Process for steam conversion coating aluminum

A conversion coating process for pretreating the surface of a metal selected from a group consisting of aluminum and aluminum alloys in order to increase overlying coating adhesion and diminish corrosion and abrasion, the process comprising the steps of:

• deionizing a feedwater supply;
• boiling the deionized feedwater supply to form a pure steam;
• delivering a flow of the pure steam into a chamber, the flow having an initial direction of travel;
• causing the pure steam to flow in a swirling pattern;
• circulating the swirling flow of pure steam through the chamber and out an exit port so as to maintain a non-static flow environment;
• subjecting a surface of a metal selected from a group consisting of aluminum and aluminum alloys with the swirling pure steam so as to generate an oxide layer;
• and
• subjecting the resulting oxide layer to a pressure across its face by the swirling flow of steam so as to prevent the crystallization of the oxide layer in a defined and orderly manner.

A conversion coating process for pretreating the surface of a metal selected from a group consisting of aluminum and aluminum alloys in order to increase overlying coating adhesion and diminish corrosion and abrasion, the process comprising the steps of:

• deionizing a feedwater supply;
• boiling the deionized feedwater supply to form a pure steam;
• directing a flow of the pure steam into a chamber, the flow having an initial direction of travel;
• directing the flow of pure steam at a baffle to divert the flow from its initial direction of travel and generate swirling flows of pure steam;
• circulating the swirling flows of pure steam through the chamber and out an exit port so as to maintain a non-static flow environment;
• subjecting a surface of a metal selected from a group consisting of aluminum and aluminum alloys with the swirling pure steam so as to generate an oxide layer;
• and
• subjecting the resulting oxide layer to a pressure across its face by the swirling flow of steam so as to prevent the crystallization of the oxide layer in a defined and orderly manner.