Method for spraying inner wall with novel plasma cored wire

Abstract

The invention discloses a method for spraying the inner aperture wall with a novel plasma cored wire. The method comprises the following steps: 1, preprocessing the surface of a workpiece; 2, selecting an iron-based cored wire containing an antifriction wear-resistant powder core added with molybdenum (Mo), chromium (Cr), nickel (Ni), boron (B), silicon (Si), and iron (Fe) components and a stainless steel shell, and spraying the iron-based cored wire on the small inner aperture surface of the workpiece through a plasma transferred wire arc (PTWA) spraying technology to obtain a wear resistantcoating; and 3, carrying out honing processing on the prepared wear resistant coating. The wear resistant coating prepared through the method of the invention has the advantages of high strength of the combination with a matrix, difficult shedding, hardness higher than the hardness of traditional cast iron liners, substantially improved wear resistance, realization of the oil storage function of 1-5% of apertures formed through the coating technology, lubrication promotion to reduce antifriction, and the like, so problems of weight and dimension increase of the cast iron liner of an aluminum alloy engine cylinder and problems of oil consumption and discharge increase caused by the thermal expansion of the inner wall of the cylinder are solved.

Description

Technical field [0001] The invention relates to the technical field of wear-resistant antifriction coatings, and not only relates to a spraying process for preparing a wear-resistant coating on the inner wall of an automobile engine cylinder, but also relates to a new type of plasma powder core wire inner wall spraying method. Background technique [0002] At present, under the development trend of energy saving and emission reduction, reducing the quality of the engine is one of the important ways to reduce the weight of automobiles. Automobile engines are gradually replaced by traditional cast iron by aluminum alloy materials. However, the strength and strength of aluminum alloy in the existing technical solutions The hardness is significantly lower than that of cast iron. Cast iron bushings should be inserted on the inner wall of the cylinder to increase the strength. This will increase the overall weight and size of the engine, which is not conducive to energy saving. In addit...

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Problems solved by technology

[0002] At present, under the development trend of energy saving and emission reduction, reducing the mass of the engine is one of the important ways to reduce the weight of the car. The traditional cast iron is gradually replaced by the aluminum alloy material for the car engine, but the strength and The hardness is obviously lower than that of cast iron, so it is necessary to inlay cast iron bushings on the inner wall of the cylinder to increase the strength, which will increase the overall weight and size of the engine, which is not conducive to energy saving. In addition, the difference in thermal expansion coefficient between cast iron and aluminum alloy will also cause heat deformation of the bushings Therefore, it is separated from the inner wall of the aluminum alloy cylinder, which increases fuel consumption and excrement, which does not meet the requirements of energy saving and emission reduction

[0003] Another method in the prior art is to use stainless steel wire or low-carbon steel wire to prepare stainless steel coating and low-alloy carbon steel coating on the inner wall of the cylinder. Although the overall weight is much lower than that of the inlaid cast iron bushing, the low-alloy carbon steel coating Although the wear resistance is good, it is not resistant to gas corrosion, and although the stainless steel coating has good gas corrosion resistance, its wear resistance is insufficient

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