Investigation into effect of scratch length and surface condition on Cerchar abrasivity index

The Cerchar abrasivity index (CAI) obtained from Cerchar abrasivity tests is an indicator of abrasiveness of rocks, and widely used for the estimation of bit/cutting tool life and wear rates in various mining and tunnelling applications. The effect of scratch length on CAI is investigated in this study by use of West apparatus and 6 different steel styluses with Rockwell Hardness of HRC40-42, HRC44-46, HRC48-50, HRC50-52, HRC54-56, and HRC58-60. The tests are carried out on 15 different rock samples (sedimentary, igneous, and metamorphic) on which rough and sawn cut surfaces with scratch lengths varying between 2 mm and 20 mm with an increment of 2 mm, thus resulting in total 27,000 scratches. It is observed that the CAI values between 85% and 93% are reached at the sliding distance of 10 mm while about the final CAI value of 99% is reached at 15 mm. It is also observed that the CAI values on rough surfaces are about 18% higher than those on sawn cut surfaces. Besides, it is determined that the most suitable surface condition in CAI test is sawn cut surfaces according to the coefficient of variation of CAI values in measurement depending on the stylus hardness and the measurement surface condition. © 2016 Elsevier Ltd
National Council for Scientific Research: 110M579
This study was supported by TUBITAK (The Scientific and Technological Research Council of Turkey) under the project number of 110M579. The authors also gratefully acknowledge B?lent Ecevit ?niversitesi (the project number of 2012-17-11-04). We acknowledge the useful and constructive comments of Assoc. Prof. Hamit Ayd?n (B?lent Ecevit University, Turkey), Prof. Sair Kahraman (Hacettepe University, Turkey), Prof. Hanifi ?opur (?stanbul Technical University, Turkey), and Assoc. Prof. ?etin Mekik (B?lent Ecevit University, Turkey). Further, we would like to extend our thanks to the reviewers of this article for their valuable observations and suggestions to enhance the quality of this work.