CN1361308A - Ionic TiALN coating for blade of air compressor in naval aircraft engine - Google Patents

Abstract

The invention relates to a metal surface coating technology, specifically using a coating machine, using composition modulation and process parameter control methods, using the difference in the melting point and vapor of plating materials titanium and aluminum, and the difference in reactivity to control the deposition parameters to form Al- (Ai, Al)-TiN non-interface gradient coating. Advantages: Using composition modulation and process parameter control, the problems such as pinholes and voids that hinder the application of ion-plated TiN coatings in the anti-corrosion field are solved without the need for equipment modification.

Description

Ion Plated TiAlN Coatings for Naval Aeroengine Compressor Blades

The invention relates to a metal surface coating technology, which is suitable for the coating of naval aeroengine compressor blades.

Naval aviation planes work in the ocean environment all the year round, fly on the sea or park on ships. Due to the humidity and high salt content of the ocean atmosphere, the condensation of water molecules and the active Cl ^- ions cause corrosion of aircraft materials. It is also affected by dynamic and static loads during parking and flight. Under the interaction of corrosion and mechanical factors, the service life of aircraft components is greatly reduced, which poses a great threat to safe flight. Therefore, effective protection methods are used to improve aircraft components. Service life has become a very attractive research direction in the development of aviation industry.

Compared with the above-mentioned components that work in the humid and high-salt marine atmosphere, the working environment of the exhaust compressor blades of naval aviation aircraft engines is even harsher. Many of the compressor blades are made of 1Cr11Ni2W2MoV stainless steel , while the working temperature of the latter blade of the compressor is between 300 and 600°C. In the normal dry atmosphere, this kind of stainless steel has better corrosion resistance, because the surface of 1Cr11Ni2W2MoV stainless steel is at a higher temperature. A layer of dense Cr ₂ O ₃ oxide layer is formed, which prevents further oxidation of the material. However, for naval aeroengines, not only the operating temperature is high, but also the combined effects of mechanical factors such as water vapor, active Cl ^- ion corrosion, and dynamic and static loads. , the comprehensive effect of water vapor and salt has a strong destructive effect on the oxide film, resulting in rapid corrosion and oxidation of the compressor blades in a short period of time, resulting in the failure of the compressor blades to work normally, which has a great impact on flight safety.

There are many surface modification processes for aero-engines, but the protection of the rear-stage blades of aero-engine compressors in the marine atmosphere has not been resolved. The ion-plated TiN coating has good wear resistance and erosion performance due to its high hardness. It is mainly used in the hard transition layer of cutting tools and molds. Due to the existence of defects such as pinholes and voids, its corrosion resistance is poor. Addressing issues such as pinholes is key to being a protective coating in marine atmospheres.

The purpose of the present invention is to provide an ion-plated TiAlN coating for naval aeroengine compressor blades, which solves the problem of hindering the application of ion-plated TiN coatings without the need for equipment modification by using composition modulation and process parameter control. In order to solve the problems of pinholes and cavities in the anti-corrosion field, the hard coating was creatively applied to the protective coating of the compressor blades of naval aeroengines.

The ion plating TiAlN coating process method of the present invention is as follows:

Using IPB30/30T hollow cathode ion coating machine, according to the difference in melting point and vapor pressure of titanium and aluminum in the plating material and the difference in reactivity, the deposition parameters are controlled to form an Al-(Ti,Al)N-TiN interfaceless gradient coating , the plating material is a TiAl alloy containing 20% to 50% (atomic percentage) of Al, the temperature of the substrate during the deposition process is 400 to 480°C, the beam current of the electron gun is adjusted to 180 to 220A, the bias voltage of the substrate is -100 to -150V, and the vacuum Pressure < 0.01Pa, deposit the bottom layer of TiAl alloy on the surface of the workpiece, the coating time is 1-2min, introduce N ₂ , the vacuum degree is 0.15-0.4Pa, in the early stage of coating, the beam current of the electron gun is 280-320A, and the bias voltage is -20-20 -30V, the deposition time is 10~20min; the electron gun beam current is increased to 400~450A in the later stage of coating, the bias voltage is adjusted to -50~-60V, and the deposition is continued for 60~80min, and the coating thickness is 6~8μm. The layer is rich in Al, and the outer layer is hard (Ti, Al)N and TiN with B1NaCl structure. Due to the addition of an appropriate amount of Al, the bonding of the film/substrate interface is effectively enhanced, the number and diameter of pinholes in TiN are reduced, and the thin film Defects such as internal voids improve the compactness of the film. The film deposited by this method has high film-base bonding force, high hardness and wear resistance, and good corrosion resistance and particle erosion resistance. It is suitable as a protective coating for knives, molds and compressor blades of naval aeroengines.

The advantages of the present invention are: the use of component modulation and process parameter control solves the problems of pinholes and cavities that hinder the application of ion-plated TiN coatings in the anti-corrosion field without the need for equipment modification. At 600 ° C, NaCl, Corroded under the combined action of water vapor and air for 10 hours, the base compressor blade material (1Cr11Ni2W2MoV stainless steel) oxidized and increased by 4mg/cm ² , and the surface of the sample deposited with the TiAlN composite coating was smooth without obvious corrosion.

The present invention is described in detail below by way of examples.

Example

Aeroengine compressor blades, after surface grinding, decontamination, acetone ultrasonic cleaning and alcohol rinsing, are loaded into the deposition chamber. During the coating process, the plated parts revolve and rotate in the vacuum chamber. The plated material in the crucible is Al 30% (atomic percentage ) TiAl alloy, the workpiece temperature during the deposition process is 450 °C. Before introducing N ₂ , the bottom layer of TiAl alloy was deposited on the surface of the workpiece, the electron gun beam current was 200A, the substrate bias was -100V, the vacuum degree was <0.01Pa, and the coating time was 1min. Introduce N ₂ , the vacuum degree is 0.2Pa, in the early stage of coating, the beam current of the electron gun is 300A, the bias voltage is -20V, and the deposition time is 15min; the beam current of the electron gun is increased to 400A, the bias voltage is adjusted to -50V, and the deposition is continued for 80min in the later stage of coating . The thickness of the coating is 6-8 μm.

Claims (1)

1. ion-plating TiAlN coating that is used for naval aviation engine compressor blade is characterized in that the ion-plating TiAlN coating processing method is as follows:

Utilize IPB30/30T type hallow cathode deposition, HCD film machine, difference according to the different and reactive behavior of titanium, aluminium fusing point and vapour pressure in the plating material, the control deposition parameter, form Al-(Ti, Al) N-TiN does not have the interface gradient cladding, the plating material is for containing the TiAl alloy of Al 20%～50% (atomic percent), substrate temperature is 400～480 ℃ in the deposition process, adjust the electron beam gun line at 180～220A, substrate bias is-100～-150V, vacuum tightness＜0.01Pa is in workpiece surface depositing Ti Al alloy underlayer, the plated film time is 1-2min, introduces N ₂, vacuum tightness is 0.15～0.4Pa, and in plated film early stage, the electron beam gun line is 280～320A, and bias voltage is-20～-30V, depositing time is 10～20min; Plated film later stage electron beam gun line is increased to 400～450A, bias adjustment to-50～-60V, continue deposition 60～80min, coat-thickness is 6～8 μ m, the rich Al of this coating internal layer, skin is the hard (Ti of B1NaCl structure, Al) N and TiN, because the adding of an amount of Al has effectively strengthened the combination at film/basic interface, reduced the quantity and the diameter of pin hole among the TiN, the defectives such as cavity of film inside have been eliminated, improved the compactness of film, in this way sedimentary film has higher film-substrate cohesion, high hardness and wear resistance and good corrosion resistance and anti-particle erosion ability are suitable for as cutter, the protective coating of mould and naval aviation engine compressor blade.