Рассмотрено применение вероятностных моделей деформирования и разрушения композиционных материалов с хрупкой матрицей с учетом макродеформаций для квазиоднородного материала с микронеоднородностью. Для оценки эффективности предложенных моделей деформирования и разрушения хрупкого керамического материала и отработки методики на примере лопатки турбины высокого давления малоразмерного газотурбинного двигателя решена контактная задача. Ключевые слова: вероятностная модель деформирования, керамические композиционные материалы, контактная задача, напряженнодеформированное состояние, технологические поры.

Modifying the working surface of a product by applying protective and functional coatings makes possible considerable changes in the mechanical, optical, electrical, magnetic, thermal and chemical properties of the original structural material, its real surface, producing articles with protective, for example, anti-corrosion, wear-resistant and other properties. We investigated the possibility of improving the friction units of aircraft power plants by applying nanostructured ceramic composite spray coatings. A heavily loaded bearing forming a part of the gearbox of a turbojet engine is used as a prototype of the friction unit. The advantages and drawbacks of improved friction units as compared to production models and their prototypes made according to an improved technology are assessed. The results obtained during the experimental work are presented. A positive conclusion is made about the use of nanostructured composite materials in the development of friction units; the most favorable method of coating is determined.

The article describes surface hardening of aircraft engine titanium-alloy hydraulic cylinder face using the method of electro-spark doping by low-energy discharges. Graphite electrodes were used to provide functional behavior of the cylinder surface layer. The carbon oxide layer formed has a highly dispersed structure of a complex composition (with particles of titanium carbide, titanium oxide, graphite), 3-10 micron thick, characterized by high hardness and sliding properties. Graphite electrode alloying practically does not change the part dimensions. Subsequent diamond burnishing of the hardened surfaces decreases the value of the friction coefficient and surface roughness. Healing of defects and micro-cracks improves the fatigue resistance of the part. The developed technology makes it possible to assure the characteristics required of hydraulic cylinder work surfaces and increase their life.

Представлена расчетная оценка параметров одного из спроектированных подшипников скольжения и его модели с антифрикционным покрытием карбонитридом титана. Проведено планирование экспериментальных работ по результатам расчета параметров разработанной модели. Приведены результаты испытаний данного подшипника.

A method has been developed for calculating the pressure distribution in a cylindrical slide bearing. We present the process of designing a heavy-duty slide bearing as a component of the reduction gearbox of a bypass turbojet engine as the object of our investigation. The process comprises the following stages: specification of the supporting structure; calculation of pressure distribution in the slide bearing for different eccentricities and angles of rotation of the shaft journal; calculation of the effect of shaft journal precession on pressure distribution; calculation of pressure distribution taking into account the channels of oil supply to the bearing. The results obtained in the experimental activities are given. The analysis carried out shows that the calculation helps to predict the location and size of pressure and rarefaction areas, to position the holes for oil supply, which will significantly improve the conditions of lubricant flow in the bearing.