| 摘要 |
PURPOSE:To enhance the nondirectional properties and whiteness of the surface of Al contg. prescribed amounts of Fe, Mn, Ti and Cr by treating the Al with a chlorine-free treating soln. contg. prescribed amounts of HF and HNO3 or orthophosphoric acid. CONSTITUTION:Al contg. 0.7-2wt% Fe or 0.5-2wt% Fe and 0.5-2wt% one or more among Mn, Ti and Cr is prepared. This Al is immersed in a chlorine-free treating soln. contg. 0.2-80wt% HF and 0.2-80wt% HNO3 or orthophosphoric acid. Thus, a nondirectional white surface with >=80 L-value and <=5 directional properties (DELTAL) is obtd. |
