealed that aluminium species, highly enriched in the Coating, distribute uniformly in the Coating, while phosphorus species, incorporated from the electrolyte, are located mainly in the inner part of the Coating near the Coating/alloy interface. The location of the phosphorus species should be associated with the porous nature of the Coating, allowing access of the electrolyte directly to the inner parts of the Coating. The porosity of the Coating is reduced by anodizing to high voltages. The marked improvement of the wear resistance by the Coating has been demonstrated from a pin-on-disc wear test.
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Spark anodizing of β-Ti alloy for Wear-Resistant Coating
Surface and Coatings Technology, 2007Co-Authors: Hiroki Habazaki, HIDETO KONNO, T. Onodera, Kazuhiro Fushimi, Kotaro ToyotakeAbstract:Spark anodizing of a bcc solid solution Ti-15% V-3% Al-3% Cr-3% Sn alloy has been performed in an alkaline electrolyte containing aluminate and phosphate using dc-biased ac anodizing to form a Wear-Resistant Coating on the alloy. The Coating consists mainly of Al2TiO5, with rutile and γ-Al2O3 being present as minor oxide phases. Depth profiles of the Coating, examined by glow discharge optical emission spectroscopy, have revealed that aluminium species, highly enriched in the Coating, distribute uniformly in the Coating, while phosphorus species, incorporated from the electrolyte, are located mainly in the inner part of the Coating near the Coating/alloy interface. The location of the phosphorus species should be associated with the porous nature of the Coating, allowing access of the electrolyte directly to the inner parts of the Coating. The porosity of the Coating is reduced by anodizing to high voltages. The marked improvement of the wear resistance by the Coating has been demonstrated from a pin-on-disc wear test. © 2006 Elsevier B.V. All rights reserved.
W. D. Sproul - One of the best experts on this subject based on the ideXlab platform.
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Investigation of processing parameters for pulsed closed-field unbalanced magnetron co-sputtered TiC-C thin films
Surface and Coatings Technology, 2006Co-Authors: J. M. Anton, J. Robert Moore, B. Mishra, J.a. Rees, W. D. SproulAbstract:Titanium carbide is a well-established wear resistant Coating due to its excellent tribological properties including high hardness and elastic modulus, good wear resistance, low coefficient of friction against steel, and high temperature stability. Recent advances in sputtering technology have resulted in improvements in the properties and performance of wear resistant Coatings. Closed-field unbalanced magnetron sputtering and pulsed magnetron sputtering have greatly improved the structure and properties of titanium carbide films by increasing ion bombardment at the substrate. The goal of this research was to investigate how processing ties into the structure-property-performance relationship for these types of films. An electrostatic quadrupole plasma analyzer was used to measure the energy of ions at the substrate position. Energy ranges from 0.5 to 280 eV were observed under different pulsing conditions. Excessively high ion energy during deposition was found to erode the tribological performance of films. © 2006 Elsevier B.V. All rights reserved.
B.v. Cockeram - One of the best experts on this subject based on the ideXlab platform.
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Wear-Resistant Coatings for cobalt-base alloys
Advanced Materials & Processes, 2000Co-Authors: B.v. CockeramAbstract:High interfacial stresses and Coating failure are expected when a hard Coating protects a more-compliant substrate in applications involving high-stress wear contact. Assuming that small differences in stiffness (or modulus) between the Coating and substrate are required for a Wear-Resistant Coating in such applications, four approaches have been taken to develop such Coatings for cobalt-base alloys. Hardness, scratch adhesion, and nano-indentation testing identified the most promising candidates for cobalt-base alloys: A thin Coating with hard Cr{sub 2}N and less-stiff Cr-N(ss) layers; a thick, four-layered Coating with a 4{mu}m inner layer of Cr-N(ss)/ 1 {mu}m layer of Cr{sub 2}N/4 {micro}m layer of Cr-N(ss)/1 {micro} outer layer of Cr{sub 2}N; a duplex approach of ion nitriding to harden the subsurface,followed by application of a dual-layered Cr{sub 2}N/Cr-N(ss) Coating; and ion nitriding alone. The low scratch adhesion values and high modulus/hardness values indicate that ZrN, TiN, and plasma carburized Coatings represent less beneficial approaches. Two different cobalt-base alloys were studied in this work: Haynes 25 and Stellite 3 (Stoody Deloro Stellite). Based on weight change, profilometry measurements, and metallographic and SEM examinations after four-ball wear testing, the thin Cr{sub 2}N/CrN(ss) coated coupons exhibited a significantly lower wear rate than the uncoated Haynes 25more » coupons. Of greater importance, the thin Cr{sub 2}N/Cr-N(ss) Coatings were adherent on the Stellite 3 intermediate balls and Haynes 25 cups, and prevented the wear of the cobalt-base substrate. based on these results, the thin Cr{sub 2}N/Cr-N(ss) Coating was the best Coating candidate, and this Coating could result in a reduced wear rate and less cobalt wear debris. The ion nitrided coupons exhibited slightly higher wear than the thin Cr{sub 2}N/Cr-N(ss) coated coupons, while the wear of the thin duplex coated coupons was the highest. However, the nitride layer was adherent and protected the Haynes 25 substrate. Therefore, modification of the ion nitriding conditions or surface lapping after nitriding are approaches that may improve the wear resistance of the ion nitriding and duplex Coatings.« less
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Development of Wear-Resistant Coatings for cobalt-base alloys
Surface & Coatings Technology, 1999Co-Authors: B.v. CockeramAbstract:The costs and hazards resulting from nuclear plant radiation exposure with activated cobalt wear debris could potentially be reduced by covering the cobalt-base materials with a wear resistant Coating. However, the hardnesses of many cobalt-base wear alloys are significantly lower than conventional PVD hard Coatings, and mechanical support of the hard Coating is a concern. Four approaches have been taken to minimize the hardness differences between the substrate and PVD hard Coating: (1) use a thin Cr-nitride hard Coating with layers that are graded with respect to hardness, (2) use a thicker, multilayered Coating (Cr-nitride or Zr-nitride) with graded layers, (3) use nitriding to harden the alloy subsurface followed by application of a multilayered Coating of Cr-nitride, and (4) use of nitriding alone. Since little work has been done on application of PVD hard Coatings to cobalt-base alloys, some details on process development and characterization of the Coatings is presented. Scratch testing was used to evaluate the adhesion of the different Coatings. A bench-top rolling contact test was used to evaluate the wear resistance of the Coatings. The test results are discussed, and the more desirable Coating approaches are identified.
