Process for the preparation of aluminum alloys to the aluminum cold conformacao

摘要

1501842 Preparing Al surfaces for coldforming PYRENE CHEMICAL SERVICES Ltd 11 Feb 1976 [17 Feb 1975] 05268/76 Heading C7U Al or Al alloy workpieces are treated by, (1) coating the surfaces with an aqueous solution containing an alkaline earth metal salt at a pH 8, preferably 10-13, (2) rinsing with water, (3) applying a lubricant to the workpiece, and (4) cold forming. The solution preferably contains an alkaline earth metal hydroxide and/or oxide in addition to the salt, which may be a bromide, nitrate, chloride, borate, acetate or mixtures of these, preferably of Ca. In Examples, Al-Mg alloys are treated with a solution of (a) 78 wt. per cent CaCl 2 , 22 wt. per cent Ca(OH) 2 at 70‹C, or (b) 73 wt. per cent Ca(NO 3 ) 2 , 27 wt. per cent Ca(OH) 2 at 70‹C. In the latter case, the solution may be replenished by adding a mixture of 67 wt. per cent Ca(NO 3 ) 2 33 wt. per cent Ca(OH) 2 . The lubricant is preferably an alkali metal or alkaline earth metal soap, e.g. a stearate.