EP 0668375 B1 19990113 - Process for forming composite galvanic coatings of hard chromium with a disperse phase, and wear-resistant coating formed thereby
Title (en)
Process for forming composite galvanic coatings of hard chromium with a disperse phase, and wear-resistant coating formed thereby
Title (de)
Verfahren zur Herstellung galvanischer Dispersionsüberzüge von Hartchrom sowie auf diese Weise hergestellte verschleissfeste Überzüge
Title (fr)
Procédé pour former un dépÔt électrochimique composite de chrome dur et revêtement résistant à l'usure ainsi obtenu
Publication
Application
Priority
IT TO940101 A 19940218
Abstract (en)
[origin: EP0668375A1] A process applicable to components subjected to chafing, such as internal combustion engine piston rings and similar, and wherein, after preferably first depositing a first continuous galvanic layer of Cr in a conventional bath, at least a second layer of Cr is deposited galvanically in a chromium plating bath in which is dispersed a predetermined concentration of 0.1-20 mu m particles of a nonmetal insoluble in the bath, and using a pulsating cathode current varying cyclically in time between a minimum and maximum value, so that the second Cr layer presents microcracks with a predetermined distribution, and the nonmetal particles are included partly inside and partly outside the microcracks, while at the same time limiting inclusion in the layer of the hydrogen developed in the bath. <IMAGE>
IPC 1-7
IPC 8 full level
C25D 15/02 (2006.01)
CPC (source: EP)
C25D 15/02 (2013.01)
Designated contracting state (EPC)
DE GB NL
DOCDB simple family (publication)
EP 0668375 A1 19950823; EP 0668375 B1 19990113; DE 69507172 D1 19990225; DE 69507172 T2 19990722; IT 1267394 B1 19970205; IT TO940101 A0 19940218; IT TO940101 A1 19950818
DOCDB simple family (application)
EP 95102258 A 19950217; DE 69507172 T 19950217; IT TO940101 A 19940218