[China Aluminum Industry Network] There are two main reasons for the formation of oxide films in the holes of aluminum profiles and around them: Non-Wonven Polishing Wheel,Non Woven Steel Polishing Wheel,Buffing Wheel For Drill,Aluminum Polishing Kit Jiangmen Gude Polishing Equipment Co., Ltd , https://www.kokipolishing.com
(1) The aluminum parts are washed thoroughly after caustic washing. Alkali which enters the pores during caustic washing fails to be washed cleanly. After the oxidation treatment, the caustic soda flows out of the cylinder, causing the oxide film around the pores to be corroded.
(2) There are liveliness around the hole of the aluminum workpiece. Aluminium tapping screw hole is very astringent, the operator often lacquer to lubricate, if the lack of emulsifier alkali in the alkaline wash, it is difficult to dilute.
Solution:
(1) Wash it with gasoline before caustic washing, emulsifier should be added in caustic solution;
(2) The workpiece should be washed after caustic washing.
Analysis of the Causes of Formation of Oxide Films in Holes and Oxides of Aluminum Oxidation Parts