PROCESS FOR PRODUCING SURFACE CONDITIONED ALIUMINIUM CASTINGS

摘要

[PROBLEMS] TO PROVIDE A MEANS FOR AVOIDING DEFECTIVE TREATED SURFACE APPEARANCES OR DEFECTIVE FILM PERFORMANCES AFTER COATING IN TECHNIQUES FOR NONCHROMATE CONVERSION TREATMENT OF ALUMINUM CASTINGS EVEN WHEN A SURFACE CONDITIONING STEP WITH A STRONG ALKALI IS CARRIED OUT BEFORE THE CONVERSION TREATMENT. [MEANS FOR SOLVING PLOBLEMS] A PROCESS FOR PRODUCING SURFACE CONDITIONED ALUMINUM CASTINGS, COMPRISING A STEP OF APPLYING TO ALUMINUM CASTINGS AN ALKALINE SURFACE CONDITIONING LIQUID CONTAINING AT LEAST ONE ORGANIC BUILDER AND/OR ONE CHELATING AGENT, WHEREIN THE ALKALINE SURFACE CONDITIONING LIQUID USED IN THE STEP HAS A SURFACE CONDITIONING ACTIVITY (CD; MOL/L) IN THE RANGE OF 0.05 ? CD ? 2.3 AND A COEFFICIENT OF GLOSS (CE; G/MOL) IN THE RANGE OF 2.8 ? CE ? 90.