Erosion of Vacuum-Arc Ti–N Coatings

We studied the fracture of vacuum-arc Ti–N coatings, produced under a nitrogen pressure (P _TiN) from 1 to 10³ mPa, after their bombardment with polyenergetic deuterium ions and the action of cavitation in tap water on them without ion irradiation. We showed that, in the case of action of cavitation on nonirradiated specimens of the coatings, their erosion rate can be evaluated from the relation V _c = C/(W ^0.75 H ^0.5). It was established that, after ion bombardment, the erosion rate under conditions of cavitation decreases by a factor of 1.5 for coatings where P _TiN > 100 mPa and increases by more than 30 times for P _TiN < 20 mPa as compared with nonirradiated specimens. The results obtained were analyzed using the phase diagram of the titanium-nitrogen system.     

Interfacial Electrical Properties of Nanodiamond Colloidal Species in Aqueous Medium as Examined by Acid-Base Indicator Dyes

This study was aimed at further examining of a detonated nanodiamond hydrosol, produced by the NanoCarbon Research Institute, Japan. In the concentrated solution, this colloidal system consists mainly of 3 nm-sized primary particles. These particles are positively charged and tend to associate into larger colloidal species on dilution. The species adsorb, first of all, the anionic dyes and readily coagulate on adding electrolytes. Some properties of the sol are changed during prolonged ageing but may be restored by adding small HCl amounts. Besides measuring the electrokinetic potential, the interfacial electrical potential was estimated by using acid-base indicators.     

Interrelation between the cavitation resistance and microhardness of metals

Under the action of cavitation induced by an ultrasonic vibrator in tap water, we determine experimentally the level of fracture of transition metals that belong to Groups IV—VI of the periodic table. It is shown that the cavitation resistance of the metals is determined by the microhardness with an error of ±10%. For the preliminary assessment of the cavitation resistance, we can use the relation Z _h = 2.42 ∙ 10^-2 H _μ³, where the microhardness is determined in GPa.     

Resistance of Tungsten-Rhenium Alloy under the Action of Microimpacts

We determined the resistance of specimens of tungsten and V3K alloy to abrasive and cavitation wear with respect to VR-27VP alloy. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 41, No. 4, pp. 121–122, July–August, 2005.     

Cavitation resistance of cold-worked steels and copper

We have studied the cavitation resistance of 15Kh11MF steel and copper after low-temperature (∼ 300 K) deformation by rolling, program loading, ultrasonic treatment, and equal-channel multiangle pressing. We have established that the cavitation resistance grows by no more than 50% as a result of ultrasonic treatment, program loading, and rolling at 77 K of 15Kh11MF steel and equal-channel multiangle pressing of M1 copper. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 43, No. 3, pp. 89–92, May–June, 2007.     

The impact of temperature on the degree of structurization of water of different isotope composition

Using vacuum ultrafiltration radiation and the method of dynamic light scattering employing samples of light (D/H = 6 ppm), distilled (D/H = 150 ppm ) water and the water with an increased content of deuterium (D/H = 7700 ppm, 99.96%) as an example within the interval 4–80°C the impact of temperature on the degree of water structurization of the different isotope composition was studied. Experimentally has been established the sizes of optical inhomogeneties of studied waters at various temperatures. It has been shown that temperature relationships of these types of water obtained by these methods have a graded nature with clear-cut critical points at 4; 36; 45 and 60–70°C.     

Cavitation-induced fracture of a vacuum titanium coating

Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 30, No. 5, pp. 90–92, September–October, 1994.     

Cavitation resistance of modified surface layers of alloyed steels

The cavitation strength of 15Kh11MF and 15Kh12VNMF steels after nitriding and deposition of vacuum arc titanium and titanium nitride coatings is investigated. Kinetic curves of fracture of specimens under the action of cavitation and polarization curves in a 3% aqueous solution of NaCl are obtained, and the microhardness is measured. A steel–coatings system is thermocycled by the scheme 293 K–543 K–293 K with cooling in a 3% NaCl solution. The serviceability of the system is confirmed.