Adherent metallization of plastic composites

Carbon fiber reinforced plastic composites were coated by means of the low temperature arc vapor deposition process. Metallic coatings of copper and chromium were deposited at temperatures between 90 and 140degC. Before the deposition, the composite samples were pretreated by different substrate cleaning methods which included washing in an alkaline solution, etching in potassium permanganate or immersing in an oxygen-nitrogen plasma. The adhesion strength of the coating, as measured by a Z-axis pull test, strongly depended on the pretreatment method as well as on the chemical nature of the metallic coating. High coating adhesion can be achieved even at low substrate temperatures. (orig.)