Anti-melting aluminum-silicon alloy corrosion gradient protective coating for solar thermal power generation, and preparation thereof

Abstract

The invention relates to an anti-melting aluminum-silicon alloy corrosion gradient protective coating for solar thermal power generation, and a preparation method thereof, in particular to an MoB / CoCr gradient protective coating for the inner wall of an aluminum-silicon alloy energy-storage material container for solar thermal power generation, and a preparation method thereof. The MoB / CoCr gradient protective coating is composed of a MoB / CoCr surface protective coating with the thickness of 130mu m and the heat expansion coefficient of 9.2*10<-6> / K and a Co-based alloy buffering transition coating with the thickness of 60mu m and the heat expansion coefficient of 12.5*10<-6> / K. The MoB / CoCr gradient protective coating is spray-painted on a 310S substrate through low-pressure plasma spray painting. Shown by implementation on specimens, the MoB / CoCr gradient protective coating is well matched with the 310S substrate, so that the stress cracking and peeling resisting capabilities of the coating are improved, and the number of thermal shock resisting times reaches 70; the MoB / CoCr gradient protective coating has low porosity, the MoB / CoCr surface protective coating has a porosity of 1.13%, and the buffering transition coating has a porosity of 0.84%; and both the MoB / CoCr surface protective coating and the MoB / CoCr coating powder material contain only two phases of CoMo2B2 and CoMoB.

Description

Technical field [0001] The invention relates to a gradient protective coating against molten aluminum-silicon alloy corrosion for solar thermal power generation and a preparation method thereof, in particular to a gradient protective coating of MoB / CoCr and a preparation method thereof, used for storing aluminum-silicon alloy storage in solar thermal power generation Protective coating on the inner wall of the material container. Background technique [0002] Our country has abundant solar energy resources, so we don't wait to catch up with the world's advanced level in the field of solar thermal power generation. The country has now included the construction of solar thermal power stations in the "Eleventh Five-Year Plan", but the technology and basic research are relatively weak in the heat storage link. In order to obtain better heat storage effects and improve the power generation efficiency of the entire system, An energy storage material with high working temperature, low ...

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Problems solved by technology

However, due to the continuous thermal shock of the aluminum-silicon alloy, cracks will appear on the surface of these coatings, and even the coating will be separated from the substrate, so that molten aluminum-silicon can penetrate into the substrate and react.

The main reason for this phenomenon is that the matching between the coating material and the substrate is poor, especially the difference between the thermal expansion coefficient is large, the coating is very prone to stress cracking or peeling, and it is difficult to meet the long life of the substrate. The application requirements, and the porosity of the coating prepared by supersonic flame spraying is relatively high. During the spraying process, the coating material will react with the air medium, thereby reducing the coating's ability to resist corrosion of molten aluminum-silicon alloys.

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