ПЕРСПЕКТИВЫ ИСПОЛЬЗОВАНИЯ КОМПОЗИЦИОННЫХ МАТЕРИАЛОВ ДЛЯ ЛОПАТОК ГАЗОТУРБИННЫХ ДВИГАТЕЛЕЙ

Морозов М.В.¹, Вайтайтис В.В.², Головина Н.Я.³

¹Студент; ²студент; ³кандидат технических наук, доцент, Тюменский государственный нефтегазовый университет,

филиал в г. Сургуте

ПЕРСПЕКТИВЫ ИСПОЛЬЗОВАНИЯ КОМПОЗИЦИОННЫХ МАТЕРИАЛОВ ДЛЯ ЛОПАТОК ГАЗОТУРБИННЫХ ДВИГАТЕЛЕЙ

Аннотация

В статье проведен анализ повреждений лопаток газотурбинных двигателей (ГТД).  Сформулированы требования к материалам лопаток. Исследованы возможности применения композитов в качестве материала лопаток.

Ключевые слова и фразы: разрушение, лопатки, ГТД, композитные материалы.

Morozov M.V.¹ Vaytaytis V.V.², Golovina N.Y.³

¹Student; ² Student; ³Candidate of Technical Sciences, Docent, Tyumen State Oil and Gas University, branch in Surgut

PROSPECTS OF COMPOSITE MATERIALS FOR GAS TURBINE ENGINE BLADES

Abstract

The article analyzes the damage of blades of gas turbine engines (GTE); the requirements to the materials of the blades; the possibilities of application of composites as a material of blades.

Keywords: fracture of a blade, GTE, composite materials.

Reliable operation of gas turbine engines (GTE) largely depends on their blading work abilities. One of the most promising ways of increasing the technical characteristics of the GTD is the use of composite materials (CM).

In this sphere, there are some important researches with one aim: creating a composite compressor blades and power turbine, the use of which increases the reliability of the engine and significantly reduces its mass. That will noticeable increase the productivity of the energetic-producing process.

For the material of high pressure turbine blades (HPT) and a low pressure compressor (LPC) - surely have different requirements for their working conditions.

For the HPT blades characterized by the following defects:

- Burnout - is a consequence of the high-impact gas flow (approx. 900 ° C);

- Nick - traces of contact with the blades of fragments of another parts of the turbine;

- Cracks - the result of mechanical or thermal fatigue;

- Breakage of the blade due to foreign objects;

- Cleavage of a coating due to mechanical and thermal effects of the gas stream;

- Erosion - the result of the oxidation of nickel alloys at high temperatures under the growing influence of aerodynamic gas stream;

- Sulfur-oxide corrosion - chemical decomposition of the metal due to interaction with the environment.

The main defect of the CPV blades are corrosion and mechanical damage as a result of entering into the working area of foreign objects.

Vane material must withstand the staining and temperature for a long time.

In the design of modern turbine engine blades for CPV titanium alloys used for the manufacture of the blades of the HPT , nickel-based alloys are widely used , what, unfortunately, does not allow much to raise the temperature in the GTE without reducing the service life of the turbine.

Since the middle of 20th century and still, the creation of composite materials for the manufacture of gas turbine engine blades is leading. Many outstanding scientists  are trying to create the composite.

The composite is an artificially created inhomogeneous solid material consisting of two or more components with a clear boundary between them.  In most composite components can be separated by the matrix and incorporated there in reinforcements. The reinforcement elements typically provide the necessary mechanical characteristics of the material (strength, stiffness etc.), and the matrix provides reinforcement elements work together and protect them from mechanical damage and corrosive chemical environments.

Composite materials are classified according to the following main characteristics:

- The matrix material and the reinforcing elements;

- The geometry of the components, structure and layout of the components;

- On the method of manufacture.

According to the location of the reinforcing filler:

- Fibrous (reinforcing component - the fibrous structure);

- Layered;

- Full of plastic materials (reinforcing components - particles);

- Bulk (homogeneous);

- Skeletal (primary structure, filled with binder).

According to the material of the matrix:

- Composites with polymeric matrix;

- Composites with a ceramic matrix;

- Metal matrix composites;

- Composites oxide-oxide.

Reinforcement material may be different, depending on the properties required. As a material of reinforcement metals, fiberglass, basalt, carbon fiber (carbon fiber), and others are used always.

The first attempt to put the composite blades undertook Rolls Royce in the second half of 1960. But composites of those times were not able to provide sufficient strength and impact reliability.

Creating composite blades, superior titanium, became possible recently with the advent of new materials. Rolls-Royce and General Electric in the manufacture of blades use similar technology. The blade is formed of a number of pre-impregnated "webs" of the fiber.

A French man - Laep-X began to use the technology 3D resintransfer moulding - creating a three-dimensional structure of a single fiber, which later becomes impregnated filler and goes "ripen" into the autoclave. Bulk structure allows for greater strength.

The advantages of composite blades are:

- High specific strength (up to 2500-3000 MPa)

- High stiffness (modulus of elasticity of 140 GPa, 130 ...)

- High wear resistance

- High resistance to fatigue

- Possibility of producing dimensionally designs

Moreover, different classes of composites can possess one or more advantages. Some benefits can not be achieved simultaneously. Application of new blade significantly reduces the weight of the engine.

Potential disadvantages of composite materials include:

- Low toughness;

- High cost;

- Hygroscopicity;

- Toxicity;

- Low maintainability.

A feature and an advantage of the composite materials is that combining different materials possible to achieve the properties which are needed for these conditions.

After examining the properties of various types of composite materials, the author concluded: - many composite materials have the necessary qualities for modern improvements of GTE. One of the directions of further improving the reliability and performance of the GTE is undoubtedly associated with the use of new composite materials.

For the HPT blades, taking into account the working conditions, the most suitable metal-ceramic composites. Physical properties include metal ductility, high strength and high thermal conductivity. Ceramics has such basic physical properties such as high melting point, chemical stability and, in particular, resistance to oxidation. These blades are lighter than steel and can speed up the layout.

For the manufacture of blades CPV most suitable polymeric composite materials (PCM) [3]. PKM has a unique combination of properties is not characteristic of other materials: high static and impact strength, elasticity, resistance to corrosion is possible to control the properties of PCM by slight changes in the composition and the preparation conditions. Significant advantage of the polymeric materials are the relative ease of processing and relatively low density.

In solving the problem of creating a new generation of GTE the new heat-resistant composite materials play the leading role.

References

1. Васильев В.В., Добряков А.А., Молодцов В.А. Основы проектирования и изготовления конструкций летательных аппаратов из композиционных материалов: учеб. для вузов. – М.: МАИ, 1985. – 218 с.
2. Каблов Е.Н. Новые материалы и технологии – определяющий фактор развития авиационной техники // Технологические системы. – 1999. – №1. – С. 27 – 29.
3. Раскутин А.Е., Гуняев Г.М., Румянцева А.Ф. Термостойкие углепластики для применения в газотурбинных двигателях // Композиционные материалы в промышленности: тезисы докл. Междунар. Конф. (Ялта, 2 – 6 июня 2003 г.). – Ялта, 2003. – С. 94.