Penetration Damaging Behavior of ATI425 Titanium Alloy

The penetration damaging behavior of ATI425 titanium alloy was studied by 7.62 mm diameter armor piercing projectiles. The damage characteristics and the mechanism were analyzed by observing and analyzing the craters of ATI425 titanium alloy target. It can be found that local temperature-rise of the target plate occurred, even sputtering phenomenon in the opening stage. The shear bands extended upward along the cater wall could be seen in the stable stage. The large non-homogeneous deformation in adiabatic shear bands caused microcracks and micropores. A large number of macro-cracks were observed on the side wall and at the bottom of the crater.

Tribological and Mechanical Properties of Multicomponent CrVTiNbZr(N) Coatings

Multi-element material coating systems have received much attention for improving the mechanical performance in industry. However, they are still focused on ternary systems and seldom beyond quaternary ones. High entropy alloy (HEA) bulk material and thin films are systems that are each comprised of at least five principal metal elements in equally matched proportions, and some of them are found possessing much higher strength than traditional alloys. In this study, CrVTiNbZr high entropy alloy and nitrogen contained CrVTiNbZr(N) nitride coatings were synthesized using high ionization cathodic-arc deposition. A chromium-vanadium alloy target, a titanium-niobium alloy target and a pure zirconium target were used for the deposition. By controlling the nitrogen content and cathode current, the CrNbTiVZr(N) coating with gradient or multilayered composition control possessed different microstructures and mechanical properties. The effect of the nitrogen content on the chemical composition, microstructure and mechanical properties of the CrVTiNbZr(N) coatings was investigated. Compact columnar microstructure was obtained for the synthesized CrVTiNbZr(N) coatings. The CrVTiNbZrN coating (HEAN-N165), which was deposited with nitrogen flow rate of 165 standard cubic centimeters per minute (sccm), exhibited slightly blurred columnar and multilayered structures containing CrVN, TiNbN and ZrN. The design of multilayered CrVTiNbZrN coatings showed good adhesion strength. Improvement of adhesion strength was obtained with composition-gradient interlayers. The CrVTiNbZrN coating with nitrogen content higher than 50 at.% possessed the highest hardness (25.2 GPa) and the resistance to plastic deformation H3/E*2 (0.2 GPa) value, and therefore the lowest wear rate was obtained because of high abrasion wear resistance.

INFLUENCE OF PRELIMINARY ULTRASONIC PROCESSING OF VT6 TITANIUM ALLOY ON THE STRUCTURE OF A SURFACE LAYER AFTER IMPLANTATION

The article presents a study on the implantation of silver titanium alloy VT6. It has been shown that ion implantation contributes to the creation of compressive stresses in the surface layer of the target, which makes it possible to increase the endurance indices of the processed alloy under alternating loads. Ultrasonic processing leads to the formation of a nanostructured layer on the surface of a VT6 alloy target. As a result of ultrasonic impact treatment, the structure of the surface layer undergoes significant changes.

Влияние фазовых превращений на взаимодействие алюминиевых сплавов при скоростях более 9 km/s

The introduction of an aluminum jet with a speed of 8 - 11 km / s into an aluminum alloy target is being investigated. An analysis of the kinetics and parameters of penetration, the surface of the cavity after the introduction suggests that at speeds of more than 9 km / s the hydrodynamic nature of the penetration is violated due to the melting of interacting metals. The results of the study are intended to develop screen protection of spacecraft from the most dangerous fragments of space debris.

Effect of substrate temperature on structural and thermoelectric properties of RF magnetron sputtered SnSe thin film

SnSe is a potential thermoelectric material, but there are few reports about the thermoelectric properties of the film. In this work, SnSe thin films were deposited on glass substrates by RF magnetron sputtering from SnSe alloy target. The effect of substrate temperature on the structural and thermoelectric properties was investigated. It was found that the columnar grains and the surface roughness of the films increase with increasing the substrate temperature. The film deposited at 558 K exhibited a high crystalline quality and stoichiometric composition, which has a maximum power factor of 1.4[Formula: see text]uWcm[Formula: see text]K[Formula: see text] at 575[Formula: see text]K. The results of this work demonstrate the importance of high substrate temperature to obtain high thermoelectric performance SnSe films.