Characterization of pack cemented Ni2Al3 coating exposed to KCl(s) induced corrosion at 600 °C

Abstract

Oxidation of Ni₂Al₃ produced by pack aluminizing of pure nickel was studied with and without 0.10 mg cm^?2 KCl(s) deposit in an environment containing 5% O₂, 40% H₂O and 55% N₂ at 600 °C for up to 168 h. Oxide microstructure and composition was investigated by SEM/EDX, BIB, TEM and GDOES. Oxidised Ni₂Al₃ shows minimal weight gain, while adding KCl results in a small weight loss consistent with evaporation of KCl. On the surface of samples exposed to the gas environment only, a 30 nm oxide of Al oxide was present, but where KCl was present as deposit, 50–250 nm thick nodules form that are enriched in K, O and Al.     

Effect of microstructure on KCl corrosion attack of modified AISI 310 steel

Abstract

The effect of microstructure on KCl corrosion attack was studied using a specifically chosen modified AISI 310 austenitic steel in a 15% (v/v) H₂O (g) + 5%(v/v) O₂ (g) + N₂ (g) (balance) atmosphere at 600°C for 168 h. The material was a targeted choice as it allows investigation of different microstructures i.e. as-received (without sigma phase) and heat-treated (29% σ-phase per area) microstructures. The corrosion attack was studied with light optical, scanning electron and transmission electron microscopy as well as X-ray diffraction. The heat-treated sample showed a corrosion attack that was 5 times higher than the as-received sample. In the heat-treated sample, the σ-phase was selectively attacked. At the corrosion front, chlorine (but not potassium) was detected in the selectively attacked σ- phase but not in the unattacked adjacent matrix. Therefore, the corrosion attack was propagated by preferential σ-phase attack by chlorine species.     

STUDY ON THE MICROSTRUCTURE OF Fe-KCl GRAPHITE INTERCALATION COMPOUND

The intercalatants presence of Fe-KCl graphite intercalation compound(Fe-KCl GIC) is in the form of independent crystalline phase. In this paper, its distribution in the carbon interlayer, crystalline status and powder sizes have been studied by X-ray diffraction (XRD), small angle X-ray scattering(SAXS) and transmission electron microscope (TEM). And the partial crystal structure of the GIC has been researched too.     

KCl:Li FA(Ⅱ)色心激光晶体材料(综述)

本文以KCl:Li FA(Ⅱ)心为色心激光材料的代表,从材料物理化学的角度分析了KCl-LiCl以及与基质KCl有关的掺杂体系的性质,综述了掺Li+KClFA(Ⅱ)心的主要特性,总结色心激光晶体的制备.     

氯化钾对煤矿乳化炸药爆温影响的理论计算

为研究氯化钾对煤矿许用乳化炸药爆温的影响,依据炸药爆轰理论进行了计算。结果表明,该炸药的爆热和爆温与氯化钾含量在适用范围内呈线性关系。该关系式对煤矿许用乳化炸药的配方设计具有重要指导意义。     

Performance of thermal cells and batteries made with plasma-sprayed cathodes and anodes

Cathodes for thermally activated (“thermal”) batteries based on CoS₂ and LiCl–LiBr–LiF electrolyte and FeS₂ (pyrite) and LiCl–KCl eutectic were prepared by thermal spraying catholyte mixtures onto graphite–paper substrates. Composite separator-cathode deposits were also prepared in the same manner by sequential thermal spraying of LiCl–KCl-based separator material onto a pyrite-cathode substrate. These materials were then tested in single cells over a temperature range of 400–600 °C and in 5-cell and 15-cell batteries. A limited number of battery tests were conducted with the separator-cathode composites and plasma-sprayed Li(Si) anodes—the first report of an all-plasma-sprayed thermal battery. Thermal-spraying offers distinct advantages over conventional pressed-powder parts for fabrication of thin electrodes for short-life thermal batteries. The plasma-sprayed electrodes have lower impedances than the corresponding pressed-powder parts due to improved particle–particle contact.     

Removal of Fe(III) ion from aqueous solution by adsorption on raw and treated clinoptilolite samples

Iron (III) adsorption from aqueous solutions onto raw and pretreated clinoptilolite was investigated here. Various parameters for iron removal; initial solution pH, contact time and metal ion concentration were optimized. The equilibrium data were modeled by both the Langmuir and Freundlich adsorption isotherms at optimal conditions. Adsorption capacities of raw samples and those pretreated with Na₂S₂O₈ at 20 °C , 70 °C and with HNO₃ at 20 °C were all similar but samples pretreated with HNO₃ at 70 °C were significantly different; iron (III) removal from samples pretreated with HNO₃ decreased with increasing pretreatment temperature. Tests with Fe⁺³ solutions containing phenol, CsCl or KCl, indicated the continued presence of these ions in zeolite which either promoted or retarded the adsorption of iron. The Fe⁺³ adsorption capacity of clinoptilolite pretreated with HNO₃ at 70 °C was about two times greater with, than without, CsCl and KCl. The kinetics of iron adsorption from aqueous solution were also investigated using the first-order Lagergren equation and a pseudo-second-order model.     

Numerical simulation of the B1 → B2 phase transformation in a potassium chloride sample when deformed in a gasket of a superhigh-pressure apparatus with diamond anvils

The phase transformation process in a sample of polycrystalline potassium chloride KCl when deformed under quasihydrostatic conditions in diamond anvils of a superhigh-pressure apparatus has been numerically simulated. The stages of the transformation process have been studied and the process regularities found. The phase transformation in the volume of a finite element has been shown to result in an essential redistribution of the fields of plastic and volumetric strains as well as in a decrease of the pressure in the sample, force applied to anvils and, hence, a decrease of the motive force of the transformation. During the transformation several nuclei of the new phase form in a sample, which is caused by the plastic relaxation of stresses in the B1 elastoplastically deforming phase of KCl, i.e. the formation of a new nucleus becomes more preferable than the development of the old one.     

A comparative study of hydrogen generation by reaction of ball milled mixture of magnesium powder with two water-soluble salts (NaCl and KCl) in hot water

Magnesium powder was ball milled with different weight percentages of NaCl and KCl. These mixtures were added to hot water (80 °C) and the hydrogen generation rate was measured. The results show that the hydrogen generation rate increased with an increase of the presence of both salts. Moreover, increase of the time of milling increased the hydrogen generation rate. The structure of magnesium salt mixtures was further investigated using SEM and EDS and it was demonstrated that higher hydrogen generation rate is correlated with the degree of penetration of the salt into magnesium particles. In addition, we determined that for the 15 h milled composite samples, Mg–KCl mixture generates 200 mL more hydrogen than Mg–NaCl for every 1 g Mg used. These results show that KCl salt addition is promising for hydrogen generation in presented experimental system.