Changes in high-temperature thermal properties of modified YSZ with various rare earth doping elements

Sm2Zr2O7 is one of the promising candidate materials for the next generation thermal barrier coatings because of its excellent thermal properties. But at high temperature the thermal conductivity of rare-earth zirconate increases because of radiation conduction. NiCr2O4, which can absorb the infrared photons intensely, was introduced to reduce the radiation conduction of rare-earth zirconate. NiCr2O4 powder was prepared by coprecipitation. The bulks of Sm2Zr2O7— NiCr2O4 with different content of NiCr2O4 were prepared by using non-pressure sintering. The phase and microstructure of the samples were characterized by XRD and SEM. The optical absorption was also investigated. The absorptivity of the composite, which was generally higher than that of pure Sm2Zr2O7 prepared by coprecipitation and non-pressure sintering, was enhanced with the content of NiCr2O4 increasing. The enhancement of absorptivity will reduce the radiation conduction of rare-earth zirconate potentially.

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Seebeck and Figure of Merit Enhancement by Rare Earth Doping in Yb14-xRExZnSb11 (x = 0.5)

Materials ◽

10.3390/ma12050731 ◽

2019 ◽

Vol 12 (5) ◽

pp. 731 ◽

Cited By ~ 7

Author(s):

Elizabeth Kunz Wille ◽

Navtej Grewal ◽

Sabah Bux ◽

Susan Kauzlarich

Keyword(s):

Solid Solution ◽

Rare Earth ◽

High Temperature ◽

Figure Of Merit ◽

Structure Type ◽

Rare Earth Doping ◽

Metallic Behavior ◽

Metal Compounds ◽

Kondo System ◽

P Type

Yb14ZnSb11 has been of interest for its intermediate valency and possible Kondo designation. It is one of the few transition metal compounds of the Ca14AlSb11 structure type that show metallic behavior. While the solid solution of Yb14Mn1-xZnxSb11 shows an improvement in the high temperature figure of merit of about 10% over Yb14MnSb11, there has been no investigation of optimization of the Zn containing phase. In an effort to expand the possible high temperature p-type thermoelectric materials with this structure type, the rare earth (RE) containing solid solution Yb14-xRExZnSb11 (RE = Y, La) was investigated. The substitution of a small amount of 3+ rare earth (RE) for Yb2+ was employed as a means of optimizing Yb14MnSb11 for use as a thermoelectric material. Yb14ZnSb11 is considered an intermediate valence Kondo system where some percentage of the Yb is formally 3+ and undergoes a reduction to 2+ at ~85 K. The substitution of a 3+ RE element could either replace the Yb3+ or add to the total amount of 3+ RE and provides changes to the electronic states. RE = Y, La were chosen as they represent the two extremes in size as substitutions for Yb: a similar and much larger size RE, respectively, compared with Yb3+. The composition x = 0.5 was chosen as that is the typical amount of RE element that can be substituted into Yb14MnSb11. These two new RE containing compositions show a significant improvement in Seebeck while decreasing thermal conductivity. The addition of RE increases the melting point of Yb14ZnSb11 so that the transport data from 300 K to 1275 K can be collected. The figure of merit is increased five times over that of Yb14ZnSb11 and provides a zT ~0.7 at 1275 K.

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High Temperature Metal−Insulator Transition Induced by Rare-Earth Doping in Perovskite CaMnO3

The Journal of Physical Chemistry C ◽

10.1021/jp809049s ◽

2009 ◽

Vol 113 (28) ◽

pp. 12509-12516 ◽

Cited By ~ 35

Author(s):

Yang Wang ◽

Yu Sui ◽

Jinguang Cheng ◽

Xianjie Wang ◽

Zhe Lu ◽

...

Keyword(s):

Rare Earth ◽

High Temperature ◽

Insulator Transition ◽

Rare Earth Doping ◽

Metal Insulator Transition ◽

Metal Insulator

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The preparation and some high temperature properties of the rare earth trifluorides

10.31274/rtd-180813-2750 ◽

1970 ◽

Author(s):

David Courtland Henderson

Keyword(s):

Rare Earth ◽

High Temperature ◽

High Temperature Properties ◽

Rare Earth Trifluorides ◽

The Rare Earth

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ELEKTRON EQ2

Alloy Digest ◽

10.31399/asm.ad.mg0080 ◽

2015 ◽

Vol 64 (9) ◽

Keyword(s):

Corrosion Resistance ◽

Rare Earth ◽

High Temperature ◽

Magnesium Alloy ◽

North America ◽

Earth Element ◽

High Strength ◽

Heat Treating ◽

Bend Strength ◽

Temperature Performance

Abstract Elektron EQ21 is a casting high strength magnesium alloy developed as a heat treatable alloy with rare earth element additions. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive, shear, and bend strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as casting, forming, heat treating, machining, joining, and surface treatment. Filing Code: Mg-80. Producer or source: Magnesium Elektron Wrought Products, North America.

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ALUCHROM I SE

Alloy Digest ◽

10.31399/asm.ad.ss0823 ◽

2001 ◽

Vol 50 (5) ◽

Keyword(s):

Stainless Steel ◽

Corrosion Resistance ◽

Rare Earth ◽

High Temperature ◽

Rare Earth Elements ◽

Physical Properties ◽

Tensile Properties ◽

Heat Treating ◽

Temperature Performance ◽

Oxidation Resistant

Abstract Aluchrom I SE is an oxidation resistant ferritic stainless steel alloyed with aluminum and rare earth elements. Applications include framework for catalytic automobile muffler systems. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-823. Producer or source: Krupp VDM.

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A NEW WELDING MATERIAL FOR REGENERATION IN THE WELDING TECHNOLOGY BASED ON NICKEL. ANALYSIS OF THE COMPOSITION AND PROPERTIES OF DEFORMABLE HEAT-RESISTANT HIGH-CHROMIUM NICKEL-BASED ALLOYS FOR WELDED PARTS. ANALYSIS OF EXISTING FUELLING STATIONS TYPES AND VEHICLES USING HYDROGEN, HYDROGEN PRODUCTION AND STORING METHODS

10.36381/iamsti.1.2019.43-48 ◽

2019 ◽

pp. 43-48

Author(s):

Ben Nengjun ◽

Zhou Pengfei ◽

Oleksandr Labartkava ◽

Mykhailo Samokhin

Keyword(s):

Rare Earth ◽

High Temperature ◽

Nickel Alloys ◽

Total Content ◽

Operating Conditions ◽

High Temperature Strength ◽

High Chromium ◽

Salt Corrosion ◽

Tcp Phases ◽

The Impact

This work involves an analysis of high-chromium high-temperature deformable wieldable nickel alloys for use in GTE repair assemblies. It is shown that the alloys EP868 (VZh98) and Haynes 230 can be used in welded assemblies with an operating temperature of 800-1100 °C. The alloys Nimonic 81, Nimonic 91, IN 935, IN 939, and Nicrotan 2100 GT also have a high potential for use in welded assemblies. They are characterized by a combination of good weldability, high-temperature strength, and resistance to scaling. There have been conducted studies on high-temperature salt corrosion of model nickel alloys. They allowed establishing the patterns of the impact of base metal alloying with chromium, aluminum, titanium, cobalt, tungsten, molybdenum, niobium, tantalum and rare earth metals on the critical temperature of the start of salt corrosion Tcor and the alloy mass loss. It has been established that alloys with a moderate concentration (13-16%) of chromium can possess satisfactory hightemperature corrosion resistance (HTC resistance) under the operating conditions of ship GTE. The HTC resistance of CrAl-Ti alloys improves upon reaching the ratio Ti/Al ˃ 1. Meanwhile, the ratio Ti/Al ˂ 1 promotes the formation of corrosion products with low protective properties. The positive effect of tantalum on the HTC resistance of alloys is manifested at higher test temperatures than that of titanium, and the total content of molybdenum and tungsten in alloys is limited by the condition 8Mo2 – 2W2 = 89. The presence of refractory elements stabilizes the strengthening phase and prevents formation of the ɳ-phase. However, their excess promotes formation of the embrittling topologically close packed (TCP) phases and boundary carbides of an unfavorable morphology. Based on the studies of the HTC resistance, there has been identified a class of model high-temperature corrosionresistant nickel alloys with a moderate or high chromium content (30%), Ti/Al ˃ 1, and a balanced content of refractory and rare-earth elements.

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Demonstration of Phase Change Thermal Energy Storage in Zinc Oxide Microencapsulated Sodium Nitrate

Applied Sciences ◽

10.3390/app11136234 ◽

2021 ◽

Vol 11 (13) ◽

pp. 6234

Author(s):

Ciprian Neagoe ◽

Ioan Albert Tudor ◽

Cristina Florentina Ciobota ◽

Cristian Bogdanescu ◽

Paul Stanciu ◽

...

Keyword(s):

Zinc Oxide ◽

Thermal Properties ◽

High Temperature ◽

Energy Storage ◽

Phase Change ◽

Thermal Energy ◽

Sodium Nitrate ◽

Thermal Energy Storage ◽

Metal Corrosion ◽

Scanning Calorimetry

Microencapsulation of sodium nitrate (NaNO3) as phase change material for high temperature thermal energy storage aims to reduce costs related to metal corrosion in storage tanks. The goal of this work was to test in a prototype thermal energy storage tank (16.7 L internal volume) the thermal properties of NaNO3 microencapsulated in zinc oxide shells, and estimate the potential of NaNO3–ZnO microcapsules for thermal storage applications. A fast and scalable microencapsulation procedure was developed, a flow calorimetry method was adapted, and a template document created to perform tank thermal transfer simulation by the finite element method (FEM) was set in Microsoft Excel. Differential scanning calorimetry (DSC) and transient plane source (TPS) methods were used to measure, in small samples, the temperature dependency of melting/solidification heat, specific heat, and thermal conductivity of the NaNO3–ZnO microcapsules. Scanning electron microscopy (SEM) and chemical analysis demonstrated the stability of microcapsules over multiple tank charge–discharge cycles. The energy stored as latent heat is available for a temperature interval from 303 to 285 °C, corresponding to onset–offset for NaNO3 solidification. Charge–self-discharge experiments on the pilot tank showed that the amount of thermal energy stored in this interval largely corresponds to the NaNO3 content of the microcapsules; the high temperature energy density of microcapsules is estimated in the range from 145 to 179 MJ/m3. Comparison between real tank experiments and FEM simulations demonstrated that DSC and TPS laboratory measurements on microcapsule thermal properties may reliably be used to design applications for thermal energy storage.

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Multidisciplinary Approaches for Assessing a High Temperature Borehole Thermal Energy Storage Facility at Linköping, Sweden

Energies ◽

10.3390/en14144379 ◽

2021 ◽

Vol 14 (14) ◽

pp. 4379

Author(s):

Max Hesselbrandt ◽

Mikael Erlström ◽

Daniel Sopher ◽

Jose Acuna

Keyword(s):

Thermal Properties ◽

High Temperature ◽

Energy Storage ◽

Thermal Energy ◽

Thermal Energy Storage ◽

Thermal Response ◽

Site Investigation ◽

Thermal Response Test ◽

Response Test ◽

Crystalline Bedrock

Assessing the optimal placement and design of a large-scale high temperature energy storage system in crystalline bedrock is a challenging task. This study applies and evaluates various methods and strategies for pre-site investigation for a potential high temperature borehole thermal energy storage (HT-BTES) system at Linköping in Sweden. The storage is required to shift approximately 70 GWh of excess heat generated from a waste incineration plant during the summer to the winter season. Ideally, the site for the HT-BTES system should be able to accommodate up to 1400 wells to 300 m depth. The presence of major fracture zones, high groundwater flow, anisotropic thermal properties, and thick Quaternary overburden are all factors that play an important role in the performance of an HT-BTES system. Inadequate input data to the modeling and design increases the risk of unsatisfactory performance, unwanted thermal impact on the surroundings, and suboptimal placement of the HT-BTES system, especially in a complex crystalline bedrock setting. Hence, it is crucial that the subsurface geological conditions and associated thermal properties are suitably characterized as part of pre-investigation work. In this study, we utilize a range of methods for pre-site investigation in the greater Distorp area, in the vicinity of Linköping. Ground geophysical methods, including magnetic and Very Low-Frequency (VLF) measurements, are collected across the study area together with outcrop observations and lab analysis on rock samples. Borehole investigations are conducted, including Thermal Response Test (TRT) and Distributed Thermal Response Test (DTRT) measurements, as well as geophysical wireline logging. Drone-based photogrammetry is also applied to characterize the fracture distribution and orientation in outcrops. In the case of the Distorp site, these methods have proven to give useful information to optimize the placement of the HT-BTES system and to inform design and modeling work. Furthermore, many of the methods applied in the study have proven to require only a fraction of the resources required to drill a single well, and hence, can be considered relatively efficient.

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