The Experts below are selected from a list of 3921 Experts worldwide ranked by ideXlab platform
W.p. Tong - One of the best experts on this subject based on the ideXlab platform.
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low temperature Nitriding of 38crmoal steel with a nanostructured surface layer induced by surface mechanical attrition treatment
Surface & Coatings Technology, 2008Co-Authors: Zhengsheng Han, W.p. Tong, L. M. Wang, Jian Lu, K LuAbstract:A nanocrystalline surface layer was fabricated on a 38CrMoAl steel plate by means of a surface mechanical attrition treatment (SMAT). The average grain size in the top surface layer (10 pm thick) is about 10 nm, and the grain size stability can be maintained up to 450 degrees C. The effect of the surface nanocrystalline layer on the gas Nitriding Process at a lower temperature was investigated by using structural analysis and wear property measurements. The surface nanocrystallization evidently enhances nitricling kinetics and promotes the formation of an ultrafine polycrystalline compound layer. The results of the investigation showed that this new gas Nitriding technique can effectively increase the hardness and wear resistance of the resulting surface layer in comparison with conventional Nitriding, demonstrating a significant advancement for materials Processing. (c) 2008 Elsevier B.V. All rights reserved.
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low temperature Nitriding of 38crmoal steel with a nanostructured surface layer induced by surface mechanical attrition treatment
Surface & Coatings Technology, 2008Co-Authors: Zhengsheng Han, W.p. Tong, L. M. Wang, Jian Lu, K LuAbstract:A nanocrystalline surface layer was fabricated on a 38CrMoAl steel plate by means of a surface mechanical attrition treatment (SMAT). The average grain size in the top surface layer (10 pm thick) is about 10 nm, and the grain size stability can be maintained up to 450 degrees C. The effect of the surface nanocrystalline layer on the gas Nitriding Process at a lower temperature was investigated by using structural analysis and wear property measurements. The surface nanocrystallization evidently enhances nitricling kinetics and promotes the formation of an ultrafine polycrystalline compound layer. The results of the investigation showed that this new gas Nitriding technique can effectively increase the hardness and wear resistance of the resulting surface layer in comparison with conventional Nitriding, demonstrating a significant advancement for materials Processing. (c) 2008 Elsevier B.V. All rights reserved.
K Lu - One of the best experts on this subject based on the ideXlab platform.
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low temperature Nitriding of 38crmoal steel with a nanostructured surface layer induced by surface mechanical attrition treatment
Surface & Coatings Technology, 2008Co-Authors: Zhengsheng Han, W.p. Tong, L. M. Wang, Jian Lu, K LuAbstract:A nanocrystalline surface layer was fabricated on a 38CrMoAl steel plate by means of a surface mechanical attrition treatment (SMAT). The average grain size in the top surface layer (10 pm thick) is about 10 nm, and the grain size stability can be maintained up to 450 degrees C. The effect of the surface nanocrystalline layer on the gas Nitriding Process at a lower temperature was investigated by using structural analysis and wear property measurements. The surface nanocrystallization evidently enhances nitricling kinetics and promotes the formation of an ultrafine polycrystalline compound layer. The results of the investigation showed that this new gas Nitriding technique can effectively increase the hardness and wear resistance of the resulting surface layer in comparison with conventional Nitriding, demonstrating a significant advancement for materials Processing. (c) 2008 Elsevier B.V. All rights reserved.
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low temperature Nitriding of 38crmoal steel with a nanostructured surface layer induced by surface mechanical attrition treatment
Surface & Coatings Technology, 2008Co-Authors: Zhengsheng Han, W.p. Tong, L. M. Wang, Jian Lu, K LuAbstract:A nanocrystalline surface layer was fabricated on a 38CrMoAl steel plate by means of a surface mechanical attrition treatment (SMAT). The average grain size in the top surface layer (10 pm thick) is about 10 nm, and the grain size stability can be maintained up to 450 degrees C. The effect of the surface nanocrystalline layer on the gas Nitriding Process at a lower temperature was investigated by using structural analysis and wear property measurements. The surface nanocrystallization evidently enhances nitricling kinetics and promotes the formation of an ultrafine polycrystalline compound layer. The results of the investigation showed that this new gas Nitriding technique can effectively increase the hardness and wear resistance of the resulting surface layer in comparison with conventional Nitriding, demonstrating a significant advancement for materials Processing. (c) 2008 Elsevier B.V. All rights reserved.
J A Todd - One of the best experts on this subject based on the ideXlab platform.
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enhancement of cp titanum wear resistance using a two step co2 laser sustained plasma Nitriding Process
Surface & Coatings Technology, 2017Co-Authors: Ama M Kama, Stephe M Copley, A E Segall, J A ToddAbstract:Abstract In this paper, a method of forming hard, wide-area, crack-free, and wear-resistant nitrided cases on commercially-pure titanium using a 3.5 kW CO2 laser-sustained plasma is described. This surface hardening method was comprised of two steps: (1) a laser-sustained nitrogen plasma was first used to nitride the titanium substrate; and (2) a laser-sustained argon plasma was then employed to remelt the nitrided layer deposited in the first step. Previous research using single laser trail experiments had shown that the (second) remelting step can eliminate cracks formed during the (first) Nitriding step and homogenize the nitrided layer. In this work, the two-step Nitriding-remelting Process was extended to wider surface areas by depositing multiple overlapping trails at four different Nitriding speeds and a constant remelting speed. The hardened layer was characterized using x-ray diffraction (XRD), optical metallography, and hardness testing. Reciprocating ball-on-flat wear tests were conducted to assess the wear resistance of the nitrided case, with the wear scar being characterized using scanning electron microscopy (SEM) and optical profilometry. Crack-free, hard cases of depths up to 600 μm and average hardness values up to 641 ± 86 HV0.3 were observed. The LSP Nitriding-remelting treatment was found to improve the wear resistance of the base metal (CP-Ti) by up to 80%.
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a two step laser sustained plasma Nitriding Process for deep case hardening of commercially pure titanium
Surface & Coatings Technology, 2017Co-Authors: Ama M Kama, Stephe M Copley, J A ToddAbstract:Abstract A two-step, laser-sustained plasma (LSP) Process was developed to form deep, hard, nitrided cases on commercially pure titanium. A laser-sustained plasma is plasma generated in a gaseous atmosphere that can be sustained indefinitely by the laser beam away from any potentially interacting surface. The first step utilized a nitrogen LSP associated with a defocused CO 2 laser beam in pure nitrogen gas flow to melt and nitride the titanium surface. The second step used an argon LSP to remelt and refine the nitrided layer. Twenty experimental cases with varying Nitriding and remelting speeds were studied. Optical and scanning electron microscopy, energy dispersive spectroscopy, optical profilometry, and x-ray diffraction were used to characterize the remelted nitrided layer. An analytical moving heat source solution was used to model the heat transfer in the melt pool during the Nitriding and remelting Processes. The mass flux of nitrogen into the melt pool and the efficiency of nitrogen intake were estimated. The remelting treatment was found to eliminate the surface cracks formed during Nitriding, decrease the surface roughness of the nitrided trail, homogenize the hardened surface layer, and refine the microstructure. The microstructures and hardness of the nitrided layers could be tailored by changing the combination of LSP Nitriding and remelting scan speeds. Case depths of up to 0.8 mm and average case hardness values in the range of 475–729 HV 0.3 were achieved in this study.
Zhengxin Lu - One of the best experts on this subject based on the ideXlab platform.
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influence of the surface nanocrystallization on the gas Nitriding of ti 6al 4v alloy
Applied Surface Science, 2013Co-Authors: Liling Ge, Na Tian, Zhengxin LuAbstract:Abstract Supersonic Fine Particle Bombarding (SFPB) was performed on Ti–6Al–4V alloy to form surface nanostructures. The effect of the surface nanostructures on the gas Nitriding was investigated by varying the Nitriding temperature and time. Through SFPB Process, a nanocrystalline surface layer with a mean grain size of 16 nm was obtained, presenting a high hardness of 640 HV. In comparison to the surface without SFPB treatment, the treated surface exhibited a thick nitrogen diffusion layer and high hardness under the same Nitriding Process.
L. M. Wang - One of the best experts on this subject based on the ideXlab platform.
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low temperature Nitriding of 38crmoal steel with a nanostructured surface layer induced by surface mechanical attrition treatment
Surface & Coatings Technology, 2008Co-Authors: Zhengsheng Han, W.p. Tong, L. M. Wang, Jian Lu, K LuAbstract:A nanocrystalline surface layer was fabricated on a 38CrMoAl steel plate by means of a surface mechanical attrition treatment (SMAT). The average grain size in the top surface layer (10 pm thick) is about 10 nm, and the grain size stability can be maintained up to 450 degrees C. The effect of the surface nanocrystalline layer on the gas Nitriding Process at a lower temperature was investigated by using structural analysis and wear property measurements. The surface nanocrystallization evidently enhances nitricling kinetics and promotes the formation of an ultrafine polycrystalline compound layer. The results of the investigation showed that this new gas Nitriding technique can effectively increase the hardness and wear resistance of the resulting surface layer in comparison with conventional Nitriding, demonstrating a significant advancement for materials Processing. (c) 2008 Elsevier B.V. All rights reserved.
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low temperature Nitriding of 38crmoal steel with a nanostructured surface layer induced by surface mechanical attrition treatment
Surface & Coatings Technology, 2008Co-Authors: Zhengsheng Han, W.p. Tong, L. M. Wang, Jian Lu, K LuAbstract:A nanocrystalline surface layer was fabricated on a 38CrMoAl steel plate by means of a surface mechanical attrition treatment (SMAT). The average grain size in the top surface layer (10 pm thick) is about 10 nm, and the grain size stability can be maintained up to 450 degrees C. The effect of the surface nanocrystalline layer on the gas Nitriding Process at a lower temperature was investigated by using structural analysis and wear property measurements. The surface nanocrystallization evidently enhances nitricling kinetics and promotes the formation of an ultrafine polycrystalline compound layer. The results of the investigation showed that this new gas Nitriding technique can effectively increase the hardness and wear resistance of the resulting surface layer in comparison with conventional Nitriding, demonstrating a significant advancement for materials Processing. (c) 2008 Elsevier B.V. All rights reserved.