Effects of water immersion and humid weathering on the near‐surface mechanical properties of phosphate laser glass

In this paper, the effect of water immersion and humid weathering on the near‐surface mechanical properties of phosphate laser (PL) glass was investigated using nanoindentation. The results indicate that, in the water immersion condition, the reduced modulus and nano‐hardness of PL glass decrease first, then increase and finally keeps unchanged with the increase in immersion duration; however, in the humid weathering condition, they decrease monotonously. The reaction mechanism occurring between water molecules and the glass network, especially during the later stage of the reaction process, determines the near‐surface mechanical properties and their differences when exposed to water and/or humid air. The results in this paper provide additional insight into the nano‐mechanics of glass surfaces, which also help understand the surface alteration process of phosphate laser glass during machining, storage, and serving in wet environments.