| 摘要 |
PROBLEM TO BE SOLVED: To provide a nickel-tungsten alloy plating liquid and a method for forming a nickel-tungsten alloy plated film which enable the nickel-tungsten alloy plated film to be formed without using ammonia, and the plated film has a high tungsten content, high hardness, excellent corrosion resistance, excellent wear resistance and excellent mold releasability. SOLUTION: The nickel-tungsten alloy plating liquid contains as essential components: at least one kind selected from sodium salt and potassium salt of tungstic acid in an amount of 0.2 to 0.5M; nickel sulfate in an amount of 0.07 to 0.2M; ammonium citrate in an amount of 0.2 to 0.4M; and citric acid or sodium salt or potassium salt of citric acid in an amount of 0.2 to 0.4M, wherein its pH is held to 4 to 6 due to an amount of the addition of acid or alkali. In the method for forming the nickel-tungsten alloy plated film by using the plating liquid, electroplating is performed under the conditions satisfying a bath temperature of 50 to 70°C and a current density of 30 to 150 mA/cm<SP>2</SP>. COPYRIGHT: (C)2006,JPO&NCIPI
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