Experimental and numerical analyses of microwave induced damage and cutability evolution in basalt

As mining extends to greater depths, microwave-assisted rock breaking offers a promising solution to enhance excavation efficiency by weakening rock structures. However, the mechanisms underlying microwave-induced damage and its influence on rock cutability remain unclear. This study presents a multiscale investigation of basalt irradiated at 3 kW and 6 kW for 30–120 s. Cutability was evaluated through uniaxial and single-cycle loading–unloading compression tests based on strain energy evolution. Acoustic emission monitoring, SEM imaging, and finite element simulations were integrated to reveal damage evolution. Results show that microwave exposure enhances basalt cutability, though the improvement rate declines with time. The incremental damage decreases with prolonged irradiation, indicating diminishing weakening efficiency at higher energy inputs. Simulations reveal spatial heterogeneity in temperature fields, with high-energy zones showing faster degradation. Early-stage damage is driven by thermal stress, mineral transitions, and selective heating, while late-stage damage slows due to microstructural changes and reduced thermal gradients. These findings clarify the thermal–mechanical coupling in microwave–rock interaction and provide theoretical guidance for optimizing power input and irradiation time. The study contributes to energy-efficient, sustainable excavation strategies, supporting the broader goals of green mining.