Magnesium alloy raw material or magnesium alloy product and its conductive anti-corrosion coating method

Abstract

The invention provides a magnesium alloy raw material or product and a preparation method for a conductive anticorrosive coating thereof. The magnesium alloy raw material or product comprises a magnesium alloy substrate and the conductive anticorrosive coating bonded with the surface of the magnesium alloy substrate, wherein the conductive anticorrosive coating is composed of an aluminum layer or aluminum alloy layer and an iron-based amorphous alloy layer which are laminated, and the aluminum layer or aluminum alloy layer is laminated with the magnesium alloy substrate. The preparation method for the conductive anticorrosive coating comprises the following steps: preparing the aluminum layer or aluminum alloy layer on the surface of the magnesium alloy substrate and preparing the iron-based amorphous alloy layer on the surface of the aluminum layer or aluminum alloy layer. The magnesium alloy raw material or product provided by the invention has excellent anticorrosion performance and conductive performance and realizes the characteristic of anticorrosion on the basis that original conductive performance of the magnesium alloy substrate is not sacrificed, and the aluminum layer or aluminum alloy layer is used as a transition layer to allow the magnesium alloy substrate to be effectively bonded with the iron-based amorphous alloy layer.

Description

technical field [0001] The invention belongs to the technical field of magnesium alloy anticorrosion, and in particular relates to a method for a magnesium alloy raw material or a magnesium alloy product and a conductive anticorrosion coating thereof. Background technique [0002] Since magnesium alloy is the lightest metal structure material available, its specific gravity is only about two-thirds of that of aluminum, so it will have a comparative advantage in the future material competition, especially in some components that need to reduce weight. It has a better application prospect. However, due to the low electrode potential of magnesium at -2.36ev, this characteristic makes magnesium and its alloys prone to corrosion. [0003] At present, there are some methods to solve the corrosion of magnesium and its alloys. One of the methods is to use organic paint to treat magnesium and its alloys to form an insulating organic anti-corrosion coating on the surface of magnesiu...

AI Technical Summary

Problems solved by technology

However, this type of anti-corrosion method has the following disadvantages: although organic paint can effectively prevent corrosion, its disadvantage is that it does not conduct electricity. Even if some organic paints are added with conductive inorganic substances, their conductivity is still relatively poor compared with pure metals.

This type of anti-corrosion method has the following disadvantages: although the aluminum coating can meet the function of conductive anti-corrosion to a certain extent, its anti-corrosion performance still has a certain gap compared with the amorphous alloy coating, and the hard bottom of the aluminum coating is relatively low. Not resistant to scratches, therefore, the anti-corrosion effect is still not ideal for some occasions that are prone to scratches

This type of anti-corrosion method has the following disadvantages: the conductive powder coating forms an inorganic polycrystalline alloy coating, because there are grain boundaries in the polycrystalline, compared with the amorphous without grain boundaries, its corrosion resistance will be worse, and there is more aluminum and zinc. The hardness of crystal alloy coating is low

This type of anti-corrosion method has the following disadvantages: directly depositing an amorphous alloy coating on magnesium and its alloy substrates, the electrode potentials of magnesium and iron differ greatly, and galvanic corrosion is prone to occur over time; and the difference in thermal expansion coefficient between the two is also relatively large. Large, less prone to good binding

Moreover, the iron-based amorphous alloy coating anti-corrosion method is currently mainly used in the field of steel anti-corrosion and wear resistance, and the application in magnesium alloys is immature.

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