The Experts below are selected from a list of 24675 Experts worldwide ranked by ideXlab platform
Jun Zhang - One of the best experts on this subject based on the ideXlab platform.
-
quantitative analysis of Withdrawal Rate on stray grain formation in the platforms of a ni based single crystal dummy blade
Journal of Alloys and Compounds, 2019Co-Authors: Lin Liu, Taiwen Huang, Dejian Sun, Quanzhao Yue, Bin Gan, Jun ZhangAbstract:Abstract Quantitative analysis of Withdrawal Rate on stray grain (SG) formation in the platforms of Ni-base single crystal (SX) dummy blades was carried out through experiments and simulations. The results showed that the tendency of SG formation becomes higher with the increase of Withdrawal Rates from 3 to 12 mm min−1. Considering that SG formation is governed by a competition on the amount of time used for the dendrites branching and the cooling process, the underlying mechanism associated with the influence of Withdrawal Rate on SG formation was then investigated based on the effect of Withdrawal Rate on the thermal profile development and the macrostructural evolutions. Finite element simulation indicated that the thermal profile in the platform is wave-shaped, which results in two kinds of SGs formation; one being isolated in small areas in the platform ends, and the other connecting to a large area across the upper and lower edges of the platform.
-
influence of Withdrawal Rate on the microstructure of ni base single crystal superalloys containing re and ru
Journal of Alloys and Compounds, 2011Co-Authors: Gang Liu, Lin Liu, Jun ZhangAbstract:Abstract The influence of elevated Withdrawal Rate on the microstructure and segregation behavior of Ni-base single-crystal superalloys containing Re and Ru is investigated. The experimental superalloys are processed under a high thermal gradient of approximately 250 K/cm and Withdrawal Rates between 10 and 500 μm/s. With increasing Withdrawal Rate, the dendritic structures and γ′ precipitates in as-cast microstructures are apparently refined. Electron-probe microanalyzer (EPMA) results indicate that the degree of segregation for the constituent elements (e.g. Al, Ta, W, Re etc.) increases initially and then decreases with increasing Withdrawal Rate. In addition, the Re and Ru additions obviously increase the amounts of γ–γ′ eutectic and the tendency of segregation for Al and Ta.
-
influence of directional solidification variables on the microstructure and crystal orientation of am3 under high thermal gradient
Journal of Materials Science, 2010Co-Authors: Xinbao Zhao, Weiguo Zhang, Lin Liu, Jun ZhangAbstract:Solid–liquid interface morphologies of a nickel-base single crystal superalloy AM3 were investigated under high thermal gradient. The critical velocities of planar–cellular and cellular–dendritic transition were greatly increased by high thermal gradients. A high thermal gradient was of great benefit to dendrite refinement. Experimental results showed that the primary and secondary dendrite arm spacings decreased with increasing cooling Rate. As expected, the segregation of elements was suppressed and the size of the gamma prime (γ′) phase decreased significantly with increasing Withdrawal Rates. The shape of γ′ in interdendritic region kept cuboidal at higher Withdrawal Rate. It was found that the Withdrawal Rates had little influence on the crystallographic orientation in high thermal gradient directional solidification.
-
microstructure and stress rupture properties of single crystal superalloy cmsx 2 under high thermal gradient directional solidification
Materials Letters, 2007Co-Authors: Lin Liu, Taiwen Huang, Jun ZhangAbstract:Abstract The interface morphologies of single crystal superalloy CMSX-2 were studied over a range of cooling Rate with large variations in Withdrawal speeds in directional solidification. A superfine cellular structure was obtained under both high thermal gradient up to 1000 K/cm and fast Withdrawal Rate up to 1 mm/s. The high Rate directional solidification results in reduction in primary and secondary dendrite arm spacing, refinement of γ′ phase, reduced microsegregation of alloying elements and smaller size of γ–γ′ eutectics. The rupture life and plasticity of fine structure samples produced in high thermal gradient directional solidification increase significantly than that in conventional directional solidification process at 1323 K.
Lin Liu - One of the best experts on this subject based on the ideXlab platform.
-
Investigation of Microstructure Evolution and Phase Selection of Peritectic Cuce Alloy During High-Temperature Gradient Directional Solidification.
Materials (Basel Switzerland), 2020Co-Authors: Zhaohao Huang, Yongnan Chen, Junxia Xiao, Jianmin Hao, Xianghui Hou, Lin LiuAbstract:In this work, a CuCe alloy was prepared using a directional solidification method at a series of Withdrawal Rates of 100, 25, 10, 8, and 5 μm/s. We found that the primary phase microstructure transforms from cellular crystals to cellular peritectic coupled growth and eventually, changes into dendrites as the Withdrawal Rate increases. The phase constituents in the directionally solidified samples were confirmed to be Cu2Ce, CuCe, and CuCe + Ce eutectics. The primary dendrite spacing was significantly refined with an increasing Withdrawal Rate, resulting in higher compressive strength and strain. Moreover, the cellular peritectic coupled growth at 10 μm/s further strengthened the alloy, with its compressive property reaching the maximum value of 266 MPa. Directional solidification was proven to be an impactful method to enhance the mechanical properties and produce well-aligned in situ composites in peritectic systems.
-
quantitative analysis of Withdrawal Rate on stray grain formation in the platforms of a ni based single crystal dummy blade
Journal of Alloys and Compounds, 2019Co-Authors: Lin Liu, Taiwen Huang, Dejian Sun, Quanzhao Yue, Bin Gan, Jun ZhangAbstract:Abstract Quantitative analysis of Withdrawal Rate on stray grain (SG) formation in the platforms of Ni-base single crystal (SX) dummy blades was carried out through experiments and simulations. The results showed that the tendency of SG formation becomes higher with the increase of Withdrawal Rates from 3 to 12 mm min−1. Considering that SG formation is governed by a competition on the amount of time used for the dendrites branching and the cooling process, the underlying mechanism associated with the influence of Withdrawal Rate on SG formation was then investigated based on the effect of Withdrawal Rate on the thermal profile development and the macrostructural evolutions. Finite element simulation indicated that the thermal profile in the platform is wave-shaped, which results in two kinds of SGs formation; one being isolated in small areas in the platform ends, and the other connecting to a large area across the upper and lower edges of the platform.
-
effect of solidification parameters on the microstructures of superalloy cmsx 6 formed during the downward directional solidification process
Journal of Crystal Growth, 2014Co-Authors: Lin Liu, Jijun Zhang, Fu Wang, Jianping Hong, Samuel Bogner, Andreas BuhrigpolaczekAbstract:Abstract The single crystal Ni-base superalloy CMSX-6 was cast by using the downward directional solidification process (DWDS) using Withdrawal Rates of between 0.0013 and 0.0217 cm/s. The evolutions of as-cast microstructures were characterized as functions of the Withdrawal Rate. The primary and secondary dendrite arm spacings, λ 1 and λ 2 , decreased with increasing Withdrawal Rate, which is similar to the experimental results obtained in the conventional Bridgman process. However, the value of λ 1 and λ 2 measured in the present work is much smaller than that in the Bridgman process. In addition to this, the value of λ 1 cannot be reasonably described by the theoretical models for the primary dendrite arm spacing in which the convection effect was not taken into account. In comparison, the theoretical model of Bouchard and Kirkaldy which considers the convection factor can predict the λ 1 value well in the present work if the dendrite-calibrating factor ( a 1 ) is assumed to be 13.5. The sizes of the γ′ phase in the dendrite and interdendritic regions were also reduced with an increased Withdrawal Rate. The shape of the γ′ phase was cuboidal in the dendritic regions at all experimental Withdrawal Rates. This contrasts with the γ′ phase in the dendrite cores which became more rounded at the highest Withdrawal Rates employed in the present work, due to the low supersaturation and insufficient growth time. With an increased Withdrawal Rate, significant reduction in the size of the γ/γ′ eutectic island was observed in the samples. Meanwhile, the microsegregation of the alloying elements was reduced and the volume fraction of the γ/γ′ eutectic initially decreased and then increased. The difference in the shape of the γ/γ′ eutectic was also found in those samples processed at low Withdrawal Rates as well as at high Withdrawal Rates.
-
influence of Withdrawal Rate on the microstructure of ni base single crystal superalloys containing re and ru
Journal of Alloys and Compounds, 2011Co-Authors: Gang Liu, Lin Liu, Jun ZhangAbstract:Abstract The influence of elevated Withdrawal Rate on the microstructure and segregation behavior of Ni-base single-crystal superalloys containing Re and Ru is investigated. The experimental superalloys are processed under a high thermal gradient of approximately 250 K/cm and Withdrawal Rates between 10 and 500 μm/s. With increasing Withdrawal Rate, the dendritic structures and γ′ precipitates in as-cast microstructures are apparently refined. Electron-probe microanalyzer (EPMA) results indicate that the degree of segregation for the constituent elements (e.g. Al, Ta, W, Re etc.) increases initially and then decreases with increasing Withdrawal Rate. In addition, the Re and Ru additions obviously increase the amounts of γ–γ′ eutectic and the tendency of segregation for Al and Ta.
-
influence of directional solidification variables on the microstructure and crystal orientation of am3 under high thermal gradient
Journal of Materials Science, 2010Co-Authors: Xinbao Zhao, Weiguo Zhang, Lin Liu, Jun ZhangAbstract:Solid–liquid interface morphologies of a nickel-base single crystal superalloy AM3 were investigated under high thermal gradient. The critical velocities of planar–cellular and cellular–dendritic transition were greatly increased by high thermal gradients. A high thermal gradient was of great benefit to dendrite refinement. Experimental results showed that the primary and secondary dendrite arm spacings decreased with increasing cooling Rate. As expected, the segregation of elements was suppressed and the size of the gamma prime (γ′) phase decreased significantly with increasing Withdrawal Rates. The shape of γ′ in interdendritic region kept cuboidal at higher Withdrawal Rate. It was found that the Withdrawal Rates had little influence on the crystallographic orientation in high thermal gradient directional solidification.
Franz H. Messerli - One of the best experts on this subject based on the ideXlab platform.
-
peripheral edema associated with calcium channel blockers incidence and Withdrawal Rate a meta analysis of randomized trials
Journal of Hypertension, 2011Co-Authors: Harikrishna Makani, Sripal Bangalore, Jorge Romero, Nay Htyte, Ronaldo Sevilla Berrios, Hetal Makwana, Franz H. MesserliAbstract:ObjectivePeripheral edema is considered to be a common and annoying adverse effect of calcium channel blockers (CCBs). It has been thought to occur secondary to arteriolar dilatation causing intracapillary hypertension and fluid extravasation. We aimed to evaluate the incidence and Withdrawal Rate o
-
angiotensin converting enzyme inhibitor associated cough deceptive information from the physicians desk reference
The American Journal of Medicine, 2010Co-Authors: Sripal Bangalore, Sunil Kumar, Franz H. MesserliAbstract:Abstract Background Dry cough is a common, annoying adverse effect of all angiotensin-converting enzyme (ACE) inhibitors. The present study was designed to compare the Rate of coughs reported in the literature with reported Rates in the Physicians' Desk Reference (PDR)/ drug label. Methods We searched MEDLINE/EMBASE/CENTRAL for articles published from 1990 to the present about randomized clinical trials (RCTs) of ACE inhibitors with a sample size of at least 100 patients in the ACE inhibitors arm with follow-up for at least 3 months and reporting the incidence or Withdrawal Rates due to cough. Baseline characteristics, cohort enrolled, metrics used to assess cough, incidence, and Withdrawal Rates due to cough were abstracted. Results One hundred twenty-five studies that satisfied our inclusion criteria enrolled 198,130 patients. The pooled weighted incidence of cough for enalapril was 11.48% (95% confidence interval [CI], 9.54% to 13.41%), which was ninefold greater compared to the reported Rate in the PDR/ drug label (1.3%). The pooled weighted Withdrawal Rate due to cough for enalapril was 2.57% (95% CI, 2.40-2.74), which was 31-fold greater compared to the reported Rate in the PDR/ drug label (0.1%). The incidence of cough has increased progressively over the last 2 decades with accumulating data, but it has been reported consistently several-fold less in the PDR compared to the RCTs. The results were similar for most other ACE inhibitors. Conclusion The incidence of ACE inhibitor-associated cough and the Withdrawal Rate (the more objective metric) due to cough is significantly greater in the literature than reported in the PDR /drug label and is likely to be even greater in the real world when compared with the data from RCTs. There exists a gap between the data available from the literature and that which is presented to the consumers (prescribing physicians and patients).
-
angiotensin converting enzyme inhibitor associated cough deceptive information from the physicians desk reference
The American Journal of Medicine, 2010Co-Authors: Sripal Bangalore, Sunil Kumar, Franz H. MesserliAbstract:Abstract Background Dry cough is a common, annoying adverse effect of all angiotensin-converting enzyme (ACE) inhibitors. The present study was designed to compare the Rate of coughs reported in the literature with reported Rates in the Physicians' Desk Reference (PDR)/ drug label. Methods We searched MEDLINE/EMBASE/CENTRAL for articles published from 1990 to the present about randomized clinical trials (RCTs) of ACE inhibitors with a sample size of at least 100 patients in the ACE inhibitors arm with follow-up for at least 3 months and reporting the incidence or Withdrawal Rates due to cough. Baseline characteristics, cohort enrolled, metrics used to assess cough, incidence, and Withdrawal Rates due to cough were abstracted. Results One hundred twenty-five studies that satisfied our inclusion criteria enrolled 198,130 patients. The pooled weighted incidence of cough for enalapril was 11.48% (95% confidence interval [CI], 9.54% to 13.41%), which was ninefold greater compared to the reported Rate in the PDR/ drug label (1.3%). The pooled weighted Withdrawal Rate due to cough for enalapril was 2.57% (95% CI, 2.40-2.74), which was 31-fold greater compared to the reported Rate in the PDR/ drug label (0.1%). The incidence of cough has increased progressively over the last 2 decades with accumulating data, but it has been reported consistently several-fold less in the PDR compared to the RCTs. The results were similar for most other ACE inhibitors. Conclusion The incidence of ACE inhibitor-associated cough and the Withdrawal Rate (the more objective metric) due to cough is significantly greater in the literature than reported in the PDR /drug label and is likely to be even greater in the real world when compared with the data from RCTs. There exists a gap between the data available from the literature and that which is presented to the consumers (prescribing physicians and patients).
Shengkai Gong - One of the best experts on this subject based on the ideXlab platform.
-
effect of Withdrawal Rate on the microsegregation thermophysical properties and spatial orientation of a ni3al based single crystal superalloy
Journal of Alloys and Compounds, 2016Co-Authors: Jian Zhou, Heng Zhang, Yanling Pei, Shengkai GongAbstract:Abstract The effects of Withdrawal Rate (1–300 μm/s) on microsegregation, solidification characteristic temperature, activation energy of melting and spatial orientation of a Re-containing Ni 3 Al based single crystal superalloy were investigated in this study. With increasing Withdrawal Rate, the as-cast microstructure changed from planar to cellular and then to dendritic, and accordingly the microsegregation degree firstly increased and then decreased. Meanwhile, with transforming the microstructure from cellular to dendritic, the activation energy of melting increased while the liquidus and solidus temperatures decreased, and sample with the severest microsegregation degree possessed the lowest liquidus temperature. In addition, the influence of orientation of the seed on the growth of single crystal became more significant with increasing Withdrawal Rate, and the spatial orientation of newly growth dendritic single crystal only strictly inherited that of seed at modeRate Withdrawal Rates.
-
misorientation induced by Withdrawal Rate transition and its effect on intermediate temperature stress rupture properties of a ni3al based single crystal superalloy
Journal of Alloys and Compounds, 2015Co-Authors: Jian Zhou, Heng Zhang, Yanling Pei, Shengkai GongAbstract:Abstract The dendritic Ni 3 Al based single crystal superalloy of [0 0 1] crystal orientation was prepared at constant (50, 100 and 200 μm/s) and changing Withdrawal Rates (from 100 μm/s to 50 μm/s, and from 200 μm/s to 50 μm/s). It was found that the growth history plays significant role in the primary dendrite arm spacing in the ‘as cast’ state, while its influence on the dendrite orientation was little. It is stated that the spatial orientation was the basic factor of intermediate temperature stress rupture properties of complete solution treated alloys, i.e. the samples with orientation close to the [0 0 1]–[0 1 1] boundary exhibit higher stress rupture lives and lower elongations in comparison to the alloys with orientation closer to the [0 0 1]–[1 1 1] boundary. Furthermore, Withdrawal Rate change during solidification resulted in the misorientation, which led to the decrease of intermediate temperature stress rupture lives and elongations.
Sripal Bangalore - One of the best experts on this subject based on the ideXlab platform.
-
peripheral edema associated with calcium channel blockers incidence and Withdrawal Rate a meta analysis of randomized trials
Journal of Hypertension, 2011Co-Authors: Harikrishna Makani, Sripal Bangalore, Jorge Romero, Nay Htyte, Ronaldo Sevilla Berrios, Hetal Makwana, Franz H. MesserliAbstract:ObjectivePeripheral edema is considered to be a common and annoying adverse effect of calcium channel blockers (CCBs). It has been thought to occur secondary to arteriolar dilatation causing intracapillary hypertension and fluid extravasation. We aimed to evaluate the incidence and Withdrawal Rate o
-
angiotensin converting enzyme inhibitor associated cough deceptive information from the physicians desk reference
The American Journal of Medicine, 2010Co-Authors: Sripal Bangalore, Sunil Kumar, Franz H. MesserliAbstract:Abstract Background Dry cough is a common, annoying adverse effect of all angiotensin-converting enzyme (ACE) inhibitors. The present study was designed to compare the Rate of coughs reported in the literature with reported Rates in the Physicians' Desk Reference (PDR)/ drug label. Methods We searched MEDLINE/EMBASE/CENTRAL for articles published from 1990 to the present about randomized clinical trials (RCTs) of ACE inhibitors with a sample size of at least 100 patients in the ACE inhibitors arm with follow-up for at least 3 months and reporting the incidence or Withdrawal Rates due to cough. Baseline characteristics, cohort enrolled, metrics used to assess cough, incidence, and Withdrawal Rates due to cough were abstracted. Results One hundred twenty-five studies that satisfied our inclusion criteria enrolled 198,130 patients. The pooled weighted incidence of cough for enalapril was 11.48% (95% confidence interval [CI], 9.54% to 13.41%), which was ninefold greater compared to the reported Rate in the PDR/ drug label (1.3%). The pooled weighted Withdrawal Rate due to cough for enalapril was 2.57% (95% CI, 2.40-2.74), which was 31-fold greater compared to the reported Rate in the PDR/ drug label (0.1%). The incidence of cough has increased progressively over the last 2 decades with accumulating data, but it has been reported consistently several-fold less in the PDR compared to the RCTs. The results were similar for most other ACE inhibitors. Conclusion The incidence of ACE inhibitor-associated cough and the Withdrawal Rate (the more objective metric) due to cough is significantly greater in the literature than reported in the PDR /drug label and is likely to be even greater in the real world when compared with the data from RCTs. There exists a gap between the data available from the literature and that which is presented to the consumers (prescribing physicians and patients).
-
angiotensin converting enzyme inhibitor associated cough deceptive information from the physicians desk reference
The American Journal of Medicine, 2010Co-Authors: Sripal Bangalore, Sunil Kumar, Franz H. MesserliAbstract:Abstract Background Dry cough is a common, annoying adverse effect of all angiotensin-converting enzyme (ACE) inhibitors. The present study was designed to compare the Rate of coughs reported in the literature with reported Rates in the Physicians' Desk Reference (PDR)/ drug label. Methods We searched MEDLINE/EMBASE/CENTRAL for articles published from 1990 to the present about randomized clinical trials (RCTs) of ACE inhibitors with a sample size of at least 100 patients in the ACE inhibitors arm with follow-up for at least 3 months and reporting the incidence or Withdrawal Rates due to cough. Baseline characteristics, cohort enrolled, metrics used to assess cough, incidence, and Withdrawal Rates due to cough were abstracted. Results One hundred twenty-five studies that satisfied our inclusion criteria enrolled 198,130 patients. The pooled weighted incidence of cough for enalapril was 11.48% (95% confidence interval [CI], 9.54% to 13.41%), which was ninefold greater compared to the reported Rate in the PDR/ drug label (1.3%). The pooled weighted Withdrawal Rate due to cough for enalapril was 2.57% (95% CI, 2.40-2.74), which was 31-fold greater compared to the reported Rate in the PDR/ drug label (0.1%). The incidence of cough has increased progressively over the last 2 decades with accumulating data, but it has been reported consistently several-fold less in the PDR compared to the RCTs. The results were similar for most other ACE inhibitors. Conclusion The incidence of ACE inhibitor-associated cough and the Withdrawal Rate (the more objective metric) due to cough is significantly greater in the literature than reported in the PDR /drug label and is likely to be even greater in the real world when compared with the data from RCTs. There exists a gap between the data available from the literature and that which is presented to the consumers (prescribing physicians and patients).
