单宁酸作为水基润滑添加剂的摩擦学特性

Tribological Performances of Tannin Acid Water Based Lubricant Additive

以含单宁酸水基润滑添加剂为研究对象,利用立式万能磨损试验机评价不同含量单宁酸水基液作为不锈钢/Si_3N_4摩擦副润滑液的摩擦学性能,并借助电化学工作站及接触角测定仪对单宁酸在不锈钢基体表面的吸附性能进行研究,探讨单宁酸减摩、耐磨机制。结果表明:在去离子水中加入少量的单宁酸可以显著改善水的摩擦学性能,然而当水中单宁酸质量浓度超过5 g/L时,材料的磨损量明显增大;单宁酸减摩抗磨作用机制在于单宁酸分子在摩擦过程中吸附到不锈钢基体表面,与铁发生配位化学反应,形成难于溶解的单宁酸铁配合物沉淀于基体表面,从而起到减摩抗磨的效果。

A systematic investigationwas carried out on a universal ball-on-disk tribometer with stainless steel/Si3N4 as frictional pairs to study the tribological behaviour of tannin acid as water-based lubricating additive under undirectional sliding.The adsorption of tannin acid on the surface of stainless steel substrate was studied by means of electrochemical workstation and contact angle meter,and the friction reducing and anti-wear mechanism of tannin acid was discussed.It is found that adding a small amount of tannin acid to deionized water can significantly improve the tribological performances of water.However,when the concentration of tannin acid in water is more than 5 g/L,larger wear is found for stainless steel.The friction reducing and anti-wear mechanism of tannin acid is due to the formation of iron-tannin acid complex on stainless steel surface during the sliding.