Novel method for electroplating gold on surface of molybdenum-copper alloy

Abstract

The invention relates to a novel method for electroplating gold on the surface of molybdenum-copper alloy, and belongs to the technical field of metal surface treatment. The method comprises the seven steps that acid pickling is conducted through an acid pickling solution composed of nitric acid with the volume fraction being 390-410 ml / L, sulfuric acid with the volume fraction being 390-410 ml / L and water with the volume fraction being 180-220 ml / L, activation is conducted through hydrochloric acid with the volume fraction being 45-55%, and chemical coarsening is conducted through an anode etching coarsening solution of sulfuric acid with the volume fraction being 650-750 ml / L. On the basis that flash nickel plating is directly conducted in a chemical nickel solution and then chemical nickel plating is conducted to form a nickel plating layer, good binding force of the plating layer and a base material is achieved, the binding force of the gold-plated layer and the base material and the welding performance of gold-tin solder to the gold-plated layer are enhanced, the gold-tin solder is good in wettability on the surface of the gold-plated layer after being baked for 10 min at the high temperature of 350 DEG C, the gold-plated layer does not blister or discolor, the thickness is uniform, the color is consistent, the environment is not polluted, and the cost is low. The method is suitable for machining all workpieces including precise workpieces and workpieces with complex shapes.

Description

technical field [0001] The invention relates to a new method for electroplating gold on the surface of a molybdenum-copper alloy, which belongs to the technical field of metal surface treatment. Background technique [0002] Molybdenum-copper alloy has excellent characteristics of high electrical conductivity, high thermal conductivity and small expansion coefficient, and is widely used in many fields such as national defense, aerospace, electronics, metallurgy, and chemical industry; however, the surface of molybdenum-copper alloy is easily oxidized, and the chemical properties of the oxide film Stable, resulting in poor surface wettability of molybdenum-copper alloy, difficult processing, unable to meet the application requirements of national defense and aerospace products. The molybdenum-copper alloy finally meets the standards for use in national defense and aerospace products. Based on this, the coating bonding force and weldability of the molybdenum-copper alloy gold ...

AI Technical Summary

Problems solved by technology

In order to solve the existing process of improving the bonding force of the coating through chrome plating, improving the bonding force of the coating through heat treatment of the nickel layer, and improving the bonding force of the coating through the replacement of palladium chloride, it is easy to cause environmental pollution and cannot handle precision parts and complex-shaped workpieces, and the scope of application is limited; The effect of heat treatment is poor, the benign rate of coating treatment is low, which seriously affects the surface roughness of the molybdenum-copper alloy substrate after treatment, and the palladium salt activation is expensive and the processing cost is high.