What Is The Cause Of Black Spots Produced By Anodized Film Of Aluminum Parts
Nov 25, 2022
What is the cause of black spots produced by anodized film of aluminum parts
Reason: Anodic oxidation solution used for too long, excessive accumulation of heavy metal ions in the solution.
Treatment method:
① With aluminum as anode, lead plate as cathode, small current electrolysis treatment, after each treatment of a certain amount of time will take out the lead plate to wash, and then continue to deal with, after a certain amount of time to deal with the situation will be greatly improved.
② The black spots on the surface of the anodized parts can be rinsed away in 1:1 nitric acid.
Sulfuric acid (chemical form: H₂SO₄), the most important oxygen-containing acid of sulfur. Anhydrous sulfuric acid is a colorless oily liquid, crystallized at 10.36℃, and its various aqueous solutions of different concentrations are usually used by tower method and contact method. The former is coarse dilute sulfuric acid, the mass fraction is generally about 75%; The latter can obtain a mass fraction of 98.3% pure concentrated sulfuric acid, boiling point 338℃, the relative density of 1.84.
