Electroplastic auxiliary cold spraying device and coating preparation method

Abstract

The invention discloses an electroplastic auxiliary cold spraying device and a coating preparation method. The electroplastic auxiliary cold spraying device and the coating preparation method are suitable for a hard base body where powder is difficult to deposit and conductive powder which is prone to crack after deposition, a pulse power supply introduces pulse current into the base body through a positive electrode and a negative electrode, and air flow in an air storage tank is output in two ways after passing through an air valve, one air flow flows into a gas heater to be heated, the other air flow carries spraying particles after passing through an output port of a powder feeder, the two air flows impact the base body after being accelerated by a Laval nozzle, and a sample table drives the base body to circularly move according to a set spraying track, and a coating is formed on the base body. According to the electroplastic auxiliary cold spraying device and the coating preparation method, the electrodes are placed at the two ends of the base body, the pulse current is introduced, and softening of a base body material is stimulated, so that mechanical combination between the coating and the base body is facilitated, and therefore the combination strength of the coating and the base body is improved; and after the bottom layer coating is combined with the base body, pulse current is introduced into the bottom layer coating, so that during subsequent particle impact, combination of the bottom layer coating and the base body is tamped, and the compact coating low in porosity is formed.

Description

technical field [0001] The invention relates to the technical field of cold spraying technology and electroplastic processing, in particular to optimize the cold spraying coating deposition device and coating preparation method under pulse current conditions, especially suitable for hard substrates that are difficult to deposit powder and cracks are easy to occur after deposition conductive powder. Background technique [0002] Cold spraying technology uses high-pressure gas to drive powder particles to form a supersonic two-phase flow after the convergence and divergence of the Laval nozzle. When the speed of the powder reaches or exceeds the critical speed, the sprayed powder is deposited on the surface of the substrate through large plastic deformation. Build up the coating gradually. Cold spray coatings can effectively prevent high temperature, oxidation and chemical corrosion, and are currently widely used in aerospace, automotive, energy, medical, marine and other fie...

AI Technical Summary

Problems solved by technology

However, the preparation of cold spray coatings also faces many problems: when the hardness of the matrix material is too large, it will limit the deposition particles embedded in the matrix, and the bonding strength is difficult to guarantee, which is not conducive to the growth of the coating, resulting in a low thickness of the coating; some particles The deposition needs to reach a high critical speed, and the performance parameters of the cold spray device are high; the combination between particles cannot produce a dense, small porosity coating, or even cracks, etc.

Electroplasticity is widely used in plastic forming processes such as wire drawing, rolling, deep drawing, and incremental forming, but it has no application in the field of cold spraying, which also has high requirements for plasticity.

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