ISO 8080-2021 pdf download.Aerospace一Anodic treatment of titanium and titanium alloys – Sulfuric acid process.
4.1.7 The following pickling solution contarning a mixture of nitric and hydrofiuorlc actds at the
following concentrations can be used as a reference:
— 280 a/i to 560 a/I of HNO1 (60 g/kg)
— lSg/1to25g/IoIHF(700gJkg).
Nitric and hydratluonc acids concentrations can be changed, or alternative chemical products can be used, when agreed between the OEM and the processor, provided that anodic layer meets all requIrements of this document.
4.2 PreparatIon br anodizing
4.2.1 Parts shall be thoroughly .ilkaline cleaned to ensure that all surfaces are free from contaminants such as grease, ad and mill markings
4.2.2 Chlorinated solvents and methyl akohol shall not be used (or degreasing.
4.2.3 Parts shall be firmly atuched to the racking device. Contact areas shall be kept as small as possIble and, when practicable, shall be on a surface not required to be coated. When parts arc to be coated on all surfaces, contacts áaII be lusattsI on areas Indicated on the drawrng
4.2.4 Parts shall be oriented eons to minimize gas entr.iprnent dunng processing.
4.2.5 After cleaning, parts shall be etched for a minimum duration to guarantee surface activation in an acid pickling solution (see 4.1.7) and then rinsed thoroughly in cold running water Heavily scaled parts which do not provide a clean, bright surface after the treatment outlined above may require tine alumina grltblasting or pretiratnient In an oxidizing alkaline solution prior to etching.
NOTE Surface activatIon is correct when the surface is visually clean and bright.
4.2.6 As an alternative, a mechanical activation can be used for surface preparation it agreed between the original equipment manufacturer (OEM) and the processor.
4.3 AnodizIng procedure
4.3.1 The parts shall then be Immersed In the anodizing solution. The parts shall be made the anode and iii, tank or auxiliary plates, the cathode, Current shall be applied to reach the desired coloration Recommended voltage cycle: from IS V to 20 V for a period of IS mm or until the desired coloration has been achieved. The recommended initial current density should be approximately 0.2 A/dm2, with a reduction to an approximate value 0(0.05 A/dmz over the greater part of the anodizing cycle.
4.3.2 During processing of Intricate parts, the wiuticas should be agitated In order to niinl,nkze entrapment of gas in pockets and blind holes. If necescar parts should be repositioned periodically to bring the electrolyte into contact with uncoated areas and to prevent attack at the liquid/gas interface in pockets and blind holes.
43.3 Alter completion of the anodizing cyde. parts shall be rinsed thoroughly in cold, running water. then flnaed In clean, hat water and dried.ISO 8080 pdf download.