High-strength and wear-resistant precious metal sliding electrical contact materials

Sliding electrical contact elements facilitate the transmission of signals and power between continuously rotating components, with broad applications in aerospace, transportation, and precision instrumentation. The outstanding chemical stability and remarkably low contact resistance of gold and silver, both considered precious metals, make both ideal choices for sliding electrical contact materials. However, the low hardness and poor wear resistance of gold and silver pose significant challenges, severely limiting the service life of sliding electrical contact materials and risking device failure. A primary research focus involves the alloying of gold and silver via elemental modification, aiming to enhance the wear resistance of precious metal sliding electrical contact materials. This review covers three key material categories. Gold-based alloys are distinguished by exceptional mechanical properties and chemical stability, making the ideal choice for high-load, low-speed, low-power applications in corrosive environments. Silver-based alloys offer a cost-effective solution with superior electrical conductivity, and are well-suited for medium-to-low load and speed, but high-power scenarios. Furthermore, silver-based composites offer similar cost advantages and additionally possess self-lubricating properties, making them particularly suitable for applications involving medium-to-low loads under high-speed operating conditions. The selection of lubricant depends on the current level and the atmospheric conditions in the service environment. This research may provide new insights for developing wear-resistant, highly conductive precious metal sliding electrical contact materials.