Research On Magnesium Alloys Metallic Particle/Polymeric Coating

Magnesium alloys, which are most potential engineering structure material, are used widely in national defending and domestic fields. The main reasons are advantages of magnesium alloys, shortage and hard to recycle of metallic structure material. However, easy to corrosion corruption, when they are exposed to atmospheric environment and environment containing Cl^-、NO₃^-、SO₄^2-, has been one of main barriers of applications and developments of magnesium alloys.Main works and subsequences in the investigation are as following:1. According to low corrosion property and high conditions of surface treatment of magnesium alloys, the method of surface pretreatment and polymeric coating are taken, so the novel way of polyurethane coating applied to magnesium alloy for corrosion protection is put forward, and the effect is markedly;2. Basing on cavities of epoxy/polyurethane coating hardly blocking water or ions from infiltration, polyurethane paint modified by epoxy resin E20 and nano～mirco filling material is used, so epoxy and filling material modifying epoxy/polyurethane paint is lodged, and the results indicate that the coating become denser and corrosion resistance is improved subsequently;3. Aiming at high percentage and environment pollution of traditional paints, the method of improving paint solid percentage is used, then high solid epoxy/polyurethane paint is advanced, and it suggests that solid percentage of paint can be adjusted to 75% when filling material is taken up 30% of volume constitute of polyurethane resin;4. According to hard to describe mechanical properties of epoxy/polyurethane coating quantitatively, scratch test, pencil hardness test, wear resistance test, tensile test and martens hardness measurement are used by contrast, then quantitative relations of mechanical properties of epoxy/polyurethane coating and components of the coating are lodged, and the results suggested that characteristics of epoxy/polyurethane coating is similar to that of plastic material and its hardness and elastic module are enhanced markedly but adhesive force decreased slightly by filling material;5. Aiming at hard to show anti-corrosion and anti-penetration of epoxy/polyutethane coating quantitatively, immersion test, salt spray test, electrochemical tests and surface corrosive morphology of the coating test are used, then quantitative relations between coating impedance and anti-corrosion and anti-penetration properties of the coating are brought forward, and the results show that its anti-corrosion and anti-penetration properties is down with coating resistance decreasing with time;Finally, we analyzed problems and put forward prospective based on the present work.