Cold spraying remanufacturing process for surface of outer cylinder of landing gear

Abstract

The invention relates to a cold spraying remanufacturing process for the surface of an outer cylinder of a landing gear. The process comprises the following specific steps that the surface of the outer cylinder of the landing gear to be sprayed is cleaned with acetone, various oil stains and impurities are removed, and a spraying area and a non-spraying area are divided; sand blasting treatment iscarried out on the spraying area on the surface of the outer cylinder of the landing gear to be sprayed, and after sand blasting is completed, sand grains and ash are removed; and within two hours after sand blasting treatment, and low-pressure cold spraying equipment is adopted to prepare a layer of pure zinc coating on the spraying area of the surface of the outer cylinder of the landing gear to be sprayed. The process has the following advantages that the oxidation, pores and inclusions of the coating are less, the thickness fluctuation is small, the density is higher, and the corrosion resistance is improved; the residual tensile stress of the coating is low, and the stripping resistance is high; the requirement on the surface state is low, and the process can be suitable for remanufacturing and the uneven surface and old coating surface of a repaired part; no open fire exists in the construction process, and the construction process is safer; and the heat input is relatively low,and the heat influence on the ultra-high-strength steel material matrix of the outer cylinder of the landing gear is smaller.

Description

Technical field [0001] The present invention relates to the field of surface treatment technology, in particular to a cylindrical outer surface of the cold spray undercarriage remanufacturing process. Background technique [0002] Landing gear is the key load-bearing structural components of the aircraft, to carry out a very important mission in the safety of the aircraft during takeoff and landing. Aircraft movements to resist, ultra-high load during cornering, landing gear used for producing ultra-high strength steel, while using a combination of a piston rod plus landing gear shock absorbing structure of the outer cylinder. Cracking of ultrahigh strength steel is often very sensitive to stress corrosion and corrosion fatigue. Thus, in manufacturing a landing gear components, some surfaces are required for coating protection, a metal such as zinc plating layer. [0003] Zinc metal as an important element, is widely used on the steel surface to improve the corrosion prevention s...

AI Technical Summary

Problems solved by technology

In the traditional process, the metal zinc layer sprayed on the outer cylinder of the landing gear adopts the thermal spray zinc process. Compared with the electro-galvanized layer, the thermal spray zinc process is relatively environmentally friendly, has low pollution, and has no risk of hydrogen embrittlement sensitivity, and can prepare thick coatings , so as to obtain better corrosion resistance, the traditional process CN201110067318.8 "A New Process for Thermal Spraying Zinc Corrosion of Steel Pipe Rods", but this process uses oxyacetylene flames, electric arcs, etc. to heat zinc wires, and in the remanufacturing process of the repair industry , there are problems such as large thermal impact on the ultra-high-strength steel landing gear substrate, large thermal stress, low performance of the coating, and high construction risk

Reference document 2CN101063204B "Manufacturing method of galvanized steel sheet" describes a method for preparing steel sheet by cold spraying of zinc layer, but this method cannot be applied to the field of remanufacturing of ultra-high-strength steel landing gear with complex shapes on aircraft , In addition, there is no clear inspection requirement for the coating effect in this method, and it is impossible to carry out effective effect inspection on the landing gear after spraying

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