Effect of Cr content on microstructures and properties of CoNiCuCrx medium entropy alloys

In this paper, we show a simple method of producing ferromagnetic materials with a Curie temperature above room temperature. The electron paramagnetic resonance (EPR) spectra of Cd1−xCrxTe (0.002 < x < 0.08) were measured with a dependence on temperature (82 K < T < 381 K). Obtained EPR lines were fitted to a Lorentz-shaped curve. The temperature dependencies of the parameters of the EPR lines, such as the peak-to-peak linewidth (Hpp), the intensity (A), as well as the resonance field (Hr), were studied. Ferromagnetism was noticed in samples at high temperatures (near room temperature). For a sample with a nominal concentration of chrome of x = 0.05, a very strong intrinsic magnetic field is observed. The value of the effective gyromagnetic factor for this sample is ge = 30 at T = 240 K. An increase of chrome concentration above x = 0.05 reduces the ferromagnetic properties considerably. Analysis of the temperature dependencies of the integral intensity of EPR spectra was carried out using the Curie–Weiss law and the paramagnetic Curie temperature was obtained.

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Source and Health Risk Assessment of Heavy Metals in Soil–Ginger System in the Jing River Basin of Shandong Province, North China

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18136749 ◽

2021 ◽

Vol 18 (13) ◽

pp. 6749

Author(s):

Songtao Wang ◽

Zongjun Gao ◽

Yuqi Zhang ◽

Hairui Zhang ◽

Zhen Wu ◽

...

Keyword(s):

Heavy Metals ◽

Risk Assessment ◽

River Basin ◽

Soil Profile ◽

Pollution Index ◽

Potential Ecological Risk ◽

Average Concentration ◽

Anthropogenic Factors ◽

Multivariate Statistical ◽

Cr Content

This study investigated the characteristics and sources of heavy metals in a soil–ginger system and assessed their health risks. To this end, 321 topsoil samples and eight soil samples from a soil profile, and 18 ginger samples with root–soil were collected from a ginger-planting area in the Jing River Basin. The average concentration of heavy metals in the topsoil followed the order: Cr > Zn > Pb > Ni > Cu > As > Cd > Hg. In the soil profile, at depths greater than 80 cm, the contents of Cr, Ni, and Zn tended to increase with depth, which may be related to the parent materials, whereas As and Cu contents showed little change. In contrast, Pb content decreased sharply from top to bottom, which may be attributable to external environmental and anthropogenic factors. Multivariate statistical analysis showed that Cr, Ni, Cu, Zn, and Cd contents in soil are affected by natural sources, Pb and As contents are significantly affected by human activities, and Hg content is affected by farmland irrigation. Combined results of the single pollution index (Pi), geo-accumulation index (Igeo), and potential ecological risk assessment (Ei and RI) suggest that soil in the study area is generally not polluted by heavy metals. In ginger, Zn content was the highest (2.36 mg/kg) and Hg content was the lowest (0.0015 mg/kg). Based on the bioconcentration factor, Cd and Zn have high potential for enrichment in ginger. With reference to the limit of heavy metals in tubers, Cr content in ginger exceeds the standard in the study area. Although Cr does not accumulate in ginger, Cr enrichment in soil significantly increases the risk of excessive Cr content in ginger.

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Effect of Cr content on the SHS reaction of Cr–Ti–C system

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2007.10.092 ◽

2008 ◽

Vol 465 (1-2) ◽

pp. 127-131 ◽

Cited By ~ 14

Author(s):

W.N. Zhang ◽

H.Y. Wang ◽

P.J. Wang ◽

J. Zhang ◽

L. He ◽

...

Keyword(s):

Cr Content

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Formation of Cr-rich Nano-clusters and Columns in (Zn,Cr)Te Grown by MBE

MRS Proceedings ◽

10.1557/proc-1183-ff01-11 ◽

2009 ◽

Vol 1183 ◽

Cited By ~ 5

Author(s):

Yôtarõ Nishio ◽

Kôichirô Ishikawa ◽

Shinji Kuroda ◽

Masanori Mitome ◽

Yoshio Bando

Keyword(s):

Magnetic Properties ◽

Substrate Temperature ◽

Crystallographic Orientation ◽

Vertical Direction ◽

Growth Conditions ◽

Chemical Analyses ◽

Mbe Growth ◽

One Dimensional ◽

X Ray ◽

Cr Content

AbstractThe correlation between the Cr aggregation and magnetic properties are investigated for the series of Zn1-xCrxTe films grown by MBE with a systematic variation of growth conditions. Structural and chemical analyses using TEM and energy-dispersive X-ray spectroscopy (EDS) reveal that the crystallinity and the Cr distribution change significantly with the substrate temperature during the MBE growth. For a relatively low average Cr content x ≅ 0.05, it is found that the crystal quality is improved with the increase of the substrate temperature. For a higher average Cr content x ≅ 0.2, the shape of Cr-rich regions is transformed from isolated clusters into one-dimensional nanocolumns with the increase of the substrate temperature. The direction of the nanocolumn formation changes depending on the crystallographic orientation of the grown films. In the magnetization measurements, anisotropic magnetic properties are observed in the films in which Cr-rich nanocolumns are formed in the vertical direction, depending on the relation between the direction of the nanocolumns and the applied magnetic fields.

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Sulfur application alleviates chromium stress in maize and wheat

Open Chemistry ◽

10.1515/chem-2020-0155 ◽

2020 ◽

Vol 18 (1) ◽

pp. 1093-1104

Author(s):

Grzegorz Kulczycki ◽

Elżbieta Sacała

Keyword(s):

Adverse Effects ◽

Mineral Nutrition ◽

Elemental Sulfur ◽

Marked Decrease ◽

Total Yield ◽

Growth Yield ◽

Dry Weight ◽

Total Biomass ◽

Cr Content ◽

Chromium Stress

AbstractThis study aimed to examine the influence of increasing doses of chromium (Cr) (26, 39, and 52 mg kg−1 soil) and elemental sulfur (S) (60 mg kg−1 soil) on growth, yield, and mineral nutrition in wheat and maize. Macro- and micronutrients and Cr concentrations were determined in the aboveground parts of plants. All examined doses of Cr caused a marked decrease in the fresh and dry weight of maize. Wheat was more tolerant than maize, and lower Cr doses caused a small but statistically significant increase in the total yield. Wheat accumulated more than twofold Cr than maize, and the concentrations increased with higher Cr concentrations in the soil. The application of S significantly improved the total biomass production and lowered the Cr content in both plants. Cr changed the mineral nutrition in both cereals, but the pattern of changes observed was not the same. Applying S alleviated some adverse effects caused by the Cr. Hence, it is concluded that the application of elemental S may be an effective strategy to reduce adverse effects in plants grown on soil contaminated by heavy metals, especially Cr.

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Concentration of selected elements in the hair of Madagascar girls in relation to nutritional status and place of residence

British Journal Of Nutrition ◽

10.1017/s0007114521004967 ◽

2021 ◽

pp. 1-32

Author(s):

Magdalena Zielińska-Dawidziak ◽

Magdalena Czlapka-Matyasik ◽

Zofia Wojciechowska ◽

Jędrzej Proch ◽

Przemysław Niedzielski

Keyword(s):

Factor Analysis ◽

Nutritional Status ◽

Inductively Coupled Plasma ◽

Toxic Elements ◽

Scalp Hair ◽

Optical Emission ◽

Place Of Residence ◽

Inductively Coupled ◽

Cr Content ◽

Optical Emission Spectrometer

Abstract Although the children malnutrition in Madagascar and the environmental pollution of this country has been widely discussed, there is no research on the differences in toxic elements accumulation in human body in dependence on nutritional status of Malagasy. Nine elements concentration (Al, As, Cd, Cr, Hg, Ni, Pb, Sn and Sb) was determined in scalp hair of 103 schoolgirls (8–15 years old), living in two areas: urban - close to Antananarivo (UR) and rural Berevo region (RU). Samples were analyzed by an inductively coupled plasma-optical emission spectrometer. The nutritional status was evaluated by Cole’s Index. Underweight was related to higher accumulation of Al, Cd, and Cr in the hair girls, and more common among girls living in RU than UR region (42% vs 28%). Two-factor analysis of variance showed differences in the Al and Cr content in the girls’ hair depending both on their place of residence and nutritional status. This indicates additional consequence of malnutrition to the girls development and health.

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The Relationship Between Magnetism and Microstructure of Ethylene Pyrolysis Furnace Tubes after a Long-term Service

Microscopy and Microanalysis ◽

10.1017/s1431927618015180 ◽

2018 ◽

Vol 24 (5) ◽

pp. 478-487 ◽

Cited By ~ 1

Author(s):

Jingfeng Guo ◽

Tieshan Cao ◽

Congqian Cheng ◽

Xianming Meng ◽

Jie Zhao

Keyword(s):

Saturation Magnetization ◽

Outer Region ◽

Cr Content ◽

Pyrolysis Furnace ◽

The Matrix ◽

Furnace Tube ◽

Primary Carbides ◽

The Relationship ◽

Very High

AbstractThe magnetism and microstructure of Cr25Ni35Nb and Cr35Ni45Nb alloy tubes after 5 years of service were investigated in this paper. The saturation magnetization of the Cr25Ni35Nb alloy tube in the thickness direction is more than 20 emu/g, and the tube becomes ferromagnetic. The inner and outer walls of Cr35Ni45Nb alloy tubes also become ferromagnetic. But the saturation magnetization of the Cr35Ni45Nb alloy tubes approaches to zero in the center zone. The primary carbides M7C3 and NbC are changed into M23C6 and G phase at the outer region of the furnace tube. However, the M23C6-type carbides were replaced by carbon-rich carbides M7C3 at the carburization zone. Cr-depleted zones are formed at the inner and outer walls of the furnace tubes owing to oxidation. Carburization and oxidation reduce the Cr content of the matrix. Accordingly, the saturation magnetization is very high at the carburization zone and Cr-depleted zone. The magnetism of Cr25Ni35Nb and Cr35Ni45Nb alloy tubes has a high correlation with the Cr content of the matrix. Carburization and oxidation are the main reasons that make the paramagnetic ethylene pyrolysis furnace tube change to ferromagnetic.

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Oxidation-Resistance of (Ti,Al,Cr,Y)N Coatings Prepared by Arc Ion Plating

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.177.338 ◽

2010 ◽

Vol 177 ◽

pp. 338-341

Author(s):

Ming Sheng Li ◽

Yong Zhong Fan ◽

Shu Juan Zhang

Keyword(s):

Oxidation Resistance ◽

Crystal Size ◽

Substrate Bias ◽

Compressor Blades ◽

Arc Ion Plating ◽

Ion Plating ◽

Cr Content ◽

Heat Treated ◽

Aero Engine ◽

Engine Compressor

In this study, composite metastable (Ti0.49Al0.49Y0.02)N, (Ti0.44Al0.44Cr0.1Y0.02)N and (Ti0.34Al0.34Cr0.3Y0.02)N coatings were respectively deposited on a wrought martensite steel 1Cr11Ni2W2MoV for aero-engine compressor blades by arc ion plating technique with a pulse substrate bias. All the coatings have B1NaCl phase structure with a (220) preferred orientation and dense structures. The introduction of chromium into the coatings gave rise to a minute shrinkage of crystal lattice and a decrease of crystal size. Annealed at 800°C, Oxidation-resistance of the coatings improved with increased Cr content. But heat-treated at 900°C, the incorporation of Cr gave rise to obvious decrease of oxidation-resistance.

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Characterization of Alloy 214 After Exposure to Superheated Steam at 800 °C

Journal of Nuclear Engineering and Radiation Science ◽

10.1115/1.4037718 ◽

2017 ◽

Vol 4 (1) ◽

Author(s):

Nick Tepylo ◽

Rainier Garcia Sanchez ◽

Xiao Huang

Keyword(s):

Weight Gain ◽

Supercritical Water ◽

Weight Change ◽

Superheated Steam ◽

Substrate Surface ◽

Surface Oxidation ◽

Metal Substrate ◽

Cr Content

In this study, an Al-containing alloy 214 was evaluated in superheated steam at 800 °C for a duration of 600 h. The purpose of using superheated steam was to simulate the supercritical water (SCW) condition at higher temperatures where no commercial SCW rig is currently capable of reaching (800 °C and beyond). After exposure to superheated steam, the weight change and surface oxidation were analyzed. Alloy 214 experienced greater weight gain than IN 625 and Ni20Cr5Al, due to its low Cr content. Formation of both Cr2O3 and Al2O3 was observed on the surface after 300 and 600 h of exposure. However, as exposure progressed, more Ni and Mn-containing spinel started to form, signaling Cr and Al depletion on the metal substrate surface.

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