Tribological behavior of Cu-modified polymer-derived SiBCN ceramics at elevated temperature

SiBCN ceramics were prepared and modified with copper (10, 20 and 30 wt%) by polymer-derived ceramics route. The polymer-to-ceramic transformation of the precursor was investigated and the tribological behavior of the SiBCN and Cu-SiBCN ceramics at 800 °C was studied in terms of composition, microstructure, high-temperature friction properties and wear mechanism. It turned out that copper incorporation enhanced the tribological performances of the ceramics both at ambient and elevated temperatures. The average friction coefficient of SiBCN was 0.23 at 800 °C, while it decreased to 0.18 with the wear rate reduced by one magnitude order after introducing 30 wt% Cu. The generated lubricious CuO-SiO2 tribo-film originating from the tribo-chemical reaction was the major high-temperature lubrication mechanism for the Cu-SiBCN composites.