SURFACE TREATING METHOD FOR ALUMINUM ALLOY EXTRUDED SHAPE MATERIAL

摘要

PROBLEM TO BE SOLVED: To obtain an aluminum alloy extruded shape material in which a feeling of roughness with large ruggedness has been imparted. ;SOLUTION: An Al-Mg-Si base aluminum alloy extruded shape material is subjected to extrusion working and is thereafter subjected to heat treatment of executing heating at 180 to 230°C for 1 to 4 hr, next, the aluminum alloy extruded shape material is immersed into a hydrochloric acid-containing aqueous solution to form fine ruggedness on the surface of the material, and moreover, the aluminum alloy extruded shape material is immersed into an alkaline aqueous solution to expand the ruggedness. As to the immersing treatment into a hydrochloric acid-containing aqueous solution, the aluminum alloy extruded shape material is immersed into a hydrochloric acid-containing aqueous solution having a concentration of 10 to 200 g/L and a bath temperature of 20 to 50°C for 1 to 20 min. As to the immersing treatment into an alkaline aqueous solution, the aluminum alloy extruded shape material is immersed into a sodium hydroxide aqueous solution having 7 concentration of 20 to 100 g/L, bath temperature of 30 to 70°C and pH of 13 or more for 3 to 20 min.;COPYRIGHT: (C)2001,JPO