In a method for chromium upgrading of interconnects made of ferritic steel to be used in solid oxide cell stacks, comprising the steps of shaping the interconnect, depositing a coating comprising Cr on at least one surface of the shaped interconnect and performing one or more thermal treatments at a temperature below 1000° C., the resulting Cr concentration near the surface of the interconnect is higher than the Cr concentration in the ferritic steel before shaping. Specifically, the average Cr concentration of the shaped interconnect is increased to 26 wt % Cr or higher.

A microporous plating solution characterized by containing nonconductive particles and polyaluminum chloride allows for easy preparation of positively charged nonconductive particles and is highly stable. Then, a method for performing microporous plating on an object to be plated, characterized by plating the object to be plated in the microporous plating solution results in a favorable number of micropores in the plating.

Provided herein is a composition for forming a metal deposit on a substrate. The composition consists essentially of a carboxamide, trialkylamine chloride, and a metal salt. The carboxamide comprises Formula (I). The trialkylamine chloride and the carboxamide are in molar ratio between 1:1 and 1:30 to form an ionic liquid. The trialkylamine chloride is trimethylamine chloride (TMACl), triethylamine chloride (TEACl), triethanolamine chloride, or combinations thereof. The metal salt has the formula MX.sub.y, wherein M is a metal, X is a halide, and y is an oxidation number of M, the metal salt being in a concentration between about 0.2 and about 1.5 moles per liter of the ionic liquid. The metal deposit has an average grain size between about 0.2 μm and about 3 μm and contains less than about 1 mol % of each oxygen, carbon, and chlorine.

Provided herein is a composition for forming a metal deposit on a substrate. The composition consists essentially of a carboxamide, trialkylamine chloride, and a metal salt. The carboxamide comprises Formula (I). The trialkylamine chloride and the carboxamide are in molar ratio between 1:1 and 1:30 to form an ionic liquid. The trialkylamine chloride is trimethylamine chloride (TMACl), triethylamine chloride (TEACl), triethanolamine chloride, or combinations thereof. The metal salt has the formula MX.sub.y, wherein M is a metal, X is a halide, and y is an oxidation number of M, the metal salt being in a concentration between about 0.2 and about 1.5 moles per liter of the ionic liquid. The metal deposit has an average grain size between about 0.2 μm and about 3 μm and contains less than about 1 mol % of each oxygen, carbon, and chlorine.

A trivalent chromium plating solution containing a trivalent chromium compound, a complexing agent, a conductive salt, and a pH-buffering agent, and further containing an organic compound having 2-4 carbon atoms and three or more chloro groups, and a trivalent chromium plating method using the same provide a practical trivalent chromium plating with enhanced corrosion resistance as compared to the ordinary trivalent chromium plating.

A trivalent chromium plating solution containing a trivalent chromium compound, a complexing agent, a conductive salt, and a pH-buffering agent, and further containing an organic compound having 2-4 carbon atoms and three or more chloro groups, and a trivalent chromium plating method using the same provide a practical trivalent chromium plating with enhanced corrosion resistance as compared to the ordinary trivalent chromium plating.

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) ##STR00001##
wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 are each independently selected from an H atom and an organic radical. L.sup.− 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.

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) ##STR00001##
wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 are each independently selected from an H atom and an organic radical. L.sup.− 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.

A trivalent chromium plating solution that does not cause the problems including the occurrence of deposition failure of the plating and color unevenness, such as a brown stripe pattern, in the plating even though a metal impurity is incorporated into the plating solution, and a trivalent chromium plating method are provided by a trivalent chromium plating solution containing a trivalent chromium compound, a chloride as a conductive salt, a pH buffering agent, and a complexing agent, further containing an unsaturated sulfonic acid compound represented by the following general formula (1) (wherein in the formula (1), R.sub.1 represents a hydrocarbon group having a number of carbon atoms of from 1 to 10, hydrogen, or a halogen; R.sub.2 represents nothing or a hydrocarbon group having a number of carbon atoms of from 1 to 10; and X represents hydrogen or an alkali metal), and a trivalent chromium plating method using the same.

R.sub.1—CH═CH—R.sub.2—SO.sub.3X  (1)

A trivalent chromium plating solution having a high plating deposition rate and being practical is provided with a trivalent chromium plating solution containing a trivalent chromium compound, a complexing agent, potassium sulfate and ammonium sulfate as a conductive salt, a pH buffer, and a sulfur-containing organic compound, containing a carboxylic acid having two or more hydroxy groups and two or more carboxy groups or a salt thereof as the complexing agent, and containing a combination of saccharin or a salt thereof and a sulfur-containing organic compound having an allyl group as the sulfur-containing organic compound.