Eigenschaftsmodifikation von chrombasierten Schichtsystemen durch modularen Einbau mikro- und nanoskaliger Dispersionspartikel

The properties of chromium coatings, electrodeposited from hexavalent electrolytes, can be modified by incorporation of micro- and nano-sized particles. To this end, particulate carbides and oxides of aluminium, silicon, tungsten and titanium were incorporated. Particle diameters were in the range 10 to 20 nm and 1 mm respectively. The incorporation of these particles and the manner in which they modified deposit properties was not directly measured, being instead inferred from measurements of hardness and surface energy (the latter using wetting measurements). The most pronounced modification of the chromium coating was found at an electrodeposition temperature of 40 ºC, using as additions, nanoparticles of alumina, silica and titania. The process offers the advantages of reduced electrolyte temperature and increased current efficiency