The challenges pertaining to low rock-breaking efficiency and high drilling cost in deep hard formation and hot dry rock (HDR) are highly pronounced. A novel drilling technology, the combined thermomechanical drilling technology, has demonstrated its potential to enhance the rate of penetration. However, the rock-breaking mechanism for thermal spalling-assisted rock breaking by the drilling bit remains inadequately understood. This paper establishes a model of thermal spalling-assisted rock cutting (TSARC) by polycrystalline diamond compact (PDC) cutter to investigate the influence of different heating and cutting parameters on the rock-breaking efficiency. The outcomes indicate that the brittleness of heterogeneous rock decreases while its plasticity increases after undergoing high-temperature heating. Consequently, this reduces the cutting force and mechanical specific energy (MSE) of the PDC cutter. In the TSARC process, an increase in heating power corresponds to an increase in rock-breaking efficiency. However, once a certain temperature threshold is reached, the rock surface suffers complete destruction due to the high temperature, while the MSE remains unchanged. When considering the same heating parameters, the MSE of TSARC and traditional rock cutting (TRC) is directly proportional to the cutting velocity. The larger the cutting depth and rake angle of TRC, the higher is the rock-breaking efficiency. In contrast, the smaller the cutting depth and rake angle of TSARC, the higher is the rock-breaking efficiency, and the cutting force can be reduced by up to 94%. This study also includes an experimental program to examine the effect of thermal source height and velocity on the rock-breaking behavior of TSARC. It was observed that in comparison to TRC, when the thermal source movement speed of TSARC is 7.5 cm/s or the thermal source height is 5 cm, a significant reduction of 47.37% and 54.1% in the average cutting force, respectively, can be achieved. The results are of positive significance for increasing the rock-breaking efficiency and drilling speed in deep hard and HDR formations.

深部硬地层和干热岩石（HDR）中破岩效率低和钻井成本高的挑战非常突出。一种新颖的钻井技术，即热机械联合钻井技术，已显示出其提高钻速的潜力。然而，对于钻头热剥落辅助破岩的破岩机理仍知之甚少。建立聚晶金刚石复合片（PDC）刀具热剥落辅助岩石切削（TSARC）模型，研究不同加热和切削参数对破岩效率的影响。结果表明，非均质岩石经过高温加热后，脆性降低，塑性增加。因此，这降低了 PDC 刀具的切削力和机械比能 (MSE)。在TSARC工艺中，加热功率的增加对应于破岩效率的增加。然而，一旦达到一定的温度阈值，岩石表面就会因高温而完全破坏，而MSE则保持不变。当考虑相同的加热参数时，TSARC和传统岩石切割（TRC）的MSE与切割速度成正比。TRC的切削深度和前角越大，破岩效率越高。相比之下，TSARC的切削深度和前角越小，破岩效率越高，切削力最多可降低94%。这项研究还包括一个实验计划，用于检查热源高度和速度对 TSARC 破岩行为的影响。结果发现，与TRC相比，当TSARC的热源移动速度为7.5 cm/s或热源高度为5 cm时，平均切削力可分别显着降低47.37%和54.1%。实现了。研究成果对于提高深层硬地层和HDR地层破岩效率和钻进速度具有积极意义。