Potassium dihydrogen phosphate (KDP) crystals are important materials in high-energy laser systems. However, because these crystals are brittle and soft, machining-induced defects often emerge in KDP components. This study aimed to investigate the material removal mechanisms and characteristics of KDP during nanoscratching using Berkovich, spherical, and conical indenters. We found that KDP surface layers could be removed in a ductile mode at the micro/nanoscale and that dislocation motion was one of the main removal mechanisms. Removal characteristics are related to the stress fields generated by indenter geometries. The spherical indenter achieved a ductile removal mode more easily. The lateral force of nanoscratching increased with an increase in the normal force. The coefficient of friction (COF) followed the same trend as the lateral force when spherical and conical indenters were used. However, the COF was independent of the normal force when using a Berkovich indenter. We found that these COF variations could be accurately described by friction models.

磷酸二氢钾 (KDP) 晶体是高能激光系统中的重要材料。然而，由于这些晶体又脆又软，加工引起的缺陷经常出现在 KDP 组件中。本研究旨在研究使用 Berkovich、球形和锥形压头在纳米划痕过程中 KDP 的材料去除机制和特性。我们发现 KDP 表面层可以在微/纳米尺度上以韧性模式去除，位错运动是主要去除机制之一。去除特性与压头几何形状产生的应力场有关。球形压头更容易实现韧性去除模式。纳米划痕的横向力随着法向力的增加而增加。当使用球形和锥形压头时，摩擦系数 (COF) 与侧向力的趋势相同。然而，当使用 Berkovich 压头时，COF 与法向力无关。我们发现摩擦模型可以准确地描述这些 COF 变化。