Abstract: An aqueous composition for the electrolytic deposition of a chromium coating on the surface of a substrate is disclosed, in which it has a pH of between 0 and 1 and which contains a trivalent chromium salt, glycine, an alkali metal salt, an aluminium salt and, optionally, an ammonium salt. The chromium plating process according to the invention comprises the immersion of the substrate to be treated in this composition and the application of a current between this substrate and an anode. This process makes it possible to form a high-quality chromium coating on the entire surface of the substrate.

Abstract: An electrolyte and a method to electroplate a metal on a substrate using the electrolyte are described. The electrolyte includes an imidazolium compound, a metal salt, and water. The imidazolium compound has formula (I) wherein R1, R2, R3, R4, and R5 are each independently selected from an H atom and an organic radical. L? is a compatible anion. The metal salt can include but is not limited to salts of the metals Li, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, Bi, La, Ce, Al, Ag, Au, Ga, V, In, Nb, Mo, and W.

Abstract: An electrolyte and a method to electroplate a metal on a substrate using the electrolyte are described. The electrolyte includes an imidazolium compound, a metal salt, and water. The imidazolium compound has formula (I) wherein R1, R2, R3, R4, and R5 are each independently selected from an H atom and an organic radical. L? is a compatible anion. The metal salt can include but is not limited to salts of the metals Li, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, Bi, La, Ce, Al, Ag, Au, Ga, V, In, Nb, Mo, and W.

Abstract: Process suitable for providing a substrate with a protective coating based on chromium, including a chromium matrix in which solid particles are distributed. The process includes a step of electrodeposition of the coating carried out by passing an electric current between a cathode or cathodes of the substrate to be coated and an anode or anodes. The cathode(s) and anode(s) are immersed in an electroplating solution, wherein the electroplating solution is based on an aqueous solution including trivalent chromium obtained from the reduction of chromic acid by a reducing agent, and contains solid particles.

Abstract: The present invention relates to an electrolysis bath based on trivalent chromium.This bath is characterized in that it contains a trivalent chromium halide which is neither chelated by a chelating product of chromium nor accompanied by a special organic solvent.Due to simple operational characteristics, this bath makes it possible to obtain commercially interesting results since, with respect to the color, thickness and hardness of the deposits obtained, very close to those of conventional baths based on hexavalent chromium, this with the advantage, over the latter, of having a speed and a yield of deposit which are much greater and conditions of use which are less toxic and less polluting.

Abstract: A process for the electrolytic deposition of chromium by means of a bath of trivalent chromium is characterized in that it uses, as electrolyte, a solution which is obtained by careful reduction of the chromic acid in a sulfuric medium by an excess of a reducing agent of the alcohol type, such as methanol. Subsequently this solution is diluted with water without indispensable addition of additional products. The electrolysis is effected without separation of the anodic and cathodic compartments at an anode-cathode potential difference greater than 6 volts, the cathodic current density being of the order of 10 to 40 amperes per dm.sup.2, the concentration of trivalent chromium ranging from 0,1 to 1 ion-gram per liter and the pH from 1 to 1,5.