(H 3 BO 3) films was investigated by sliding steel and ceramic balls against boric oxide (B 2
O 3) coated steel and ceramic disks under a wide range of contact loads. Self-lubricating H 3
BO 3 films result from a spontaneous chemical reaction between water molecules and B 2 O
3 coatings in humid air. Mean initial hertzian contact pressures in the range 0.31–1.6 GPa
were created between balls and B 2 O 3-coated disks by varying the applied load and the …