Graphite was used as a solid lubricant to reduce thermal damage in diamond bit when drilling without coolant. Graphite was added to the bit matrix material to reduce friction coefficient and heat. The influence of content, granularity, and surface metallization of graphite on the mechanical property and dry friction properties of the matrix, as well as the effect of diamond lifetime in the working layer were studied. Results showed that the hardness, bending strength, and friction coefficient of matrix gradually decreased with the increase in graphite concentration. Meanwhile, the abrasion loss decreased first and then increased, and the lifetime of diamond in the working layer gradually increased. With the decrease in graphite granularity, the bending strength and friction coefficient of matrix gradually decreased, whereas the hardness, abrasion loss of matrix, and diamond lifetime in the working layer gradually increased. After surface metallization of graphite, the hardness, bending strength, friction coefficient, and abrasion loss of matrix increased, whereas the lifetime of diamond in the working layer decreased. This study lays a foundation for drilling without water.

中文翻译：

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石墨添加对浸渍金刚石钻头性能的影响

在没有冷却剂的情况下，使用石墨作为固体润滑剂来减少金刚石钻头的热损伤。将石墨添加到位基体材料中以减少摩擦系数和热量。研究了石墨的含量，粒度和表面金属化对基质的机械性能和干摩擦性能的影响，以及金刚石在工作层中的寿命的影响。结果表明，随着石墨浓度的增加，基体的硬度，弯曲强度和摩擦系数逐渐降低。同时，磨损量先降低后增加，工作层中金刚石的寿命逐渐增加。随着石墨粒度的减小，基体的弯曲强度和摩擦系数逐渐降低，而硬度，基体的磨损损失和工作层中的金刚石寿命逐渐增加。石墨表面金属化后，基体的硬度，抗弯强度，摩擦系数和磨损损失增加，而工作层中金刚石的寿命缩短。该研究为无水钻井奠定了基础。