Spray Coating of Metals. Phase 1. Feasibility Of Concept

摘要

Idaho National Engineering Laboratory (INEL) is developing a new coatingtechnique to eliminate hazardous wastes generated by electroplating processes at Air Logistics Centers. In this approach, molten metal is sprayed in fine droplets directly onto a base metal, with near-perfect conversion efficiency and without forming any hazardous liquid or airborne wastes. This phase I feasibility study confirmed that a low-melting-point metal can be deposited with excellent adhesion and negligible porosity, while strengthening the coating layer by rapid solidification. The low-temperature spray-coating system functioned smoothly, with minor modifications to complete the test matrix. The process was successful due to the basic suitability of the Controlled Aspiration Process (CAP) and to the careful, comprehensive approach adopted in development. Tin coatings were deposited onto low carbon steel at differing sets of conditions. Sealed chamber analyses found the CAP technique to be extremely safe and environmentally benign. The favorable Phase I findings suggest that spraycoating technology could be pursued along multiple paths, aimed toward several applications. jg p3.