ADHESION AND LAYER FORMATION FOR ARC AND FLAME SPRAYING (HAFTUNG AND SCHICHTAUFBAU BEIM LICHTBOGEN- UND FLAMMSPRITZEN).
Abstract:
A study was made on metal spraying performed by gas and arc processes. The microphenomena which occur with individual metal droplets as well as the overall process are described. The microphenomena deal with both chemical and physical kinetic behavior of the droplets. In this investigation, the metals steel, copper, molybdenum and aluminum as sprayed particles on steel, aluminum, copper and asbestos substrates are treated in detail. It is shown that impurities in the metal being sprayed and the atmosphere through which the droplets pass to the substrate and the substrate surface energy greatly affect the composition and adhesion of the sprayed layer to the substrate. The oxidation of the droplets was studied in detail. Unique electron microscopic photographic techniques were developed as were special adhesion testing methods. The adhesion mechanism was investigated theoretically, and experimental evidence in support of the theories is presented.