Friction and Wear of Phosphate Laser Glass in Dry Air and Water

Using a reciprocating sliding tribometer, the friction and wear behaviors of phosphate laser glass were investigated against an alumina ceramic ball in dry air and water. Experimental results show that friction coefficients in water were lower than that in dry air, where liquid water played a lubrication role in the friction and wear process. Under the same load, the wear depth and wear volume of phosphate laser glass in water was much greater than that in dry air. Liquid water promoted the material removal of glass, and the wear mechanism in water was dominated by tribochemical wear. On the other hand, the subsurface damage of phosphate laser glass was mild in water, which is the result of a significant decrease of shear stress under water lubrication. In dry air, due to the pure mechanical action, the glass damage was dominated by crack initiation and brittle exfoliation, combining with a severe subsurface damage.