Study of the Antiwear Properties of Potassium Borate as an Oil Additive

The antiwear properties of potassium borate as an oil additive, the effect of dispersant calcium sulfonate on the antiwear property of potassium borate was evaluated using a Four-ball Machine. Auger Electron Spectroscopy (AES) and X-ray Photoelectron Spectroscopy (XPS) were used to examine the composition and the valence state of boron on the worn surfaces. It was shown that potassium borate posseses a good antiwear function since the formation of a deposited potassium borate film. The wear rate increased as the potassium borate concentration increased, which was related to the weak film strength for surface film containing more potassium borate. No B2O3 and FeB were detected by XPS, the boron on the friction surfaces was in the form of K2B4O7, which is soluble in water. The dispersant calcium sulfonate has great effect on the antiwear properties of potassium borate, which increased the wear rate significantly even though it's concentration is 0.1%(wt).AES analysis revealed that strong sulfur (S) and boron (B) peaks appeared, so a weak deposited film strength to steel surface mechanism was proposed.