Inner bore plasma spraying method

Abstract

An inner bore plasma spraying method comprises the following steps: first, adjusting the spraying position between a plasma cylindrical spray gun and a workpiece inner bore; then sending powder by a radial upward powder sending manner from the lower part of the pray gun; finally, according to the different spraying powder adjusting the flow amount of a powder sending gas to enable the powder to be fully heated and melted in the flame and upward shift a right angle. The inner bore plasma spraying method uses the radial upward powder sending manner from the lower part of the pray gun for powder sending, and the flow amount of the powder sending gas can be adjusted according to the different spraying powder, so that the powder can be fully heated and melted in the flame and upward shifts a right angle, the formation of spraying dead angles on the upper edge of the inner bore can be avoided, the coating performance of a coating on the upper edge of the inner bore can be improved, the hollow and empty spray problems of the coating can be avoided, and the inner bore plasma spraying method has the advantages of simple operation and strong practicability, and is suitable for the atmospheric pressure plasma or low pressure (vacuum) plasma spraying.

Description

technical field [0001] The invention relates to the technical field of plasma spraying, in particular to a method for plasma spraying inner holes. Background technique [0002] Since the heat source temperature of plasma spraying can reach tens of thousands of degrees, the range of materials that can be sprayed is very wide, including metals, non-metals, ceramics, etc., which can be used as plasma spraying materials, and the range of substrates is also wide. Plasma sprayed coatings are of good quality. Plasma spraying is mostly used in the field of aerospace and aerospace, and occupies a large market share in the field of thermal spraying, preparing coatings with insulation, wear resistance and wear sealing. [0003] However, in these fields, it is often necessary to spray the inner hole of the part. For some parts with a relatively large length and diameter, a special inner hole spray gun is generally used for spraying, but because the inner hole spray gun is limited by po...

AI Technical Summary

Problems solved by technology

[0004] For spraying the inner hole, the size of the conventional plasma (outer circle) spray gun is large, and it is impossible to spray the plasma gun perpendicular to the spray surface of the workpiece. The angle can only be adjusted to the limit angle of 70-80° where the spray gun and the workpiece do not collide. Spraying, such as figure 1 shown

In this way, a spraying dead angle is formed on the upper edge of the inner hole, where the coating is easy to form voids and virtual spraying, and the coating quality cannot meet the requirements, such as figure 2 shown

Images