Orientation and symmetry control of inverse sphere magnetic nanoarrays by guided self-assembly

Inverse sphere shaped Ni arrays were fabricated by electrodeposition on Si through the guided self-assembly of polystyrene latex spheres in Si/SiO2 patterns. It is shown that the size commensurability of the etched tracks is critical for the long range ordering of the spheres. Moreover, noncommensurate guiding results in the reproducible periodic triangular distortion of the close packed self-assembly. Magnetoresistance measurements on the Ni arrays were performed showing room temperature anisotropic magnetoresistance of 0.85%. These results are promising for self-assembled patterned storage media and magnetoresistance devices

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

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

Identification of size and concentration of submicron particles on the basis of rayleigh scattering model

A method of identification of maximum size and concentration of submicron aerosol particles based on measurement of intensity attenuation of a parallel beam of probe optical radiation is described. Offered method makes it possible to determine both particle concentration and maximum particle size with controlled accuracy for aerosol media without any initial information about particle size distribution

Study of the effect of diamond nanoparticles on the structure and mechanical properties of the medical Mg–Ca–Zn magnesium alloy

The paper addresses the production and investigation of the Mg–Ca–Zn alloy dispersionhardened by diamond nanoparticles. Structural studies have shown that diamond nanoparticles have a modifying effect and make it possible to reduce the average grain size of the magnesium alloy. Reduction of the grain size and introduction of particles into the magnesium matrix increased the yield strength, tensile strength, and ductility of the magnesium alloy as compared to the original alloy after vibration and ultrasonic treatment. The magnesium alloy containing diamond nanoparticles showed the most uniform fracture due to a more uniform deformation of the alloy with particles, which simultaneously increased its strength and ductilit

Evaluation of the possibility of obtaining welded joints of plates from Al-Mg-Mn aluminum alloys, strengthened by the introduction of TiB2 particles

In the work, the possibility of obtaining strong welded joints of aluminum alloys modified with particles is demonstrated. For research, strengthened aluminum alloys of the Al-Mg-Mn system with the introduction of TiB2 particles were obtained. TiB2 particles in specially prepared Al-TiB master alloys obtained by self-propagating high-temperature synthesis were introduced ex situ into the melt according to an original technique using ultrasonic treatment. Plates from the studied cast alloys were butt-welded by one-sided welded joints of various depths. To obtain welded joints, the method of electron beam welding was used. Mechanical properties of the studied alloys and their welded joints under tension were studied. It was shown that the introduction of particles resulted in a change in the internal structure of the alloys, characterized by the formation of compact dendritic structures and a decrease in the average grain size from 155 to 95 µm. The change in the internal structure due to the introduction of particles led to an increase in the tensile strength of the obtained alloys from 163 to 204 MPa. It was found that the obtained joints have sufficient relative strength values. Relative strength values reach 0.9 of the nominal strength of materials already at the ratio of the welded joint depth to the thickness of the welded plates, equal to 0.6 for the initial alloy and in the range of 0.67–0.8 for strengthened alloys