Nonchromated Spray Paints on Plasma Polymer Surfaces

CHROMATED AND NONCHROMATED SPRAY PAINTS ON PLASMA POLYMER SURFACES 

The aluminum alloys that have been investigated in the previous sections, including [2B], [7B], and [2A], are materials used for aircraft skins. Aircraft skins are readily 

A PPG cathodic E-coat, designated E2, was used. The chromated spray primers employed were water-borne Deft 44-GN-36 (A) or 44-GN-72 (Al) (Deft Corporation, Irvine, CA) and solvent-borne Courtauld 519X303 (G) (Courtauld Aerospace, Glendale, CA). The nonchromated spray primers were water-borne Dexter lO-PW-22-2 (X) (Dexter Corporation, Waukegan, IE) and water-borne Spraylat EWAE118 (D) (Spraylat Corporation, Chicago, IE). 

The plasma deposition step when the anode assembly was removed in flow system is designated by the process code Tfs. In the plasma deposition in a closed reactor system, the reactor chamber was first pumped down to less than 1 mtorr. The reactor chamber was then isolated from the pumping system by closing the main valve located in between. TMS gas, controlled by an MKS mass flow meter (model 247C), was then fed into the reactor. After the system pressure reached a preset point, TMS gas feeding was stopped and DC power was applied to initiate the glow 

The main aim of SAIE is the complete elimination of heavy metals from the coating systems an approach that primarily relies on tenacious water-insensitive adhesion and good barrier characteristics of a primer has been taken. It should be pointed out that this approach is theoretically incompatible with the approach that utilizes the primers with corrosion inhibitors, e.g., chromated primers. This is because a primer with super barrier characteristics would not allow the migration of inhibitors and would not provide enough water for their electrochemical reaction to form corrosion protection products, as described in Chapter 28. In order to further elucidate the SAIE concept, both chromated and nonchromated spray primers were employed to generate two types of plasma coating-modified systems, and their corrosion protection behaviors were investigated in this study. 

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