Parameterization of micro-hardness distribution in granite related to abrasive machining performance

Abrasive tool manufacturer and granite processor often cope with quite difficult selection of abrasive tool specification and abrasive machining parameters when processing various granite types. This is because hardness distribution in granite is very much scattered due to multi-mineral character. Therefore, bulk value and deviation value of granite micro-hardness were proposed as micro-hardness parameters in order to parameterize micro-hardness distribution in granite and evaluate abrasive machining performance. First, drilling, grinding and sawing experiments were conducted for 10 kinds of granite in laboratory to investigate effect of micro-hardness parameters on abrasive machining efficiency. Then, the regression formula of micro-hardness parameters and abrasive machining efficiency was considered as an evaluation mode to predict abrasive machinability of granite. Finally, sawing and polishing experiment were carried out in manufactory to validate the evaluation mode. Experimental results show that abrasive machining efficiency increases with decreasing bulk value and deviation of granite micro-hardness. In addition, there exists good correlation between granite micro-hardness parameters and abrasive machining efficiency and their regression formula may be used to evaluate the abrasive machining performance in industrial production including sawing efficiency and tool life, but actual polishing quality only relies on mineral optical property. (c) 2007 Elsevier B.V. All rights reserved.