Method for repairing aircraft fuel system aluminum silicon alloy shell casting defects

Abstract

The invention relates to the technical field of aircraft fuel system mechanical part accessory repairing, in particular to a method for repairing aircraft fuel system aluminum silicon alloy shell casting defects. The method includes the following steps of S1, decomposition cleaning; S2, defect positioning and removal; S3, dye penetration; S4, cleaning; S5, protection; S6, surface pretreatment; S7,preheating before spraying; S8, cold spraying; S9, coating processing; S10, stress relief treatment; S11, dye penetrant inspection; and S12, anti-corrosion treatment. According to the method for repairing the aircraft fuel system aluminum silicon alloy shell casting defects, the problems of a heat crack of a shell and base material annealing softening caused by large heat input of a traditional surfacing process are effectively avoided, the repairing problem of the aircraft fuel system aluminum silicon alloy shell casting defects is solved, at the same time, casting defect repairing of the shell can be realized under the operation temperature of less than 120 DEG C, the problem of scrapping of a whole part of accessories due to shell damage or secondary damage caused by repairing is avoided, and economic benefits are significant.

Description

technical field [0001] The invention relates to the technical field of repairing accessories of the mechanical part of an aircraft fuel system, in particular to a method for repairing casting defects of an aluminum-silicon alloy shell of an aircraft fuel system. Background technique [0002] In order to achieve weight reduction, the aircraft uses a large number of light alloy materials such as aluminum alloys. Among them, aluminum-silicon alloys are widely used in the manufacture of various parts and accessories in the aircraft fuel system due to their light weight, good strength, and excellent casting performance. Due to the characteristics of the casting process itself, defects such as porosity, blisters, shrinkage cavities, and pores are prone to exist inside the castings, which has always been a problem in the industry. Under the multiple effects of the working load and the use environment, such defects are prone to expand and cause cracks, leakage, holes and other failu...

AI Technical Summary

Problems solved by technology

Under the multiple effects of the working load and the use environment, such defects are prone to expand and cause cracks, leakage, holes and other failures in the shell, resulting in failure of parts and accessories

Due to the poor interchangeability of the shell parts and the high processing difficulty, if it cannot be repaired, the only solution is to replace the entire parts and accessories, which is costly and subject to external constraints

[0003] At present, the main repair method for casting defects is surfacing welding, but the welding process itself has a large heat input. If the process is not properly controlled, the damaged repair area of ​​the part is large, or the structure itself is thin, it is easy to appear near the heat-affected zone due to thermal stress. cracks, and at the same time cause annealing softening of surrounding parts, affecting the performance of the entire product

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