The influence of microwave irradiation on thermal properties and fracturing mechanism of basalt in rock excavation

• Microwave irradiation induces two distinct failure modes in basalt: high-temperature melting (>300°C) and low-temperature bursting (<200°C), with high power altering the failure mode and temperature-time relationship. • Temperature distribution under microwave heating exhibits a wave pattern, promoting transverse tensile cracks and enhancing fracturing efficiency. • Dehydration of basalt above 200°C triggers macroscopic crack initiation, while microscopic fracturing is driven by thermal stresses and steam pressure, especially at high power. • The findings provide theoretical and technical support for efficient deep earth resource exploitation, reducing energy consumption and cutter wear in mechanical excavation.