NEW IDEAS IN AIRCRAFT ENGINE MANUFACTURING: WELDING (сварка)
ПОЯСНЕНИЯ К ТЕКСТУ
1. joining techniques - методы соединения (отдельных элементов конструкции в подсборку или узел)
2. constituent weight - вес компонентов двигателя (лопатки, колеса компрессора и турбины, вал, агрегаты и т. д.)
3. thermo-mechanical handling - термо-механический режим обработки
4. fine manufacturing tolerances - жесткие допуски при изготовлении
5. higher energy density, lower heat consumption - более высокая плотность подводимой энергии, меньший расход тепла
6. solid joining processes - процессы выполнения неразъемных соединений
7. programmable process control and monitoring - программное управление технологическим процессом и контроль за его ходом
8. tungsten-inert gas welding - сварка вольфрама в атмосфере инертного газа
9. plasma welding - плазменная сварка
10. electron beam welding - электроннолучевая сварка
11. flywheel-friction welding - сварка трением за счет выделения энергии, запасенной в маховике
12. guidance mechanism - направляющий механизм, производящий подачу свариваемой детали
13. to contain the required tolerances for the axle unit and the welding upset - сократить требуемые допуски для осевого агрегата и на высадку изделий в результате расплавления свариваемых торцевых участков
14. diffusion welding - диффузионная сварка, происходящая путем взаимопроникновения (диффузии) молекул в кристаллические решетки
I. Joining Techniques
Joining techniques are of considerable importance in engine manufacturing methods, since, by analysing complex engine structures, it is possible to realize space-saving designs (компактные, малогабаритные конструкции), reduce component weight (вес деталей) and lower production costs. The employment of joining techniques, however, involves the solution of a number of specific problems. 80 per cent of engine constituent weight is made up of superalloys of the nickel or cobalt type, as well as titanium alloys, which need a particular type of thermic or thermo-mechanical handling. Their utilization requires fine manufacturing tolerances and places high demands on reliability (требует высокой надежности). One aim of developing new joining techniques in engine manufacturing is to introduce welding processes with higher energy density and lower heat consumption. Another aim is to introduce solid joining processes, which would allow the possibility of a programmable process control and monitoring.
Welding procedures with medium energy density and heat consumption such as tungsten-inert gas welding and plasma welding, are mainly employed today for dynamically stressed (динамически напряженный) components such as housings (корпус, кожух), containers and afterburner parts (элементы камеры догорания).
II. New Welding Procedures
Electron beam welding is employed almost exclusively for statically and dynamically stressed (статически и динамически напряженные) components such as discs, shafts (вал,ось, шпиндель), and gearwheels (зубчатое колесо). One problem with electron beam welding is the danger of pore formation (образование пор) and of microcracks (микротрещины) in nickel alloys. It now appears possible that these faults (дефекты) can be prevented by improving material structure and beam control (регулирование луча).
Flywheel-friction welding is limited to rotationally symmetrical components (ротационно симметричные). This method is employed exclusively for joining shafts and gear wheels. Work is now in progress on the possibility of flywheel-friction welding of much larger components, such as high-pressure compressor rotors (ротор компрессора высокого давления). Previously, the extremely high pressure and kinetic energy involved necessitated the use of a complicated guidance mechanism for the components during welding. Now it is possible, however, to contain the required tolerances for the axle unit and the welding upset. This development of the flywheel-friction welding procedure represents an alternative to the developments in electron beam welding methods described above.
Diffusion welding can be carried out with or without an intermediate layer (промежуточный слой, покрытие). Diffusion welding with an intermediate layer differs in the degree of diffusion of high temperature solder (твердый, тугоплавкий припой). This process holds great promise for producing turbine blades with improved cooling systems.