Cleaning and servicing technology for turbine blade basal body surface by strong current pulsed ionizing beam

Abstract

The invention relates to a turbine blades cleaning and mending technology in maintenance engineering, which comprises the following steps: first, placing turbine blades on sample table and exposing it in strong pulsed ionizing beam; second, radiating the blades for 1-20 times with strong pulsed ionizing beam of 5-60J / cm2 to remove oxide compound; third, radiating the blades for 1-10 times with strong pulsed ionizing beam of 1-5J / cm2 to weld microcrack; forth, rotating blades and cleaning back curved face. Compared with existing technology, the invention doesn't require high-temperature and corrosion-proof equipment and produces product with smooth surface.

Description

technical field [0001] The invention relates to a technology for cleaning and maintaining the surface of a turbine blade substrate by using a high-intensity pulsed ion beam (HIPIB), and belongs to the field of equipment maintenance engineering. Background technique [0002] There are only a handful of countries in the world that can independently develop aero-engines, far less than those that can independently develop advanced aircraft. The life of turbine blades is the limiting factor that determines the performance of modern high-performance jet engines. Although these components are carefully selected during design Excellent superalloy and special cooling structure, but in the engine service process, the turbine blade is one of the weak links; with the development of the engine combustion chamber in the direction of high flow ratio, high thrust-to-weight ratio and high inlet temperature, the combustion chamber in the combustion chamber The combustion temperature and press...

AI Technical Summary

Problems solved by technology

[0002] There are only a handful of countries in the world that can independently develop aero-engines, far less than those that can independently develop advanced aircraft. The life of turbine blades is the limiting factor that determines the performance of modern high-performance jet engines. Although these components are carefully selected during design Excellent superalloy and special cooling structure, but in the engine service process, the turbine blade is one of the weak links; with the development of the engine combustion chamber in the direction of high flow ratio, high thrust-to-weight ratio and high inlet temperature, the combustion chamber in the combustion chamber The combustion temperature and pressure are constantly increasing. In order to adapt to this harsh working environment, double-layer, multi-layer and gradient thermal barrier coatings have been developed. At present, double-layer thermal barrier coatings have been put into use; however, the coating on the surface of the alloy is made of The double-layer thermal barrier coating composed of ceramic thermal insulation top layer and metal bonded bottom layer is easy to oxidize during long-term use. Oxide is formed between the substrates, and a large thermal stress is generated in the oxide, which leads to the failure of the coating along the interior of the oxide, the interface between the oxide and the metal bonding bottom layer, or the interface between the oxide and the ceramic thermal insulation top layer, so It is necessary to use a more economical and effective method to remove and recoat the failed double-layer thermal barrier coating, otherwise the high-cost blades will be scrapped due to the degradation of the coating performance, resulting in large losses; blade repair technology has become an aviation The key problems of the engine that need to be solved urgently

[0003] At present, the typical blade repair technology used is brazing repair, and the repair process is mainly: using spray stripping technology to remove the invalid ceramic insulation top layer on the blade, and the oxide between the ceramic heat insulation top layer and the metal bonding bottom layer , use chemical corrosion to remove the metal bonded bottom layer of the blade, use vacuum chemical vapor to clean the oxides formed on the surface of the blade substrate that has been in service, purify the surface of the blade substrate at high temperature in a vacuum furnace, and then undergo vacuum brazing, and the blade surface is shaped and polished , re-coat the double-layer thermal barrier coating; in the repair process, the cleaning of the surface of the blade substrate is the key technology of blade repair, and the vacuum chemical vapor cleaning used is mainly in a vacuum state, through hydrofluoric acid (HF) vapor with Al 2 o 3 、Cr 2 o 3 、TiO 2 , NiO, CoO or Y 2 o 3 The oxide reacts above 1000°C to form metal fluoride, which is heated to about 1200°C in a high vacuum furnace to volatilize the metal fluoride on the surface of the blade substrate, thereby purifying the surface of the blade substrate; but this vacuum chemical vapor cleaning process mainly has the following Disadvantages: ①Cleaning with hydrofluoric acid (HF) vapor seriously corrodes the equipment and pollutes the environment; ②The process is more complicated, involving two vacuum cleanings and two vacuum heatings

[0005] In 2000, the invention patent application of T.J.Renk et al., whose publication number is US006086726A, describes the use of energy density of 1.5 ~ 3J / cm 2 The high-current pulsed ion beam irradiates the Pt coating on the surface of the Ti substrate; the energy density is 1-4J / cm 2 The high-current pulsed ion beam irradiates the Al and Si coatings coated on the surface of the Al substrate; and the energy density is 3 ~ 4J / cm 2 The high-current pulsed ion beam irradiates the Cr coating coated on the surface of Fe and Fe-based alloy substrates, and the number of irradiations is more than 25 times to make the coating and the substrate intermix and alloy, thereby improving the mechanical properties of the substrate, but the energy is relatively low. Density of HIPIB, no ablation process occurs in alloying applications, therefore, cannot be used to clean the surface of the material

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