| abstract |
Provided is a chromium-free treatment solution capable of imparting low electrical resistance and high corrosion resistance capable of realizing electromagnetic wave shielding properties to the surface of a metal member such as a magnesium member and an aluminum member. One or more selected from the group consisting of vanadium ion and / or vanadyl ion, organic acid ion, nitrate ion, sulfate ion, phosphorus oxyacid ion, boron oxyacid ion, and chlorine oxyacid ion An acidic metal surface treatment liquid containing no chromium. [Selection figure] None |