Experimental study of the wear behavior of tunnel boring machine disc cutter ring under Fe-based coatings

The extremely high wear rate of disc cutter rings of tunnel boring machines (TBMs) limits their tunneling efficiency and increases their cost. The surface properties of the cutter ring significantly affect the wear rate. In this study, the effect of coatings on the cutter wear rate and wear mechanism under actual working conditions was investigated by comparing the wear test results of three different surface properties of reduced scale cutter rings with granite. The three cutter rings' vertical load, vertical vibration, mass loss, microhardness, temperature, surface morphology, and wear debris were compared. The results demonstrated that the coating had a profound effect on the wear rate of the cutter ring. The wear rate of the Fe-based amorphous-coated cutter ring was 20.3% of that of a conventional cutter ring. The wear mechanisms of the conventional cutting ring were ploughing and microcutting, whereas those of the coated cutting ring were microcutting and microcracking. Surface cracks in the Fe-based amorphous coated cutter ring have a negligible effect on its mass loss. The coatings peeled off more quickly with more hole defects. These results have guiding significance for increasing the wear resistance of disc cutters and improving their service life.