The invention relates to a continuous coil surface treatment process suitable for both a coil of a 5XXX aluminum alloy sheet and of a 6XXX aluminum alloy sheet. The process comprises the successive steps of etching the surface with a fluorine-free acidic solution; rinsing with deionized water; applying a conversion solution comprising titanium and zirconium, and drying. The invention surface treatment method is environmentally friendly and enables the production of the treated surfaces in an efficient and reliable manner for both 5XXX and 6XXX alloys. It is particularly adapted for the production of aluminum alloy sheets for the automotive industry.

The invention relates to a continuous coil surface treatment process suitable for both a coil of a 5XXX aluminum alloy sheet and of a 6XXX aluminum alloy sheet. The process comprises the successive steps of etching the surface with a fluorine-free acidic solution; rinsing with deionized water; applying a conversion solution comprising titanium and zirconium, and drying. The invention surface treatment method is environmentally friendly and enables the production of the treated surfaces in an efficient and reliable manner for both 5XXX and 6XXX alloys. It is particularly adapted for the production of aluminum alloy sheets for the automotive industry.

An aluminum-based metal-resin composite structure (106) includes an aluminum-based metal member (103) in which a dendritic layer (103-2) is formed on at least a part of a surface, and a resin member (105) bonded to the aluminum-based metal member (103) via the dendritic layer (103-2) and formed of a thermoplastic resin composition, in which, when analysis is conducted with a Fourier transform infrared spectrophotometer (FTIR) on a surface (104) of a bonding portion with at least the resin member (105) in the aluminum-based metal member (103) and an absorbance of an absorption peak observed at 3400 cm.sup.−1 is defined as A.sub.1 and an absorbance at 3400 cm.sup.−1 of a straight line connecting an absorbance at 3800 cm.sup.−1 and an absorbance at 2500 cm.sup.−1 is defined as A.sub.0, an absorbance difference (A.sub.1−A.sub.0) is in a range of 0.03 or less.

An aluminum-based metal-resin composite structure (106) includes an aluminum-based metal member (103) in which a dendritic layer (103-2) is formed on at least a part of a surface, and a resin member (105) bonded to the aluminum-based metal member (103) via the dendritic layer (103-2) and formed of a thermoplastic resin composition, in which, when analysis is conducted with a Fourier transform infrared spectrophotometer (FTIR) on a surface (104) of a bonding portion with at least the resin member (105) in the aluminum-based metal member (103) and an absorbance of an absorption peak observed at 3400 cm.sup.−1 is defined as A.sub.1 and an absorbance at 3400 cm.sup.−1 of a straight line connecting an absorbance at 3800 cm.sup.−1 and an absorbance at 2500 cm.sup.−1 is defined as A.sub.0, an absorbance difference (A.sub.1−A.sub.0) is in a range of 0.03 or less.

An aluminum alloy brazing sheet used for brazing in an inert gas atmosphere without using a flux includes an intermediate material and a brazing material cladded onto at least one side surface of a core material in this order from the core material side. An oxide is formed on a surface of the aluminum alloy brazing sheet by brazing heating, the oxide including any one or two or more of Mg, Li, and Ca and having a volume change ratio of 0.990 or less to a surface oxide film formed before brazing heating, and an atomic molar ratio of Mg, Li, and Ca to Al in the oxide formed on the surface of the aluminum alloy brazing sheet before brazing heating is 0.5 or less. The present invention provides an aluminum alloy brazing sheet having excellent brazability in brazing in an inert gas atmosphere without using a flux, and a method for manufacturing the same.

An aluminum alloy brazing sheet used for brazing in an inert gas atmosphere without using a flux includes an intermediate material and a brazing material cladded onto at least one side surface of a core material in this order from the core material side. An oxide is formed on a surface of the aluminum alloy brazing sheet by brazing heating, the oxide including any one or two or more of Mg, Li, and Ca and having a volume change ratio of 0.990 or less to a surface oxide film formed before brazing heating, and an atomic molar ratio of Mg, Li, and Ca to Al in the oxide formed on the surface of the aluminum alloy brazing sheet before brazing heating is 0.5 or less. The present invention provides an aluminum alloy brazing sheet having excellent brazability in brazing in an inert gas atmosphere without using a flux, and a method for manufacturing the same.

A metal-resin composite structure (106) is formed by bonding a metal member (103) and a resin member (105) formed of a resin composition. A surface roughness measured regarding six linear portions in total including three arbitrary linear portions parallel with each other and another three arbitrary linear portions perpendicular to the former three linear portions on a surface (110) of the metal member (103), based on JIS B0601 (corresponding international standard: ISO4287) satisfies both Requirements (1) and (2). (1) An average value of ten point average roughnesses (Rz) at an evaluated length of 4 mm is smaller than 20 μm. (2) An average value of mean width of the profile elements (RSm) at an evaluated length of 4 mm is equal to or greater than 20 μm and smaller than 77 μm.

An etchant composition for wet etching a titanium-containing film. The etchant composition includes hydrofluoric acid as a primary oxidant, a co-oxidant that forms a dense oxide film on a surface of a titanium film during an etching process, an alkali metal salt that inhibits aggregation and adsorption of titanium ions during the etching process, and a solvent.

A thickness-detecting bond primer is disclosed. In various embodiments, the thickness-detecting bond primer includes a solvent configured for application to a metallic surface; and a dye dispersed within the solvent, the dye having a concentration within a range of about 0.001 weight percent to about 5.0 weight percent of the thickness-detecting bond primer.

A thickness-detecting bond primer is disclosed. In various embodiments, the thickness-detecting bond primer includes a solvent configured for application to a metallic surface; and a dye dispersed within the solvent, the dye having a concentration within a range of about 0.001 weight percent to about 5.0 weight percent of the thickness-detecting bond primer.