Estimation of the Infiltration Potential of Cu-Alloy for Core Bits

Abstract

To estimate the infiltration potential in metal binders, a new parameter, the EH (Effective Infiltration Index), which can be determined with the surface tension and viscosity data of each liquid metal used in the binder, is introduced. The parameter was found to be closely related to the measured infiltration distance. As an infiltrant for core bits, the Cu-Sn alloy with a higher EH value was selected and compared with the conventional Cu-Zn alloy. For the formation of harder rock, a finer W size in the matrix is generally used to maintain the cutting rate. However, in such a case, the infiltration potential becomes lower and a fully infiltrated microstructure cannot be obtained. In this study, the matrix with the Cu-Sn alloy showed an evenly infiltrated and sound microstructure up to a W size of 1 pm and had a longer tool life than the conventional Cu-Zn alloy in a simulated drilling test.