Efficiency of Rock Cutting and Wear Behavior of Coated Bits via Lab-Scale Linear Rock-Cutting Machine: Experimental Approach

Abstract In mining industries, the prime concern is to overcome the challenges of using conical cutting bits for excavating hard and abrasive rocks. In this research, a speculative investigation was performed to measure the efficiency of rock cutting and identify the wear behavior of aluminum titanium nitride-coated conical cutting bits. A newly designed and customized shaping machine is used with a triaxial force dynamometer to cut the rock samples linearly and to calculate their associated powers. Coated conical bits have a maximum hardness range of 2,291 to 2,459 HV, and uncoated conical bits possess minimum hardness range of 1,945 to 1,948 HV. Two rock samples of fine-grained sandstone with UCS of 83.77 and 97.00 MPa are used in this study. Various cutting ranges were investigated and the best range of cutting parameters are identified between the variables, such as cutting forces and extracted volume of rock, cutting effectiveness, specific energy produced while cutting, and bit wear. The percentage decrease in wear rate of a coated conical bit compared with an uncoated conical bit is 40.36%, 52.28%, and 53.30% for Rock 1 and 42.67%, 54.76%, and 60.90% for Rock 2 under varying depths of cut. The worn surface has been significantly investigated through scanning electron microscopy and energy dispersive X-ray analysis. The output of this study helps in extending the application of a surface miner for excavating harder rocks in mines.