Magnesium alloy surface treatment process

Abstract

The invention relates to a magnesium alloy surface treatment process which comprises the following steps: (1) soaking and coating phosphate film-forming solution on the surface of a magnesium alloy matrix, washing by water and drying to generate a layer of transition films; and (2) externally coating non-chromate Dacromet coating to obtain a protective coating, wherein the phosphate film-forming solution is sn aqueous solution comprising the following components in concentration: 20-45 g / L of phosphoric acid; 2-4.5 g / L of zinc oxide, 1-4.5 g / L of sodium fluoride, 0.5-2 g / L of ammonium fluoride, 0.5-3 g / L of crystallization controlling agent, 0.5-2 g / L of reaction promoting agent and 0.5-2 g / L of anion surface active agent; the crystallization controlling agent is selected from molybdate or rare-earth salt, and the reaction promoting agent is selected from nitrate or chlorate. The corrosion resistance of the processed magnesium alloy surface is effectively improved.

Description

(1) Technical field [0001] The invention relates to a magnesium alloy surface treatment process. (2) Background technology [0002] In the 21st century, resources and the environment have become the primary issues of human sustainable development. With the sharp increase in the consumption of metal materials, the rapid development of science and technology, the emergence and widespread use of large-scale production processes, the resources of the earth's surface are becoming increasingly depleted. Some metal materials - iron, aluminum, copper, lead, zinc, etc., will not last for more than a hundred years, or even decades. This will put forward higher requirements for the traditional manufacturing industry, which is under huge environmental pressure at the cost of resource consumption. Therefore, reducing environmental pollution and saving the limited resources of the earth, and then realizing the sustainable development of human beings, is a very important and urgent issue...

AI Technical Summary

Problems solved by technology

[0003] At present, in the research and application development of magnesium alloy materials, in view of the extremely active characteristics of magnesium element, the key technical problems that need to be solved urgently are: it is very easy to oxidize and burn during smelting and processing, and the production is very difficult; the corrosion resistance is poor; the existing products The high-temperature strength and creep properties are low, and the application in high-temperature (150-350°C) occasions is limited; the mechanical properties at room temperature, especially the strength and plastic toughness need to be improved

Among them, the coating technology of magnesium alloy, in the humid atmosphere, the corrosive medium easily penetrates the micropores of the coating, which reduces the bonding force and corrosion resistance of the coating layer.

Micro-arc oxidation treatment technology and plasma spraying technology are not only expensive, but also have problems such as difficult control of process quality and unsatisfactory adhesion between coating and it.

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