Abstract: A method for forming a ceramics film on the surface of a substrate comprises performing spark discharge in an electrolytic bath, wherein the electrolytic bath comprises an aqueous solution of a water-soluble or colloidal silicate and/or an oxyacid salt to which ceramics fine particles and/or specific fine particles are dispersed and the spark discharge is carried out in the electrolytic bath while ensuring the suspended state of the ceramics particles and/or the specific fine particles in the electrolytic bath. The method makes it possible to effectively form, on the surface of a metal substrate, ceramics films having a variety of color tones as well as excellent insulating properties and hardness. Moreover, it further makes it possible to effectively form a composite ceramics film having excellent wear resistance on the surface of a metal substrate.

Abstract: A method for forming a ceramic coating on a substrate comprises immersing the substrate such as stainless steel in an aqueous solution containing a silicic acid compound such as sodium silicate and/or a metal salt of oxygen acid such as an aluminate, and irradiating the substrate with a laser beam. By this method, a dense and fine ceramic coating can be uniformly formed on the substrate without using an apparatus of large scale required in the gas phase method and without heating the system to a high temperature.

Abstract: The invention provides an electroplating bath for forming a zinc-nickel alloy coating consisting essentially of water, about 1 to 70 grams/liter of zinc, about 0.6 to 118 grams per liter of nickel, at least one compound from the group consisting of (i) aliphatic amines in an amount not more than 16 grams/liter, (ii) polymers of aliphatic amines in an amount not more than about 20 grams per liter and (iii) a compound selected from the group consisting of hydroxyaliphatic carboxylic acids and salts thereof in an amount from 0 to 2 mols/liter, said bath having a pH of more than 11. The invention also provides an electroplating method for forming a chromate coating on a zinc-nickel alloy coating electrolytically deposited from the electroplating bath defined in the preceding sentence on electrically conductive metalics matrix material, and forming a chromate coating on the zinc-nickel alloy coating by means of a chromate treatment.