Processing of new material aero engines and their key components

Xi'an Aviation Power Control Company Zhao Xinglong

Aeroengine components are operated under the harsh environment of high temperature, high pressure and high speed. With the continuous updating and upgrading of aero-engine technology, more and more composite materials are applied to new engines, and a large number of aerospace engine components are adopted. High-strength high-temperature resistant alloys, powdered alloy steels, single crystal alloys, and lightweight high-strength composite materials add difficulty to the cutting process and put forward higher requirements for processing technology.

1. Processing of nickel-based superalloy parts

Nickel-based superalloys are widely used in the aerospace industry. They have a series of advantages such as oxidation resistance, high temperature deformation resistance and good welding performance. They are suitable for manufacturing high temperature bearing parts and hot end parts of aerospace engines that work for a long time below 650 °C, but Due to the problems of many hard spots, extremely poor thermal conductivity, and large work hardening tendency, it often restricts on-site processing. Domestic and foreign scholars have carried out many researches on the cutting of superalloys. However, there are few researches on the processing parameters selection, tool selection and tool wear of various coated tools in the processing of nickel-based superalloys, which makes the on-site processing very difficult. The parts are shown in Figure 1. The material is GH2132, the parts are f10mm×2 000mm, the hardness is 320HBS; the batch is 500 pieces/month; the surface roughness value Ra=1.6μm is required after the parts are processed, and the product aspect ratio is 18, which is typical. Slim shaft parts.

Figure 1 Slim shaft parts

In the absence of a central hole, the conventional CNC lathe obviously can not meet the processing needs, and finally chooses the CNC vertical slitting automatic lathe CKN1120IV produced by Sichuan Pushinjiang Machine Tool Co., Ltd., in view of the processing characteristics of nickel-base superalloy and the special processing of processing equipment. In the way, through the cutting test results and analysis, the following conclusions are obtained: 1 The hard coated blade MT09T304-PM5-WSM30 is suitable for the processing of nickel-based superalloy. 2 processing nickel-base superalloy GH2132 blade, the main declination is generally selected 40 ° ~ 50 °, the secondary declination is generally selected 0.5 ° ~ 3 °, the blade inclination is generally selected -10 ° ~ -20 °, not easy to appear built-up edge Can guarantee the surface quality of the parts. 3 The cutting speed is preferably 95 to 120 m/min, and the feed amount is preferably 0.1 to 0.15 mm/r, and the surface roughness value Ra = 1.6 μm or more can be secured.

2. Processing of powder superalloy parts

The oil pump gear is one of the important hot end parts of the engine. Its working conditions are extremely demanding. In order to ensure the reliability and stability of the aero engine, for the materials of this part, the developed countries in Europe and the United States use powdered high-temperature alloy steel, which is evenly organized. The grain size is small, there is no obvious segregation, the degree of alloying is high, and the fatigue resistance is good. It is the material of choice for high-pushing engine gears, turbine disks and other components. When the high-vanadium powder metallurgy alloy steel of AHP-10V is ground, the roughness of the parts and the cracks generated by the grinding end face have always been one of the problems that plague the on-site processing. The parts are shown in Figure 2. The material AHP-10V, the surface hardness of the parts is ≥65HRC, and the center hardness is 30~45HRC. After the grinding process is completed, the roughness value of all external surfaces is guaranteed to be Ra=0.1μm, which meets the requirements of the drawings.

Figure 2 Parts to be processed

It is composed of 3 levels. The upper level and the lower level are Woven Geotextile and non woven textile.  The middle level is bentonite grains,  which are carefully selected from Liu Fangzi crude and filled in between the two levels after special processing.