Self-propagating high-temperature synthesis of boron subphosphide B12P2

Two new methods to produce nanopowders of B₁₂P₂ boron subphosphide by self-propagating high-temperature synthesis have been proposed. Bulk polycrystalline B₁₂P₂ with microhardness of H _V = 35(3) GPa and stability in air up to 1300 K has been prepared by sintering these powders at 5.2 GPa and 2500 K.     

Comparative study of the stress flow models for high-boron corrosion-resistant steel based on an Arrhenius-type equation and artificial neural networks

A comparative analysis is performed for the stress flow models of a steel containing 2.3 wt % B during its compressive hot deformation based on an Arrhenius-type equation and artificial neural networks. It is shown that the accuracy of the obtained data using the model based on artificial neural networks is much higher (relative calculation error is 0.2%) as compared to that of the regression model (relative error is 11%).     

Study of the structure and mechanical properties of corrosion-resistant steel with a high concentration of boron at elevated temperatures

Because of the high cost of corrosion-resistant steels, a necessary condition for their production is reducing rejection at all stages of processing, including hot forming, by optimizing process parameters. In this work, the mechanical characteristics of a corrosion-resistant steel with high content of boron have been studied at elevated temperatures. Using a special complex for the physical simulation of thermomechanical processes, it has been shown that the optimum temperature range of hot compressive plastic deformation is 950–1100°C. A mathematical model has been constructed, which relates the yield stress to the parameters of the process of hot plastic deformation. During deformation in the range of 850–1150°C, the boride particles present in the steel become oriented perpendicular to the compression axis; at high temperatures, the spheroidization of titanium diborides occurs, which reduces their size.     

The surface layers of steel machine parts after ultrasonic finishing and hardening treatment

Conclusions The physicomechanical characteristics of the surface layer of steel machine parts after ultrasonic finishing and hardening are superior to those resulting from plastic deformation by static loading or ball burnishing.Novosibirsk Electrical Engineering Institute. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 9, pp. 29–32, September, 1969.     

On melting of B4C boron carbide under pressure

The pressure dependence of melting temperatures for boron carbide and B₄C-carbon eutectic has been studied up to 8 GPa, and it was found that in both cases the melting curves exhibit negative slope (?13 ± 6 K/GPa), that is indicative of higher density of the melt as compared to the solid phase.     

RSFQ 1024-bit shift register for acquisition memory

Rapid single flux quantum (RSFQ) 512-bit and 1024-bit shift registers have been demonstrated. These are the longest superconducting shift registers reported to date, employing 1045 and 2069 Josephson junctions, respectively. The circuit functionality has been confirmed with dc bias margins of ±23% and ±14% for the 512-bit and the 1024-bit shift registers, respectively. The 512-bit shift register has been tested to 20 GHz and 1024-bit register to 19 GHz using an external clock trigger with relative delay measurements at single and double SFQ clock frequencies. The shift registers with the same design have been used for successful implementation of the acquisition shift register (ASR) memory for the projected transient digitizer. These shift registers have the ability to acquire data at high speeds (gigahertz range), statically hold the acquired data, and then read-out the data into conventional room-temperature electronics at low speeds (megahertz range). A 32-bit ASR has been tested up to 18 GHz (the limit of our test setup), and a 1024-bit ASR-up to 16 GHz of acquisition rates, both at 33 MHz read-out frequency. Total power dissipation is about 1 mW for the 1024-bit circuit. The chips are fabricated using Hypres' Nb/AlO_x /Nb process with a junction critical current density of 1.0 kA/cm ²     

The interrelation between hardness and compressibility of substances and their structure and thermodynamic properties

A strong correlation relationship has been established between the structure and specific Gibbs free energy of the substance atomization on the one hand, and the substance hardness and volume compressibility on the other. In the framework of the model proposed hardness is directly proportional to the specific Gibbs free energy per bond in isodesmic crystals. An application of a correction coefficient to the ionic component of chemical bonds allows one to evaluate the hardness of compounds having both the covalent (polar and nonpolar) and ion bonds. In the framework of the suggested approach we have been the first to correctly calculate the temperature dependence of the hardness by the example for diamond and cubic boron nitride.