The Experts below are selected from a list of 138 Experts worldwide ranked by ideXlab platform
A. K. Tieu - One of the best experts on this subject based on the ideXlab platform.
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Investigation on mechanical properties of high speed steel Roll Material by nanoindentation
Materials Research Innovations, 2013Co-Authors: Buyung Kosasih, A. K. TieuAbstract:The hardness and elastic module of carbides and matrix of a high speed steel (HSS) Roll Material have been characterised by nanoindentation in the force range of 5–10 mN. It has been found that a different correlation needs to be applied to convert nanohardness to micro-Vickers hardness for the carbides and matrix. The pile-up phenomenon occurs significantly at the edge of the indent on the HSS matrix after nanoindentation, which resulted in a slight overestimation of the hardness. The nanohardness of the MC carbides, M2C/M7C3 carbides and HSS matrix is ∼20·0, 12·6 and 9·2 GPa, which are in good agreement with the reported values by micro-Vickers test.
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an investigation into the tribological behaviour of a work Roll Material at high temperature
Wear, 2011Co-Authors: A. K. Tieu, Cheng LuAbstract:Abstract The tribological behaviour of work Roll Materials is always a key issue during the hot Rolling of metals where high pressure and high temperature are applied to the strip. In this paper, the oxidation behaviour of a high speed steel Roll Material is investigated by a Gleeble 3500 thermal–mechanical simulator at 700 °C for different oxidation periods in dry air as well as in a moist atmosphere. The surface characteristics after oxidation are characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis. The results indicate that the humid atmosphere has a significant effect on the surface morphology of the oxide scale. A simulation of the hot Rolling process is also conducted on a mini Rolling mill which is incorporated within the Gleeble 3500 simulator. Two types of Roller surfaces are investigated, one is a virgin surface and the other a pre-oxidized surface with 7 μm thick oxide scale. The experimental results show that the two types of Roller surface exhibit quite different tribological behaviour in terms of friction and surface roughness. The Rolling force and friction of pre-oxidized Rolls are higher than that of virgin surface Rolls for different thickness reductions and temperatures.
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in situ investigation of oxidation behaviour in high speed steel Roll Material under dry and humid atmospheres
Corrosion Science, 2010Co-Authors: A. K. Tieu, Mark H Reid, Laichang ZhangAbstract:The oxidation behaviour of a high-speed steel Roll Material has been investigated by a high temperature microscope in the temperatures ranging from 550 to 700 °C in both dry and humid atmospheres. In-situ observations indicate that the oxide scales of the high-speed steel first nucleate at the carbides/matrix interfaces, and then rapidly spread to cover the carbides and followed by continuous growth over the whole surface. Water vapour in oxidizing atmosphere significantly increases the oxidation rates of carbides and the matrix. With the increase in temperature, the roughness of oxidized surface becomes higher for both dry and humid atmospheres.
Cheng Lu - One of the best experts on this subject based on the ideXlab platform.
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an investigation into the tribological behaviour of a work Roll Material at high temperature
Wear, 2011Co-Authors: A. K. Tieu, Cheng LuAbstract:Abstract The tribological behaviour of work Roll Materials is always a key issue during the hot Rolling of metals where high pressure and high temperature are applied to the strip. In this paper, the oxidation behaviour of a high speed steel Roll Material is investigated by a Gleeble 3500 thermal–mechanical simulator at 700 °C for different oxidation periods in dry air as well as in a moist atmosphere. The surface characteristics after oxidation are characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis. The results indicate that the humid atmosphere has a significant effect on the surface morphology of the oxide scale. A simulation of the hot Rolling process is also conducted on a mini Rolling mill which is incorporated within the Gleeble 3500 simulator. Two types of Roller surfaces are investigated, one is a virgin surface and the other a pre-oxidized surface with 7 μm thick oxide scale. The experimental results show that the two types of Roller surface exhibit quite different tribological behaviour in terms of friction and surface roughness. The Rolling force and friction of pre-oxidized Rolls are higher than that of virgin surface Rolls for different thickness reductions and temperatures.
Laichang Zhang - One of the best experts on this subject based on the ideXlab platform.
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in situ investigation of oxidation behaviour in high speed steel Roll Material under dry and humid atmospheres
Corrosion Science, 2010Co-Authors: A. K. Tieu, Mark H Reid, Laichang ZhangAbstract:The oxidation behaviour of a high-speed steel Roll Material has been investigated by a high temperature microscope in the temperatures ranging from 550 to 700 °C in both dry and humid atmospheres. In-situ observations indicate that the oxide scales of the high-speed steel first nucleate at the carbides/matrix interfaces, and then rapidly spread to cover the carbides and followed by continuous growth over the whole surface. Water vapour in oxidizing atmosphere significantly increases the oxidation rates of carbides and the matrix. With the increase in temperature, the roughness of oxidized surface becomes higher for both dry and humid atmospheres.
Hideki Nishida - One of the best experts on this subject based on the ideXlab platform.
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Chemistry of photoresist reclamation
Advances in Resist Technology and Processing XVII, 2000Co-Authors: Hideki Nishida, Akihiko Igawa, Kenji Ohshiro, Itaru ShiibaAbstract:We have studied the chemical changes that result in photoresist used for LCD device manufacturing due to various stresses that the photoresist is subjected to during the recovery and reclamation process. (1) When the Roll coater recovery photoresist is kept open at room temperature for 50 days, needle-shaped crystals formed in the recovery photoresist. Examination by X-ray diffraction revealed that those crystals are ammonium zinc sulfate hexahydrate that was grown owing to the dissolution of the Roll Material of coater. It is possible to avoid this problem by appropriate selection of the Material that comes in contact with photoresist. (2) When new, tightly sealed photoresist was subjected to thermal stress at 40 degrees Celsius for 100 days, a bead-shaped coagulated Material appeared. NMR analysis showed that the coagulated Material was mainly a photosensitive ester tetramer formed by a thermal change. Furthermore, HPLC analysis showed that the tetramer consisted of mainly tetraesters, but contained diesters, triesters, even monoesters. (3) In the case of the spin coating, although there is virtually no damage from physical stress, water content of about 1% is absorbed from the air during the spin-coating process, and the photo-active compound is decomposed by the thermal stress on the photoresist, lowering the photosensitivity. This change in the photosensitivity of the photoresist can be virtually eliminated if the photoresist contains now water so that the photo-active compound chemical change does not occur during the distillation process. (4) In the reclamation of photoresist, (a) the photoresist is coated in a dry nitrogen atmosphere with no water content, and next (b) the photoresist in a coater cup is dissolved by a photoresist solvent and recovered, and then (c) the viscosity of the recovered photoresist is adjusted by distillation, and it is filtered at the end. By adding fresh photoresist, this type of reclamation can be continuously performed.
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Thermal Changes of Photoresist Characteristics
Journal of Photopolymer Science and Technology, 1999Co-Authors: Akio Nomura, Akihiko Igawa, Itaru Shiiba, Hideki NishidaAbstract:We have studied the chemical changes that result in photoresist due to various stresses that the photoresist is subjected to during the recovery and reclamation process.(1) When the Roll coater recovery photoresist is kept open at room temperature for 50 days, needle-shaped crystals formed in recovery photoresist. Examination by X-ray diffraction revealed that those crystals are ammonium zinc sulfate hexahydrate that was dissolved from the Roll Material of coater. It is possible to avoid this problem by appropriate selection of the Material that comes in contact with recovered photoresist.(2) When new, tightly sealed photoresist was subjected to thermal stress at 40°C for 100 days, a bead-shaped coagulated Material appeared. NMR analysis showed that the coagulated Material was mainly a photosensitive ester tetramer formed by a thermal change. In the case of the spin coating, although there is virtually no damage from physical stress, water content of about 1% is absorbed from the air during the spin-coating process, and the photo-active compound is decomposed by the thermal stress on the photoresist, lowering the photosensitivity. This change in the photosensitivity of the photoresist can be virtually eliminated if the photoresist contains no water so that the photo-active compound chemical change does not occur during the distillation process.(3) In the reclamation of photoresist, (a) the photoresist is coated in a dry nitrogen atmosphere with no water content, and next (b) the photoresist in a coater cup is dissolved by a photoresist-solvent and recovered, and then (c) the viscosity of the recovered photoresist is adjusted by distillation is filtered at the end. Fresh photoresist is replenished to it. We offer the resist reprocessor herein.
Rao Jian-hua - One of the best experts on this subject based on the ideXlab platform.
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Present Status and Development of the Roll Material and Its Heat Treatment
West-china Exploration Engineering, 2020Co-Authors: Rao Jian-huaAbstract:With the fast development of Rolling technology of steel, the demand for high performance Roll with long life and high dependability is increasing day by day. For this reason, this paper summaries the study and application of Roll Material and its heat treatment at various stages at home and abroad. It introduces the way to improve the performance of Roll by optimizing chemical composition of steel and improving heat treatment. It also introduces the chemical ingredient and the feature of some new Material in detail. In the end the trend of the Roll Material selection and its heat treatment modes are presented.
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Present status and development trends of Roll Material and its heat treatments
Southern Iron and Steel, 2020Co-Authors: Rao Jian-huaAbstract:With the fast development of Rolling techniques of steel, the demand for high performance Rolls possessing long life and high reliability is increasing day by day. For this reason, this paper summaries the studies and applications of Roll Materials and their heat treatments at home and abroad. It introduces the way to improve the performance of Roll by optimizing chemical composition of the steel and/or improving heat treatments. It also introduces the chemical composition and features of some new Roll Materials in detail. The paper also presents the development trends of the Roll Material and its heat treatment.
