石墨粒度对自润滑孕镶金刚石钻头性能的影响

Influence of Granularity of Graphite on the Properties of Self-lubricating Impregnated Diamond Bit

为了降低干钻过程中金刚石钻头的热损伤,提出了"自润滑孕镶金刚石钻头"的概念,即在钻头胎体中添加固体润滑剂——石墨。研究了石墨粒度对钻头胎体的抗弯强度、洛氏硬度以及在无冷却液的条件下与花岗岩对磨时的摩擦系数和磨损量的影响,以及对钻头工作层的干摩擦性能的影响。结果表明,胎体中添加的石墨粒度越细,胎体的抗弯强度越低,硬度越大,与花岗岩干摩擦的摩擦系数越低,但磨损量越大;工作层中添加的石墨粒度越细,金刚石的寿命越长。

To reduce thermal damage of the diamond bit when drilling without coolant, a concept of self-lubricating impregnated diamond bit is proposed. It means that graphite used as solid lubricant was added into the bit matrix. Then the influence of granularity of graphite on bending strength and rock hardness of the bit matrix was studied. The influence of graphite granularity on frictional properties without coolants for the bit matrix was studied. The results show that, with the decrease of the granularity of graphite particles, the hardness of the matrix increases, the bending strength of the matrix is reduced, the friction coefficient of the friction pair is reduced, and the wear loss of the matrix is increased. With the decrease of the granularity of graphite particles, the life of the diamonds in the works layer was increased.