Abstract The tribological behaviors of silicon nitride sliding upon sintered polycrystalline diamond (PCD) were explored via altering pH levels. High reductions in the friction and wear are achieved when sodium hydroxide solution is introduced at the contact interfaces. This reduction is found to depend on the pH value of the alkaline solution. The friction coefficient and wear loss of silicon nitride vary with pH level by more than half an order of magnitude and achieves the lowest values at pH 13. Moreover, the tribological behaviors reveal three stages versus the pH level, for which different tribochemical reactions occur due to the dissimilar hydroxyl concentrations. The dissolution of reaction products, such as Si(OH)4 and dimers (OH)3Si-O-C(OH)3, might lead to an increased proportion of hydrodynamic lubrication in the mixed lubrication regime and hence yield reduced friction and wear.

中文翻译：

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碱溶液中氮化硅对多晶金刚石的摩擦化学磨损的Ph依赖性

摘要 通过改变 pH 值研究了氮化硅在烧结多晶金刚石 (PCD) 上滑动的摩擦学行为。当在接触界面处引入氢氧化钠溶液时，可以大大降低摩擦和磨损。发现这种减少取决于碱性溶液的 pH 值。氮化硅的摩擦系数和磨损损失随 pH 值变化超过半个数量级，并在 pH 13 时达到最低值。 此外，摩擦学行为揭示了三个阶段与 pH 值的关系，在这三个阶段发生不同的摩擦化学反应到不同的羟基浓度。反应产物的溶解，如Si(OH)4和二聚体(OH)3Si-OC(OH)3，