V. V. Promakhov

The Application of External Fields to the Manufacturing of Novel Dense Composite Master Alloys and Aluminum-Based Nanocomposites

The possibility of producing dense and concentrated master alloys containing nanosized Al2O3 by shock-wave compacting is demonstrated. Different conditions of shock-wave process are discussed. The data of master alloys characterization are presented. The nanostructured master alloys have high density and are convenient for metallurgical handling. It is found that the use of such a master alloy with nanoceramic particles facilitates the particle introduction into the aluminum melt. The ultrasonic treatment performed during and after the introduction of the master alloy into the melt further leads to uniform distribution of strengthening nanoparticles and improvement of alloy strength and ductility. Experimental results are shown and discussed.

Thermal Shock-Resistant Ceramic Composites Based on Zirconium Dioxide1

Changes in structure, phase composition and crystal structure parameters are studied for materials of the ZrO2–MgO system after cyclic thermal shock effects. Features are revealed for formation of ceramic structure and phase condition with implementation of internal stresses connected with a sharp change in temperature. Optimum compositions are established for refractory materials based on ZrO2 answering high specifications for thermal shock resistance and refractoriness.

Self-propagating high-temperature synthesis of energetic borides

A promising way to synthesize new energy materials based on refactory inorganic compounds is self-propagating high-temperature synthesis of compositions based on boron compounds. This paper describes a laboratory technology of production of aluminum borides. The experimental results of thermogravimetric analysis and particle size analysis obtained for synthesized powders are given. According to thermogravimetric analysis data the degree of oxidation of obtained powders exceeds 95 %. The experimental data have shown that the development of new compositions of high-energy fuel cells using borides can yield high-quality results in the sphere of solid hypersonic engines.

Plasma-chemical method for producing metal oxide powders and their application

Structure and properties of ZrO2 and Al2O3 powders produced using plasma chemical technique were studied in the framework of this research. Obtained Al2O3 powder was used for reinforcement of Al alloy. Improvement of mechanical properties of Al alloy associated with introduction of alumina particles into the melt was demonstrated.

Synthesis and Properties of Energetics Metal Borides for Hybrid Solid-Propellant Rocket Engines

In this paper, the problems of production and characterization of microsized metal borides (including aluminum, titanium, magnesium) are discussed. The preferences of application for high-energy materials are presented. The problems of chemical stability and chemical compatibility are discussed. A technique for production of metal borides is also described which is known as self-propagating high-temperature synthesis (SHS) and the subsequent mechanical treatment. The result is microsized borides which have an average size of around 5 microns with a sharp curve for distribution sizes. The purity is enough for use as fuel of high-energy materials hybrid solid-propellant rocket engines. The results of SEM, X-Ray, DSC, and TG analyses are also presented and discussed.

On the possibility to fabricate ceramics using fused deposition modeling

The paper presents a uniquely designed device that enables controlled manufacturing of semi-fabricated products from thermoplastic ceramic suspensions by fused deposition modeling. Sintering of the products yields ceramics with high strength and hardness. We use ceramic aluminum oxide (Al2O3) as an example to prove that additive ceramic structures can be produced without noticeable boundaries between layers of the material.

Influence the carbon nanotubes on the structure and mechanical properties of aluminum-based metal matrix composites

It is known that metal matrix composites reinforced with non-metallic inclusions are of great interest in various fields of technology owing to a good combination strength to weight ratio. Carbon nanotubes (CNTs) are expected to be ideal reinforcements for composite materials due to their high modulus and low density. In this paper metal matrix composites were obtained through hot pressing of powder mixtures Al-1% and 5% carbon nanotubes at different isothermal time. Hardness and density of materials went up with an increase in the isothermal holding time. However, the hardness of composites decreases with an increase the nanotubes content in the material.

The Use of Alumina and Zirconia Nanopowders for Optimization of the Al-Based Light Alloys

The paper presents data on the structure, phase composition and other properties of zirconia and alumina powders obtained by electric explosion of wire and plasma-chemical deposition methods. Scanning and transmission electron microscopy reveal that the nanoscale powders are composed of spherical particles and aggregates formed by these particles. X-ray diffraction is used to identify the parameters of the crystal structure of these powders. Specific surface area is determined for all powders by BET method. Powders are used to improve the mechanical properties of aluminum alloys. For the optimization of introduction reinforcement nanoparticles used ultrasonic treatment of the melt.