基于金刚石钻头干钻时出现较高摩擦热的现象,采用MoS2作为胎体润滑剂,用电镀法制备MoS2-Ni复合胎体材料,以减小胎体的摩擦因数、降低摩擦热;并研究电镀工艺对MoS2复合镀层的显微硬度和低温低压下复合镀层对胎体摩擦性能的影响。结果表明:随镀液中MoS2浓度增大,镀层的显微硬度和胎体的摩擦因数降低,当MoS2浓度大于0.5g/L时,镀层的显微硬度和胎体的摩擦因数变化不大;随镀液pH增大,镀层显微硬度降低,胎体的摩擦因数先减小后增大,当镀液pH增大到4.0后,镀层的显微硬度变化不大,胎体摩擦因数达最小值;随镀液电流密度增大,镀层显微硬度和胎体摩擦因数先减小后增大,当电流密度增大到2.5A/cm2时,镀层的显微硬度和胎体摩擦因数达到最小值。摩擦磨损后的胎体材料形貌分析表明,控制好电镀工艺条件,可实现低温低压下MoS2-Ni复合材料对胎体的润滑作用。
Based on the high friction heat produced when diamond bits drilling in dry condition, a new thought of preparing the MoS2-Ni composite with electroplating method by adopting MoS2 as lubricant is presented and then accomplished to decrease the matrix friction coefficient and the friction heat. The effect of the electroplating process on the micro-hardness of MoS2 composite coating, and the coating on the friction performance of the matrix under low temperature and low pressure were studied. The results show that the micro-hardness of the coating and the friction coefficient of the matrix decrease gradually with increasing MoS2 concentration, while the micro-hardness of the coating and the friction coefficient of the matrix decrease little when the concentration of MoS2 reaches 0.5 g/L. With increasing plating solution's pH, the micro-hardness of the coating decreases gradually and the friction coefficient of the matrix decreases firstly then increases. The micro-hardness of the coating decreases little and the friction coefficient of the matrix reaches the minimum when the pH reaches 4.0. With increasing current density, its micro-hardness of the coating and the friction coefficient of the matrix decrease firstly then increase, and the minimum values of which are obtained when the current density reaches 2.5 A/cm2. The feature analysis of the matrix after friction and wear showthat the MoS2-Ni composite can lubricate the matrix under low temperature and low pressure if the electroplating technique is well controlled.