Study On The Silanization Treatment On The Surface Of Magnesium Alloy

Magnesium and its alloys are lightest metal structural engineering materials and have a very broad application,such as transport,aviation,military areas and small to 3C products.High chemical activity and low corrosion resistance of magnesium alloy limits its large scale application in various fields, especially in the automotive and aerospace industry.Therefore,the development of effective magnesium and magnesium alloy corrosion protection system for its industrial application is extremely important.Phosphate conversion coating and chromate conversion coating technology are the best technologies in the international metal surface protection field nowadays.But the two technologies is not adapt the development of modern industry because of their toxicity and high energy consumption.Silane treatment technology as a new and energy saving technology grows up fast.After nearly twenty years research and development,the silanization treatment technology of metal surface has made many important achievements,part of the technology has been applied in the industry of automotive coating production line.At present,the formation mechanism and structural characterization of silane film on metal surfaces has a lot of research,but the research on hydrolysis and failure of silane agent and surface modified has some success,but it needs to be further explored.In this paper,on the basis of previous studies,many questions and status that currently exist in silanization treatment process of magnesium alloy surface have been studied.The hydrolysis conditions of Vinyltriacetoxysilane(VTAS) and double-triethoxysilane silylpropyl amine (BTSPA) applicable to magnesium alloys and optimization of film-formation process conditions have been determined.Finally silane hydrolysis conditions which is suitable for magnesium alloy is that the optimal hydrolysis conditions of BTSPA is content of silane,alcohol-water ratio,pH,temperature:3ml,20:80,6,35℃;The optimum hydrolysis conditions of the mixture of BTSPA and VTAS is content of silane,alcohol-water ratio,pH,temperature:8ml,80:15,4,25℃.Film forming conditions were that the dipping time is 60 seconds,the curing temperature is 100℃ and the curing time was 30 minutes.