Process for preparing compact thick protection layers on magnesium alloy surfaces

Abstract

A process for preparing compact thick protection layers on magnesium alloy surfaces, which includes steps of surface pretreatment, flame plating alloy powder, laser remelting and the like, is added with a surface pretreatment procedure of deoxidation galvanization, and reasonably determines key process parameters. The process is particularly characterized in that solution of the deoxidation galvanization is water solution prepared by hydrofluoric acid (50ml / L) and zinc sulfate heptahydrate (50g / L), time of the deoxidation galvanization procedure ranges from 15 seconds to 20 seconds, preheating temperatures of primary plating and secondary plating of the flame plating are respectively 60-120 DEG C and 150-200 DEG C, laser power of the laser remelting ranges from 1250 W to 1500 W, scanning speed thereof is 500mm / min, and light spot diameter thereof is 4mm. The thickness of a protection layer obtained by preparing flame plating aluminium-silicon alloy powder and laser remelting achieves over 1.5mm, the protection layer is compact in structure without shortages of pores and the like, rigidity of the protection layer ranges from 225HV to 270 HV( which is 4.5-4.9 times of that of a substrate, the thickness direction of the protection layer seldom changes, the component (by mass percentage) of the protection layer is 33.77-53.35Al-62.04-40.76Mg-4.19-5.89Si, and boundaries of the protection layers are in alloy combination.

Description

Preparation method of dense and thick protective layer on magnesium alloy surface technical field The invention relates to a surface treatment method of a magnesium alloy, in particular to a preparation method for forming a dense and thick protective layer on the surface of a magnesium alloy, in particular to a method for preparing a dense and thick protective layer on the surface of a magnesium alloy. Background technique As we all know, magnesium alloy has light weight, high specific strength, high specific stiffness, good shock absorption and vibration absorption performance, good electromagnetic shielding, excellent thermal conductivity, good machining performance, easy casting, good biocompatibility, and infinite reuse, etc. Excellent performance, has broad application prospects in aerospace, weaponry, vehicles (including automobiles, airplanes, motorcycles, bicycles, etc.), 3C, medical equipment and other fields, but its hardness is low, wear resistance and corrosion ...

AI Technical Summary

Problems solved by technology

The purpose of the present invention is to solve the problem that it is difficult to form a dense and thick protective layer on the surface of magnesium alloys, which affects its performance and use, and to invent a method that organically combines various existing surface treatment methods and can finally obtain a protective layer with a thickness of 1.5 mm. The preparation method of above dense protective layer

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