Effect of Hydroxide Calcination Temperature,Cold Isostatic Pressing (CIP) Pressure,and Sintering Temperature on Properties of ZrO2 + 3 mol.% Y2O3 Ceramic

ZrO₂ + 3 mol.% Y₂O₃ ceramic specimens are prepared by sintering, at 1500 and 1600°C, preforms molded from calcined hydroxide powders at 850 and 750°C using a cold isostatic pressing (CIP) technique. Bending strength and density measured as a function of the CIP pressure is shown to be quite different for specimens sintered at the two temperatures. Implications of this different behavior are discussed.     

Boron-doped diamond single crystals for probes of the high-vacuum tunneling microscopy

The results of studying the structure of diamond single crystals grown by the temperature gradient method with the aim to obtain samples having maximum uniform characteristics for manufacturing probes for scanning electron microscopes with a specified axial orientation and controlled distribution of the dopant have been considered. It has been shown that the use of similar probes in scanning tunneling microscopy decreases the probability of incidental tunneling channels with participation of the surface states caused by the presence of boron atoms in the diamond structure and increases the reliability of experimental data. The high stability of monocrystalline diamond probes and the possibility to attain the atomic resolution with the help of them have been demonstrated by the investigations of the (0001) graphite plane using scanning tunneling microscopy.     

Assessing Research and Design Costs

Russian Engineering Research - General approaches to assessing the cost of research and design are proposed. Predictive assessment of the costs is laborious and inaccurate. Accordingly, comparative...     

Structurization of Coatings in the Plasma Arc Spraying Process Using B4C + (Cr,Fe)7C3-Cored Wires

Powder Metallurgy and Metal Ceramics - The structure and phase composition acquired by coatings deposited in optimum mode by the plasma arc spraying process were examined. The spraying materials...     

Optically addressed high-resolution liquid crystal spatial light modulator with a diffraction efficiency above 50%

An optically addressed liquid crystal spatial light modulator (SLM) with a photosensitive amorphous hydrogenated silicon carbide (a-SiC:H) layer has been studied using holographic techniques. The maximum diffraction efficiency (DE) of the device amounted to η_max = 50.5%. A decrease in the DE to a level of 0.5η_max was observed at a spatial frequency of 75 mm⁻¹. The high resolution and DE of the proposed SLM are due to features in the formation of an asymmetric grating line profile in the given structure.     

Recording high-diffraction-efficiency holograms on a photosemiconductor-liquid crystal structure

Experimental real-time holograms were recorded on a structure comprising a liquid crystal and a p-i-n-diode based on a hydrogenated amorphous silicon. The holograms offer unprecedented diffraction efficiency at acceptable spatial frequencies.     

Rapid Assessment of the Cost of Product Development on the Basis of Prototype Costs

Russian Engineering Research - Express assessment of the cost of product development on the basis of prototype costs is considered. The following principles are adopted: decrease in manufacturing...     

High-strength ceramics from Zr02

Specimens of powder fabricated by codeposition of zirconium and yttrium nitrates with the using special dry ing techniques and regranulation by the method of hot isostatic pressing have been tested in air allowing for the laws of compaction of granulated powder at a final firing temperature of about 1500°C. The resulting ma terial had the following properties: a density p = 5.91 g/cm (98% of the theoretical value), an ultimate bend ing strength a = 1100 MPa, and a crack resistance K = 19.5 MPa . rn A set of the specimens was sub jected to hot isostatic pressing after natural sintering and exhibited the following properties: p = 6.08 g/cm = 1400 MPa, K = 17.5 MPa · m^1/2.