Selection of Nanostructured Zirconium Dioxide Crystals under Dry Friction against Molybdenum

The article considers the issues of contact interaction of nanostructured zirconium dioxide crystals with molybdenum coating on titanium-based alloy ВТ9. The following statement is substantiated: the best mechanical properties of crystals correspond to the total amount of 2.8% additives of stabilizing and doping rare earths elements. Antifriction properties of crystals under dry friction against molybdenum are investigated. Tribological testing was performed on a reciprocating friction gauge simulating the operation of a plunger in a cylinder. The high scoring resistance of the friction couple under study was experimentally proved; the friction coefficient did not exceed 0.07. On the basis of the study performed, the friction couple is defined as promising for increasing the lifetime and reliability of friction units for hydraulic equipment and fuel pumps.

Tribological Properties of Sapphire under Dry Friction against Chromium and Zirconium Ceramics

The issues of sapphire friction and wear in contact with chrome steel and zirconium ceramics are discussed in this article. The kinetic microindentation method is used to study the mechanical properties of sapphire in frictional contact in modelling experiments on the indentation of a Vickers indent. Taking into account the anisotropy of the mechanical properties of sapphire, the influence of the load and orientation of the indent on the modulus of elasticity and hardness is analyzed. It has been established that, under dry friction conditions it is promising the use of zirconium ceramics in the supports of devices operating under conditions in which the use of lubricants is impossible. The possibility of using a friction couple of sapphire-zirconium ceramics in friction units operating in open space is noted.

Improvement of the tribological properties of heavy-loaded friction units “Centre block-footstep bearing” of a freight car

Various problems and different approaches of solution of such a problematic unit as “centre block-footstep bearing” of freight cars are discussed in the paper. The methods of improving the tribological properties of this friction unit by means of material modification of friction surfaces and perfection of physical, chemical and tribological properties of the used lubricants were studied. Grease lubricants common for friction units of railway machinery were used after being modified with inorganic polymers based on double metaphosphates. Bench and operational tests of the developed additive of the polymeric double metaphosphates were carried out. This additive reduces wear and increases the service life of the friction unit, due to the better adhesion properties of this additive. The variants with a change in the geometry of the contact surface of the disk between the bolster and the “centre block-footstep bearing” arrangement of the car are considered. Simulation of the parameters of movement in curved sections is proposed.

Methods for increasing the wear resistance of heavy loaded metal-polymer tribosystems

Methods of increasing the wear resistance and reliability of friction units are generating considerable interest being a vital factor in transport, mechanical engineering, and other fields of technology. The solution of the given problem is impossible without the creation of self-regulating structures on the friction contact surfaces. We strongly believe that this problem can be solved by creating multicomponent functional layers (hereafter MFL) on tribocontact.

The prospects and scientific solutions for the application of the innovative technologies to create vacuum-levitation vehicles

The elevated transport system is currently being challenged to increase speed. Of course, Russia is facing this problem because of its vast territory connecting the economic centers of the European Union - the North American continent - Southeast Asia. The answer to this challenge is the vacuum-levitation transport system (hereinafter VLTS), which significantly increases the speed of freight and passenger traffic. In fact, you can list many more tasks when creating VLTS - these are issues of safety, earthquakes, landslides, floods, karsts and others, but we will focus on the field of chemistry and the sciences of composites, which will be the subject of this article. When developing VLTS, it is necessary to determine the behavior and reliability of friction units - this is a braking system, a center plate - a thrust bearing, a reducer, etc. The fundamental difference between tribocontact surface layers operating in air and vacuum is that oxide films are formed during friction in a gas environment and thus there is no contact between juvenile surfaces, and in a vacuum, juvenile surfaces are seized, which leads to intense wear. The article presents a technology for increasing the wear resistance of metal-polymer friction units, taking into account the properties of polymer composites to form secondary structures on the friction surface.

TECHNOLOGY OF DEPOSITION OF COATINGS FROM HARD ALLOYS ON THE WORKING SURFACES OF FRICTION UNITS

A technology has been developed for applying explosively to the surface of centrifugal pump parts for pumping overheated distillate under NPP conditions of hard alloy coatings of the CrC-Ti system, which ensures high hardness of the coatings and the strength of their connection with the surface to be coated, and the best tribotechnical materials in comparison with existing materials friction characteristics against siliconized graphite in water.

Deposition of a titanium carbonitride coating by magnetron sputtering on a substrate with a potential voltage

Titanium carbonitride (TiCN) is of high relevance in the field of creating wear-resistant protective coatings in order to ensure maximum wear resistance and service life of parts of friction units. Titanium carbonitride coatings were obtained by magnetron sputtering at various bias substrate in the range from 0 to -130 V with a step of 10 V. The effect of the bias substrate on the deposition rate, phase and elemental composition, and the friction coefficient of the obtained coatings was investigated. As a result of the obtained dependences, the most optimal mode of deposition by the method of reactive magnetron sputtering with a negative bias voltage on the substrate was determined.

High-temperature friction units with carbon-containing materials

The frictional interaction of carbon-carbon composites with steel at high temperatures is considered. Antifriction properties of carbon composites are investigated at friction on a steel at speeds of 0,050,25 m/s and pressures of 0,31,0 MPa. The advantages of Hardcarb-T material in comparison with Argalon-2D material are experimentally determined. Keywords: temperature, friction, contact pressure, composites, steel, speed, friction coefficient. [email protected]

Aluminum Composite Materials Providing Extended Service Life

Hardness and tribotechnical characteristics were investigated under conditions of dry sliding friction on steel obtained by liquid-phase mixing of Aluminum-Matrix Composite (AMC) materials based on aluminum alloys AK12, D16, V124, AL9, AL25, reinforced with silicon carbide SiC particles with a size of 28 μm with a content of 5, 10 or 15% by volume. AMC performed better than matrix alloys and the commonly used antifriction aluminum alloy AOM 2-1. The dry friction coefficient was 1.5-3 times lower on average, and the volumetric wear rate was 5-9 times lower. An increase in the content of SiC particles in the composite from 5 to 20 vol.%. As a rule, leads to an improvement in the tribotechnical characteristics. The composites obtained have shown a sufficiently high operational suitability for work in friction units with steels both in dry friction and in friction with lubrication.