Abstract: A method for anodizing aluminum, wherein an object (29) made of aluminum or an aluminum alloy is anodized in an electrolytic solution (25), and thereby an anodized aluminum film is formed on a surface of the object (29), is provided. The electrolytic solution (25) is comprised of at least one acid selected from organic acids having two or more carboxylic groups, moves at an average speed of 15 cm/sec or less along at least an outer surface of the object (29). The anodization is performed under conditions that a temperature of the outer surface of the object (29) is 80° C. or less, and current density is in a range from 10 to 170 A/dm2.

Abstract: A method for anodizing aluminum, wherein an object (29) made of aluminum or an aluminum alloy is anodized in an electrolytic solution (25), and thereby an anodized aluminum film is formed on a surface of the object (29), is provided. The electrolytic solution (25) is comprised of at least one acid selected from organic acids having two or more carboxylic groups, moves at an average speed of 15 cm/sec or less along at least an outer surface of the object (29). The anodization is performed under conditions that a temperature of the outer surface of the object (29) is 80° C. or less, and current density is in a range from 10 to 170 A/dm2.

Abstract: An aluminum brazing method includes the steps of preheating aluminum members in the form of workpieces coated with flux and brazing material in antioxidizing atmosphere gas up to a temperature around the flux activating temperature, and then heating the aluminum members from the temperature around the flux activating temperature to the brazing temperature mainly by forced convection of the anti-oxidizing atmosphere gas. An aluminum brazing furnace includes radiation intercepting members which are provided in the brazing chamber and which intercept the heat radiation to the work-pieces.