Study on Cold Spray Coating of Ag-Ni for Electrical Contact

Electrical contact device operate the opening and closing of an electrical circuit or mechanical contact of electrical equipment. The electric contact material may cause problems such as excessive wear and sticking due to the high pressure and heat generated by the arc generated between the electrodes. Therefore, materials are required to be thermally stable, good in thermal/electrical conductivity, and excellent in abrasion resistance properties. Ag-CdO is widely used as an electrical contact material. However, heavy metal Cd has been restricted in use worldwide because it causes environmental pollution. Therefore, it is necessary to develop materials to replace Ag-CdO.

In this study, the coating was produced using cold spray process with Ag, Ni and Ag-Ni coated powders. Ag-Ni coated powder was subjected to heat treatment to improve the deposition efficiency. Ni fraction and hardness of the coating were evaluated. Electrical and thermal conductivity were measured. The hardness value of 110 HV or more required for material was obtained. As a result, Ag-Ni cold spray coating technology could be regarded as a new technology to simplify the manufacturing process and reduce cost in the field of electrical contact materials, compared with the conventional repetition process through melting, extrusion, rolling and heat treatment.