| 摘要 |
PURPOSE:To improve corrosion resistance of Mg or Mg alloy parts, by forming a coating film of chromate contg. fluoride on the surface of the parts, then by vacuum-evaporating a coating film of silane coupling material and a high molecular film of paraxylylene dimer etc. on the chromate film. CONSTITUTION:Parts made of Mg or Mg alloy is treated by immersing them in an aqueous soln. consisting of 150-300g/l dichromate such as K2Cr2O7, Na2Cr2O7 etc., 2-100g/l fluoride such as MgF2, KF, NH4HF2 etc., 5-200ml/l mineral acid such as nitric acid for 1-40min to form chromate coating contg. fluoride on the surface of the parts. Then the parts are treated with a soln. of vinyl trichlorosilane in metanol to form a coating film of silane coupling agent. In addition, the parts are heated in the dimer atmosphere of para-xylylene or its substitution product to form a high molecular coating film contg. the dimer as monomer redical 3-7mum in thickness. Hereby the anticorrosion function of Mg or Mg alloy is remarkably improved. |
