When countries around the world hold celebrations, military parades or aviation exhibitions, often have to perform aircraft smoke performance. The working principle of smoke pulling is that the smoke pulling nozzle is connected with the low-temperature smoke pulling agent storage box with certain pressure through the pipe, the smoke pulling nozzle is fixed or suspended at the end of the jet engine nozzle, and the high temperature near the engine nozzle is used to make the smoke pulling agent vaporize instantly, and then it is ejected through the nozzle to achieve the purpose of smoke pulling. With the development of aviation industry, the emergence of high-performance aircraft, which is used in the aircraft materials also put forward higher requirements. In the past, China's performance models were mainly J-7 fighter jets. The maximum temperature of the tail of the engine nozzle during the aircraft's afterforce was 1400°C, and the temperature during the steady flight was less than 1000°C. The material used for the nozzle was GH420 and nickel based superalloy.
The performance aircraft used now is j-10 fighter jet. The temperature near the nozzle of the engine can reach 1700°C when the aircraft is in afterforce. The superalloy material originally used by its smoke nozzle cannot be used due to serious burning damage when it is used in this type of aircraft. So there is an urgent need for a more suitable for the new performance machine engine nozzle environment to replace the original smoke nozzle. Once installed on the performance aircraft, the nozzle is in service. During the flight of the aircraft, it not only has to bear the scour effect of high temperature and strong airflow, but also has to be subjected to the cooling effect of smoke pulling agent, which requires the nozzle to have excellent high temperature (1700°C) antioxidant performance, sufficient high temperature strength and good thermal fatigue performance. In addition, from the consideration of safety, the smoke nozzle in the use of the state should have good toughness, not brittle fracture. At 1700 ° C of the development process of smoke nozzle, used carbon fiber ceramic, tungsten copper and nickel based high temperature alloy surface layer made of zirconium dioxide, but carbon fiber ceramic because due to the effect of heat and strong current and easy to brittle fracture, tungsten copper materials in high temperature molten copper can clog the nozzle mouth, coated nickel base superalloy cannot bear the high temperature effect of a long time, and the damage is serious.
The utility model adopts the technical scheme is a kind of aircraft flight performance with niobium alloy smoke nozzle, and its characteristics including made from Nb521 alloy bars and the nozzle body with air flow channel of smoke, smoke described pull one end of the nozzle body end outside wall car install screw, smoke referred to pull the other end of the nozzle body end runs of smoke groove is connected with air flow channel, described the inner surface of the smoke flow channel and the slot and pull smoke nozzle body remove the thread on the surface are coated with high temperature oxidation resistance coating. The above mentioned niobium alloy smoke nozzle for an aircraft flight performance is characterized in that the high-temperature anti-oxidation coating is niobium alloy high-temperature anti-oxidation coating.
