Production of Powdered α-Fe2O3 with Multilevel Gradient Porosity

Russian Journal of Non-Ferrous Metals - This article discusses methods for producing a material with gradient multilevel porosity by sintering layer-by-layer distributed α-Fe2O3 nanopowders...     

Reactive,nonreactive, and flash spark plasma sintering of Al2O3/SiC composites—A comparative study

The influence of different SPS-based methods, that is, conventional spark plasma sintering (SPS), flash SPS (FSPS), and reactive SPS (RSPS) on the properties of Al₂O₃/SiC composite was investigated. It was shown that the application of preliminary high energy ball milling of the powders significantly enhances the sinterability of the ceramics. It was also demonstrated that FSPS provides unique conditions for rapid, that is, less than a minute, consolidation of refractory ceramics. The Al₂O₃-20 wt% SiC composite produced by FSPS possesses the highest relative density (~99%), fracture toughness (7.5 MPa m^1/2), hardness (20.3 GPa) and wear resistance among all ceramics produced by other SPS-based approaches with dwelling time 10 minutes. The RSPS ceramics hold the highest Young's modulus (390 GPa). Substitution of micron-sized Al₂O₃ particles by nano alumina does not lead to measurable enhancement of the mechanical properties.     

Methods of reducing manganese consumption during steelmaking in a 600-ton open-hearth furnace

Karaganda Metallurgical Combine. Ural Scientific-Research Institute of Ferrous Metallurgy (UralNIIChM). Translated from Metallurg, No. 6, p. 46, June, 1988.     

Aluminized nitramine-based nanocomposites: Manufacturing technique and structure study

A technique for producing ultrafine nitramine powders and aluminized nanocomposites based on them is described. Powders of RDX, HMX, and 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (HNIWor CL-20) with an average crystal size of about 1 μm were produced by spray drying of solutions. Results of x-ray phase analysis showed that resulting nitramine was formed in an unstable crystalline phase state and the time of relaxation to an stable phase state is several tens of days. Experimental batches of explosive aluminized nanocomposites were produced by spray drying of a suspension of nanoaluminum (nAl) in a solution of nitramines with a mass content of nAl of 5, 15, and 25%. The effect of the composition of the barrier coating on nAl surfaces (an oxide coating, an organic coating based on unsaturated carboxylic acid, an organosilicon coating based on organosilazanes) and the nAl particle size on the structure of the nanocomposite product was studied. The effect of the suspension spraying conditions on the structure of nanocomposites is discussed.     

Effect of Praseodymium and Lanthanum Substitution for Bismuth on the Thermoelectric Properties of BiCuSeO Oxyselenides

Semiconductors - The  results  of  investigating  the  thermoelectric  properties of the bulk р-type oxyselenides Bi1 –xPrxCuSeO (x...     

Structural Features of High-Entropy HfTaTiNbZr Alloy Fabricated by High-Energy Ball Milling

Russian Journal of Non-Ferrous Metals - The HfTaTiNbZr high-entropy alloy (HEA) of equimolar concentration is fabricated from powder components by high-energy ball milling (HEBM) and spark plasma...     

Pressure setting mechanisms

Translated from Izmeritel'naya Tekhnika, No. 4, pp. 35–36, April, 1988.