STUDIES OF PROCESSES OF THE PRECURSOR FORMATION FOR PRODUCTION OF CuAlO NANOCERAMICS AT THE EFFECT OF DOUBLE LASER PULSES ON AD1 AND M2 ALLOYS IN THE AIR ATMOSPHERE

Проведено исследование процессов образования смешанных нанопорошков Al, оксидов меди и алюминия, прекурсоров для получения нанокерамик типа CuAlO и CuAlO при воздействии сдвоенных лазерных импульсов энергией 53 мДж и между импульсным интервалом 10 мкс на мишень, состоящую из пластинок алюминия марки АД1 и меди марки М2, склеенных между собой и помещенную в закрытую стеклянную прямоугольную кювету. Установлено, что последовательное воздействие серий сдвоенных лазерных на мишень из алюминия, а затем на мишень из меди приводит к многократному увеличению выхода субоксидов AlO, ионов и атомов алюминия и меди в лазерном факеле, направляемом на подложку, при напылении пленок, по сравнению с воздействием одиночными лазерными импульсами. Изучены процессы, происходящие на поверхности подложки при напылении пленок. Показана возможность получения прекурсоров для получения нанокерамик типа CuAlO и CuAlO. A study of formation of mixed Al nanopowders, copper and aluminum oxides, and precursors for production of CuAlO and CuAlO nanoceramics under the influence of double laser pulses with energy of 53 mJ and the interpulse interval of 10 microseconds on a target consisting of plates of aluminum grade AD1 and copper grade M2, 0,4 mm thick, glued together and placed in a closed rectangular glass cuvette. It is found that the successive exposure of a series of double laser beams to an aluminum target and then to a copper target leads to a multiple increase in the yield of AlO suboxides, aluminum and copper ions and atoms in the laser torch, compared with the exposure to single laser pulses. To better understand the hidden mechanisms of this dependence, we study the processes occurring both on the surface and in the near-surface laser plasma inside the resulting microchannel when the target is broken by a series of single and double laser pulses. The possibility of obtaining precursors for the production of nanoceramics such as CuAlO, CuAlO is shown.

Aluminum Oxide Catalysts and Supports Obtained by Thermal Activation

The paper considers the main methods used to obtain aluminum oxides; the advantages of using hydrargillite thermal activation products for the synthesis of catalysts, supports and sorbents; the factors affecting the properties of thermal activation products and aluminum oxides obtained by thermal activation; and examples of the efficient application of hydrargillite centrifugal thermal activation products in the synthesis of catalysts, supports and sorbents.

A Review on the Role of Amorphous Aluminum Compounds in Catalysis: Avenues of Investigation and Potential Application in Petrochemistry and Oil Refining

Aluminum oxides and hydroxides are widely applied because of the great variety of their modifications. In particular, aluminum oxides and hydroxides are used in petrochemistry and oil refining. However, amorphous aluminum compounds have not been sufficiently studied due to the complexity of their synthesis and the problems encountered during their study. The study of amorphous aluminum compounds is hindered by the ambiguity of terminology. In this work, the structures of amorphous aluminum compounds prepared by different methods and the properties that determine their applications have been highlighted in detail. Amorphous aluminum compounds play both positive and negative roles in petrochemistry; however, in petroleum refining, amorphous compounds (without promoters and transition metal salts) demonstrate a promising catalytic performance in oil upgrading.

Interaction of rail steel melt with refractory lining

The rail steel properties are adversely affected by rigid non-metallic inclusions, containing aluminum oxides. Therefore, aluminum content is limited to 0.004 % wt. in rail steel grades. Aluminum can get into steel from charge materials and refractory lining. In this work, we’ve analyzed how the chemical composition of refractories used in rail steel making influence steel quality on example of one domestic enterprise. To determine the main types of non-metallic inclusions created in E76F rail steels, we have performed fractional gas analysis of the samples taken in various process steps. It was found that the slag composition after degassing changes insignificantly, while the most part of non-metallic inclusions in rail steel is represented by aluminates.

Plasma way to obtain ultrafine iron and aluminum oxides

The paper deals with two plasma-chemical synthesis installations based on alternating cur-rent plasma torches with power up to 30 kW, which can be used for production of ultrafine (nanosized) oxide and carbide materials. Some results obtained during experimental studies on the production of ultrafine powders of metal oxides (iron and aluminum) are presented.

The Dynamics of Tungsten in Soil: An Overview

The increasing use of tungsten in the production of green energy in the aerospace and military industries, and in many other hi-tech applications, may increase the content of this element in soil. This overview examines some aspects of the behavior of tungsten in soil, such as the importance of characteristics of soils in relation to bioavailability processes, the chemical approaches to evaluate tungsten mobility in the soil environment and the importance of adsorption and desorption processes. Tungsten behavior depends on soil properties of which the most important is soil pH, which determines the solubility and polymerization of tungstate ions and the characteristics of the adsorbing soil surfaces. During the adsorption and desorption of tungsten, iron, and aluminum oxides, and hydroxides play a key role as they are the most important adsorbing surfaces for tungsten. The behavior of tungsten compounds in the soil determines the transfer of this element in plants and therefore in the food chain. Despite the growing importance of tungsten in everyday life, environmental regulations concerning soil do not take this element into consideration. The purpose of this review is also to provide some basic information that could be useful when considering tungsten in environmental legislation.