Copper-MAX-phase composite coatings obtained by electro-co-deposition: A promising material for electrical contacts

A new and promising composite coating system comprising copper and MAX phase particles (commercial powder consisting of Ti₂AlC and Ti₃AlC₂) was prepared electrochemically using direct current electrodeposition. The MAX phase particles, in micro-scale sizes, were successfully incorporated (up to 3 wt%) and well distributed in the copper coating. The change in the coating properties such as hardness, electrical contact resistance as well as crystallographic structure was investigated in layers having thickness values of about 50 μm. Furthermore, the behavior of the composite layers under electrical arcing conditions was studied. Beside an increase of the hardness and a slight change in the structure due to particle incorporation, it could be shown that the electrical contact resistance of the composite coatings is similar to the one of pure copper films deposited at the same conditions. An improved behavior under electrical arcing was found for the composite coatings. After the arcing experiments no significant changes of the morphology of the composite coatings were found, whereas, the pure copper layers showed melting and recrystallization. The composite layers are, therefore, a suitable alternative for electrical applications such as electrical switching devices.