Deposit Test of Copper Plating

The thickness of copper in zinc die casting is measured on magnified microsections, or by anodic dissorlution in accordance with colometric principles. Magnetic instruments can be used for measuring the thickness of copper deposits on steel.

Copper plated steel wire for electrical cable is tested for thickness and thickness uniformity, electrical conductivity, and tensile strength. Electroformed shapes are frequently given physical tests, in order to control strength and ductility, by determining such properties as hardness, tensile strength, elongation and resistance to impact or denting.

Copper is deposited from the sulfate bath as FCC crystals that are randomly oriented, unless deposited at less than 1.5 A/dm2, when the basis metal can exert an influence on the structure so that crystals in the basis metal and plate are oriented similarly. Hardness has generally been associated with fine grains, yet it can be increased by introducing crystal orientation in the absence of grain refinement.

Grain orientation from the basis metal into sulfate copper deposit has been detected by many investigators. Thus the structure of the deposit is often influenced by that of the basis metal. The basis metal structure was reproduced in an acid solution before plating, but was not reproduced when the basis metal was cleaned by not dipped in acid solution before plating. The grain size of the substrate appeared to influence the reproduction of the basis metal structure in the copper deposit. The structure of copper electrodeposited from sulfate solution was not influenced by dislocations such as pits in the substrate surface, unless the etch pits contained oxides or sulfides. Oxide and sulfide particles in the surface layer of the substrate behaved as nucleation sites.

Other articles:

• Bright Anodized Aluminum
• Performance Plated Aluminum